MAY 2000

Greetings from Ken Tilt -

As hard as I have tried to slow down May from coming, it arrived at a blinding pace. I feel like the tortoise left in the dust as the hare races past on the Saturday morning cartoons. I talk a good game of organization and planning but I fall prey to the same pitfalls as many of you. I hope all is well with you and your plants are growing with a purpose.

I continue to be impressed and cautiously optimistic with the interest in our industry by new growers. I stress to the new people that they are not going to enjoy quick, easy money and that much time, money, and other resources are required to get started. I also pass on the concerns of labor and difference in marketing strategies used by our industries versus traditional agriculture crops. However, many traditional agriculture crops are clinging to the ledge between survival and sale of the family farm. The nursery and greenhouse industry look much better, for now. I am also excited that we are finally drawing some attention to our value to the state and country by our legislators. Hopefully, we will receive more favorable support for our research, teaching, and extension activities as well as increased help for the Department of Agriculture for our plant inspectors and marketing activities.

I am going against traditional university research policy of publishing research in peer-reviewed journals and then passing on results to the industry. However, as long as I throw in a strong disclaimer, I think it is better to let you know what we are doing and get feedback from you if you are seeing similar results in your business. So, all I report in the following paragraphs are completed or on-going work that has not completely made it through the stringent, but necessary, academic protocol. Read the results with that in mind.


We have been working the past few years on irrigation - comparing Spin-Out and RootRight copper container treatments for suppressing roots in containers. As you know, both Lerio and Nursery Supplies are one company now so it is not pitting one companyís product against anotherís. We have reported that Spin-Out has had greater root suppression activity than RootRight but both were very effective in achieving the goal for preventing the plants from becoming root-bound. After transplanting, visual inspection of roots showed increased suppression of roots on some plants grown in Spin-Out treated containers, although the total new root mass after transplanting was not different from root growth of plants transplanted from RootRight containers. Roots from RootRight plants after transplanting had more uniform root distribution around the entire root ball,

Transplanted Blue Ice Arizona Cypress showing roots of plants
transplanted from RootRight containers on the left compared to roots of
plants transplanted from Spin-Out on the right. Bald spots
on one side usually had increased root growth on the other side.

whereas Spin-out roots had a splotchy appearance with some bald spots but with long compensating root masses in other areas of the root ball. We have looked at Arizona cypress, Leyland cypress, White cedar, Nellie R. Stevens holly and an azalea.

Blue Ice Arizona Cypress showing root reaction to
Spin-Out treatment after transplant. Many plants
showed continued root suppression with increased rooting
on other areas of the root ball.

One benefit of copper that has been promoted by liner growers is the ease of taking plants out of the containers compared to non-copper treated containers. We found this true in larger 5, 7, and 15 gallon containers too. Possible continued root suppression has been a concern of the liner growers when they stick cuttings in smaller cell packs. This year, we are cooperating with Lerio, Inc. to test several sizes of liner pots and subsequent transplant root activity when Spin-out is used on containers stuck with several woody species.


We sent out an article on irrigation last month relating the benefits of cyclic irrigation. One of the surprises we think we see is the reduced rooting out in pot-in-pot production when careful attention to water deficit replacement is practiced. One of the reasons for doing an irrigation/media test was that a nursery grower was having a big problem of Leyland cypress growing out into the surrounding soil from the socket pot. This had the obvious problem of harvesting the plants and reduced transplant success after harvest due to the loss of roots when the plants were dug. Our copper treatments obviously prevented some of the growth although roots did grow out of the drain holes in the insert containers. But, after two years in 15-gallon containers, none of our plants, even in the control treatment of one daily application of water to approximately replace the water lost the previous day, had roots out of the socket pot.

Two year Nellie R. Stevens (transplanted from 3-gallon) in 15 gallon
non-copper treated insert container showing roots exiting
the drain holes but still not enough to exit socket container.

We suspect, and are testing our theory this year, that constantly easily available water helped confine the roots to a smaller area similar to the effects on roots under drip irrigation in the field. We will be using the ultimate test of rooting champion, crape myrtle, and another species to evaluate this theory this year. We welcome you to share your experiences with us.

Another interesting finding is that the longevity of copper effects continued for two years in 15-gallon RootRight and Spin-Out containers. The continued root suppression after two years occurred both in our research at Auburn with Leyland cypress and in 15-gallon RootRight containers of Nellie R. Stevens holly at a nursery demonstration in Dothan. Both plants had good growth and were ready for sale with obvious root control continuing into the second year. The majority of the non-copper treatments were root-bound. The value of the copper treatments was evident. We also had a treatment of copper in the socket pot for roots escaping the insert pot but rooting out of the insert pot was not sufficient to give this treatment a true test.

Pot in Pot Nellie R. Stevens holly at Dothan demonstration site.


Another demonstration/research project that we are having fun with and think may have some promise is establishing slopes with landscape plants using old-fashioned nursery production techniques. Establishing banks with traditional landscaping practices can be labor intensive and expensive. A thought I picked up during my work with the nurseries in Tennessee was the method of direct sticking cuttings in the field for the production of some of our old-fashioned forsythia, crapemyrtles, quince and other easy-to-root plants. I thought that we could apply that technology to the landscape.

Direct stick forsythia in Auburn.

Last spring, with the help of Larry Quick, Lucie Gutherie, Mark Mayeske, and other county agents in Birmingham, we planted a nurse crop of weeping love grass on a steep bank at an elementary school; and with the help of Chuck Browne in Lee County, we repeated the process at a new residential project. After Christmas, we collected cuttings of crapemyrtle and forsythia, cut them into 6 to 8 inch lengths and treated them with number 2 Hormodin talc powder. We put them in bundles of 10, stuck them in a peat:perlite media in flats and put them in the cooler until early March, similar to propagation techniques of old. In early March, we fitted a 2 inch auger in a 24 volt battery-powered drill and drilled holes every 2 to 3 feet on the bank and stuck the callused cuttings 3 to 4 inches deep in 10 rows on the banks. In Auburn, we did not have access to water so we are depending on Mother Nature to help in the rooting process.

Auburn direct stick slope in residential area

In Birmingham, we used a battery-powered solenoid valve and controller and a simple gardenhose sprinkler system to apply small amounts of water 4 times a day.

Simple irrigation system on slope at Birmingham direct stick site.

Leaf emergence for direct stick crapemyrtle in Birmingham.

I have visited both sites and about 80 percent of the plants have started to leaf out. We have had some nicely spaced rains in Auburn to help the process but could use another one soon. It is too early to tell accurate results and our nursery advisors, who have done this for a while, say it will be June before we get some good growth. If all works well, we should have a beautiful bank covered with crapemyrtle and forsythia using 50 cent cuttings rather than 3 dollar 1 gallon plants. Time will tell and we will keep you posted, but we are hopeful. If it is successful, we will expand the project.

This newsletter is designed to help you find information but it is also to keep you informed of the work we are doing to serve you. Visit our Horticulture Departmental Home page if you are interested in seeing our faculty at Auburn (

The Alabama Nurserymenís Association has just announced a $10,000 annual research competitive grant fund for Auburn, Alabama A&M and Tuskegee Universities to support research and extension projects targeted at our nursery, greenhouse and landscape industries. We are excited the industry sees our value, our need and desire to serve. We look forward to being an even bigger partner in helping you solve the problems in your business. As always, let us hear from you. We welcome your comments.

The following articles are featured in this month's Something to Grow On:









DISCLAIMER: Please remember that all information presented is a summary of research and not an endorsement of any product or a recommendation of chemicals. The official labels from the manufacturing companies offer the legal and proper use and handling information for all products.


by Richard E Bir
Recently I have had phone calls from Extension agents and Green Industry professionals in 3 states asking about "poisonous" hollies in the landscape. I am not sure what stimulated this sudden interest but will share what I learned. Please remember, I am neither a pharmacologist nor a toxicologist and I certainly have done no human feeding or dose response studies. That sort of work seems more appropriate for the medical community than for a horticulturist.

Plants That Poison by Schmutz and Hamilton states that the poisonous parts on hollies are the berries. "The berries of all species are reported to be poisonous if eaten in quantity. The toxic principle is ilicin. Although not considered very poisonous, the attractive red or black berries should be considered dangerous to small children." Symptoms listed are "Nausea, vomiting, diarrhea and stupor due to depression of the central nervous system." They also note that "These are the hollies used extensively as Christmas decorations. Indians and early settlers used the leaves to make a mild brew such as 'youpon tea'." The line drawings in this book look like Ilex cornuta.

Common Poisonous Plants and Mushrooms of North America by Turner and Szczawinski, gave a more thorough treatment. In the section on English holly (Ilex aquifolium) and related species, they write "Berries and leaves may cause digestive upset; berries occasional cause of poisoning in children, but not known to be fatal." They say the berries and leaves contain theobromine, a caffeine-like alkaloid listing the same toxicity symptoms as Shmutz and Hamilton. "However, fatalities from Holly are unknown, and their poisonous properties are frequently overstated. Mild doses of the leaves or berries cause stimulation of the central nervous system, whereas higher doses cause depression of the central nervous system." IF large quantities of the berries have been ingested, they suggest that vomiting be induced followed by activated charcoal and a saline cathartic, excess stimulation caused by theobromine can be countered with barbiturates and benzodiazipines. Obviously, medical professionals need to be involved if treatment becomes necessary.

Turner notes that Yaupon holly, Ilex vomitoria, leaves were used to create a mild caffeine containing tea that was used as a substitute for coffee and tea by southerners in the American Civil War and notes a concentrated brew caused hallucinations and vomiting. Galle, in his massive work Hollies, The Genus Ilex, writes that this concentrated brew was 'black drink', prepared for Native American ceremonial use.

The South American beverage Yerba Mate or Paraguay Tea is made from the holly Ilex paraguariensis var. paraguariensis and is still widely used as a stimulating tea. It contains caffeine. The drink is made from the dried fermented foliage with many cultivars grown in South America. The process reminds me of what is done to Camellia sinensis to make the popular black teas we can purchase in our grocery stores. To my knowledge, Paraguay tea is not an important landscape plant anywhere in the United States.

When I checked for specific toxicity references to our common landscape hollies, I found almost nothing. For the native evergreen species besides Yaupon holly, Ilex opaca, I. cassine, I. glabra and deciduous species, I. decidua and I. Verticillata already mentioned, I found that the leaves of I. cassine were sometimes used by Native Americans like the leaves of I. vomitoria to make black drink. There were no other references uncovered that indicated these native species have any toxicity at all. In my more southern days, my favorite honey was gallberry honey which occurs when honeybees are foraging on the flowers of I. glabra and I. coriacea. Despite regular consumption, no toxicity was ever noted.

For the evergreen Chinese species, I. cornuta, there were medical references. The Chinese use I. cornuta in a variety of ways. The bark, leaves and fruit are used in herbal medicine for their general tonic value as well as for diseases of the kidney. Galle writes that seed oil is used in China for soap manufacturing plus a dye and gum are extracted from the bark. This very common landscape species, despite being pictured in a poisonous plants book, appears not to be toxic.

The evergreen Japanese hollies, Ilex crenata, seem to be everywhere in commercial landscapes in USDA hardiness zones 6-8. I. pernyi and I. rugosa are also evergreen hollies native to the orient which are increasingly finding their way into landscapes as selections of the species I. pernyi or as hybrids such as I. x meserveae, the blue hollies, with Ilex rugosa as a parent. The oriental cousin to our native deciduous winterberry hollies, I. serrata, has also made it into gardens as cultivars and hybrids, perhaps the most famous of which is 'Sparkleberry' from the U. S. National Arboretum. No references to medicinal uses or toxicity were found for any of these holly species.

Therefore, it seems that rather than panicking if holly berries or leaves are ingested, we should remember that Turner wrote "fatalities are unknown and their poisonous properties are frequently overstated." In my search only a few species were listed as having medicinal uses. So, if your callers can not watch what their toddlers are eating they probably have much more to fear from common beverages, condiments and household chemicals than from hollies in their landscape.


For those of you with a very active thirst for knowledge or maybe just a burning curiosity about a particular horticultural item, your prayers have been answered. The only tools required are a computer with Internet capabilities, a comfortable chair and a large block of time.

The first step in the process is to key in the URL that will bring you to the threshold of a mountain of information at Auburn University. Go to As you will see, this page has links to a number of very large databases. They are all accessible to Auburn University students, faculty and staff by entering 20-your social security number-and a 0.

The Agricola data base, for example, will search for a topic by a keyword or phrase that you input. You can limit your search to journal articles, abstracts, literature reviews, even get the latest update on a topic. You can also specify a time frame. There is a Business and Industry database that covers public and private companies, industry products and markets. Along with indices and databases are lists of current horticulture journals, associations, and societies.

(Bernice Fischman).


by John Hartman, Kentucky Pest Notes, 4/3/00

SYCAMORE ANTHRACNOSE: Two springs ago, sycamore anthracnose was devastating, but last spring much less was observed. Why were the two years so different and what is likely to happen this year? The incidence and severity of anthracnose diseases of landscape trees varies with the season. When we have cool springs with extended periods of wet weather, anthracnose diseases are worse. These conditions prevailed two years ago and people looking at their trees in late spring thought that there were mostly dead leaves and branches. In reality, the sycamores showed good resilience because they readily grew out of it and looked much better last year. Some folks worry that sycamore anthracnose may spread to their dogwood trees near by (it won't).

Sycamore anthracnose is caused by the fungus Apiognomonia veneta, and the fungus attacks both sycamore and London plane. The fungus causes twig and branch cankers, shoot blight, and leaf blight. Shoot blight, more visible and most damaging, develops after a period of cold spring weather. Although the disease is devastating, sycamores have managed to survive many disease-favorable years. Obviously, it costs sycamores much of their carbohydrate reserves to refoliate, but by early summer, regrowth is generally well under way, the new growth escaping infection because of heat and dryness. The legacy of crooked branches (because lateral shoots take over when terminals are killed by anthracnose) is the multiple shoots arising from the base of a killed branch which may be still visible many years later.

ASH ANTHRACNOSE: This disease, caused by a species of the fungus Discula, can also be seen in neighborhoods and landscapes following wet spring weather. Leaflet drop may be so great that anthracnose-infected leaflets practically carpet the walks and lawns nearby. Dead tissue appears along leaf veins or at the leaf edges because infections occur where moisture lingers longest as dew or droplets on those parts of the leaf. Ash anthracnose causes so many individual leaflets to drop in the spring that some homeowners are prompted to consider felling the tree because they think it is dying. It isn't, and the tree simply puts out a new set of leaves, again at a cost of carbohydrate reserves that might be needed to fight other kinds of stresses.

MAPLE AND OAK ANTHRACNOSE: Symptoms on these trees range from leaf spots to shoot blight and shoot cankers. Maple anthracnose may be caused by Discula sp. or Kabatiella apocrypta, and oak anthracnose by the fungus Apiognomonia quercina. Although these two diseases are less common than the sycamore and ash anthracnose disease, they, too, are found in cool, wet springs. Dogwood anthracnose, caused by the fungus Discula destructiva is only found occasionally in most home landscapes, but it is very common in forest trees and heavily shaded landscapes.

ANTHRACNOSE MANAGEMENT IN LANDSCAPE TREES: Keep in mind that two years ago carbohydrate reserves were depleted because anthracnose infected trees had to refoliate, and last year, carbohydrate reserves regeneration was limited by the drought. Thus, it is important for these landscape trees to get off to a good start this spring. Although we can't control the weather, there are some cultural practices that may help.


J. Raymond Kessler, Jr. and Guy W. Karr

The Alabama Department of Agriculture and Industries, Plant Protection Section has worked out a certification process for ornamental sweet potatoes (OSP) grown in greenhouses and nurseries. The regulation also includes morning glory (Ipomoea spp.) and bindweed (Convolvulus spp.) species. This process is necessary to protect the sweet potato industry from pests, mainly the sweet potato weevil (SPW). Compliance by in-state producers and suppliers and out-of-state suppliers is mandatory; enforcement of the regulation will begin October 1, 2000. The following are some of the major points:

- Nurseries may retain OSP plants currently on hand if two inspections conducted at least 30 days apart indicate negative for pests and disease and negative trapping for SPW. If certification is not desired by a nursery or other producer then all OSP plants on hand must be destroyed immediately.

- Once certified OSP plants may be moved anywhere in Alabama if plants are tagged or labeled. Tags must state that the OSP plant was produced in a SPW-free area of (state). Tags or labels must be placed on all containers 4-inch in size and larger. Trays of plants in containers under 4 inches in size are required to have only one tag or label per tray, firmly attached. Such tags and/or labels will be provided at cost by the Department.

- Non-sweet potato producing states must provide a tag or label stating that the OSP plants were produced in a state where the SPW is not known to occur.

- Nurseries may purchase OSP plants only from a certified source. Such certification by in-state and out-of-state producers must be based on Alabama's Rules as a minimum basis for such certification.

- Once certified, OSP plants may move anywhere, including other states provided other applicable restrictions are complied with. However, once moved into any regulated area, they cannot then moved back into a non-regulated area. Alabama's regulated areas include Baldwin, Clarke, Coffee, Conecuh, Covington, Escambia, Geneva, Henry, Houston, Mobile, Monroe and Washington counties.

- No OSP plants produced in a regulated area can be sold or distributed outside the regulated area, and no certified production is allowed in a regulated area.

If you have any questions or comments regarding the certification process, please contact your local inspector.


Check out this site from the Alabama Agricultural Statistics Service, a field office of USDA's National Agricultural Statistics Service. You will find Census information, crop weather, publications, national reports and other relevant links. The URL is:


The following results are from a study that was perfomed on the resistance of bee balm to monarda mildew on plants in North Carolina.

Early Bloom Season:
HIGHLY RESISTANT (40-50% defoliation):
  • Claire Grace
  • Marshall's Delight
  • Stone's Throw Pink

MODERATELY RESISTANT (50-60% defoliation):

  • Beauty of Cobham
  • Blue Stocking
  • Cambridge Scarlet
  • Comanche
  • Mahogany
  • Vintage Wine
POORLY RESISTANT (over 60% defoliation):
  • Cerise
  • Cherokee
  • Colrain Red
  • Croftway Pink
  • Elsie's Lavender
  • Garden View Scarlet
  • Jacob Cline
  • Jean Stewart
  • Loddon Crown
  • Monarda Didyma
  • Raspberry Wine
  • Sagittarius
  • Scorpio (Scorpion)
  • Snow White
  • Violet Queen
Late Bloom Season (July 27, 1998) Monarda Mildew ratings:
HIGHLY RESISTANT (60-70% defoliation):
  • Beauty of Cobham
  • Blue Stocking
  • Cambridge Scarlet
  • Elsie's Lavender
  • Mahogany
  • Marshall's Delight
  • Vintage Wine
MODERATELY RESISTANT (70-80% defoliation):
  • Cerise
  • Cherokee
  • Claire Grace
  • Colrain Red
  • Comanche
  • Croftway Pink
  • Garden View Scarlet
  • Jacob Cline
  • Jean Stewart
  • Loddon Crown
  • Raspberry Wine
  • Sagittarius
  • Scorpio (Scorpion)
  • Stone's Throw Pink
  • Violet Queen
POORLY RESISTANT (over 80% defoliation):
  • Monarda didyma
  • Snow White
(from a joint study by Richard E. Bir and Richard Hawke).


From Extension Horticulturist Allen Owings (Louisiana) come the following figures: Lawn and garden retail sales in the United States reached a record of $81.7 billion in 1999. This was an increase from $79.1 billion in 1998 (3.3%). The projection for sales in 2000 is $85.8 billion (5.0% growth over 1999). Retail sales of lawn and garden products for some of the sales in our region are:

Alabama - $1.405 billion
Louisiana - $1.483 billion
Mississippi - $896 million
Arkansas - $922 million


MARCH 2000

From Jackie Mullen at the The Auburn Lab

March was warm during most of the month, and spring was early with very little problem from cold damage.

Most of our March diseases were from landscape plantings. Winter damage has been noted on turf grass samples and numerous landscape trees and shrubs. Most of the winter damage this past year was probably related to drought stress last fall-winter.

Diseases seen in March were the following: anthracnose on aglaonema; ring nematode damage on bentgrass; Pythium blight on bentgrass; algal leaf spot on camellia; Pestalotia tip blight of cedar; brown patch (Rhizoctonia) on centipedegrass; Hypoxylon atropunctatum canker of red oak; Entomosporium leaf spot of photinia; fusiform rust (Cronartium quercuum f. sp. fusiforme) on pine; black spot (Diplocarpon), powdery mildew (Podosphaera), Phytophthora crown rot, Pythium root rot of rose.

In March we saw an abundance of dieback samples on landscape trees and shrubs. Foliage disease was not present on these samples. Since cold incidents this past winter and early spring were not severe, we assume that much of the dieback at this time of year relates to drought stresses last fall and winter. Samples of landscape dieback were received from Bradford pear, pittosporum, camellia, loblolly pine, Carolina jasmine, several hollies, azalea, juniper, and southern magnolia.

Algal leaf spot often occurs on camellia and southern magnolia when temperatures have been cool-moderate and wet. This leaf spot is usually not severe enough to cause significant damage to the over-all health of the plant, but the spotting is aesthetically damaging. Spots are usually reddish-brown in color and slightly raised, especially around the spot wavy edges. As spots age they may become colonized secondarily by a lichen (called Strigulla) which causes the spots to become white in color. See the Alabama Pest Management Handbook &/or ANR-857 for control recommendations. Also, sanitation of fallen spotted leaves is helpful.

J. Olive (Mobile) reported seeing several samples of anthracnose on Japanese maples. He observed leaf spot/blight (severity varied with variety), dieback and stem canker. Also in the Mobile area, fireblight has been fairly severe with most of the Bradford pears showing a dieback of a few inches. Usually the new growth covers up the damage. John reported that some folks in Mobile are finding that they do not have Bradford pears as they had thought, but, rather a more susceptible variety.

2000 March Diseases Seen In The Auburn Plant Diagnostic Lab
Aglaonema Anthracnose (Colletotrichum) Chambers
Bentgrass Ring Nematode Damage (Criconemoides) Jefferson
Camellia Algal Leaf Spot (Cephaleuros) Lee
CamelliaPythium BlightJefferson
CedarPestalotia Tip Blight.
Oak, RedHypoxylon atropunctatum Canker Lawrence
PhotiniaEntomosporium Leaf SpotLee
PineFusiform Rust (Cronartum quercuum f. sp. fusiforme) Lee
RoseBlack SpotLee
RosePowdery MildewLee
RosePythium Root RotMontgomery
RyegrassPythium BlightMobile
County locations for nursery/greenhouse problems are not reported.

2000 March Diseases Seen In The Birmingham Plant Diagnostic Lab.
submitted by Jim Jacobi
Boxwood Low pH Jefferson
Boxwood Winter InjuryJefferson
Garlic vine Powdery MildewJefferson
Ligustrum Cercospora Leaf SpotJefferson
PachysandraVolutella BlightJefferson
Red MapleBotryosphaeria CankerJefferson
RhododendronCercospora Leaf SpotBlount
Rose Powdery Mildew Jefferson
WaxMyrtleBotryosphaeria CankerJefferson

Disease Possibilities For April

April diseases are abundant, and I have included a long list of possibilities for reference purposes.

Cold damage in March is less of a problem this year than in most years. We have seen more winter damage on turf than with any other plant type. This past year the winter damage may relate more to drought than to cold. We did see some loblolly needle tip browning which may relate to fall-winter drought stress. The freezing - near freezing temperatures that occurred at night during the first week in April may cause some damage to northern wheat, other field crops, and landscapes.

Rust diseases were noticeable in March in some southern areas, and we will see them in more northern areas in April. With fusiforme rust on loblolly and slash pine, the rusty spores will cover the fusiforme swellings that develop on branches and trunks. These spores are wind-carried to oaks where infections occur on the leaves. Tiny black leaf spots on the oak will produce orange spores on lower leaf surfaces March-May. These spores are wind-carried and will cause infection of the loblolly and slash pine. Once infection occurs on the pine needles/twigs, 2-3 years may pass before mature, spore-producing galls are present. Disease control is difficult. In a nursery situation, fungicides are recommended for protective control. (See the Alabama Pest Management Handbook.) In a landscape, usually sanitation is the only practical recommendation. Watch for other rust diseases in April. Cedar-apple rust (also, cedar-quince or cedar-hawthorn rusts) will probably appear in April this year.

Peach leaf curl, caused by the fungus Taphrina, is easily recognized by the curling, distortion, and swelling it causes on infected leaves. Spores produced in the spring are carried by wind and rain to near-by peach trees where they fall onto the bark areas of twigs and branches. These spores will over-winter in protective niches in the bark. In the spring the spores may be moved by wind and rain so that they infect new leaves as they emerge and develop. For control, a dormant fungicide treatment is applied once (see the APMH) in the fall after leaf drop or in the spring before budswell.

Dogwood anthracnose is present in Alabama and has been identified in wooded (mostly state park) areas at elevations of 600 ft. and higher in the northern and northeastern sections of the state. The disease first appears as a leaf spot (brown irregular spots with purple margins) problem, usually in the lower foliage canopy. If conditions are favorable for disease development (60-70oF and wet), leaf spots will spread to involve a leaf blight and eventually a dieback problem. Blighted leaves will typically remain attached to the branches throughout the winter months. Progress of this disease is somewhat restricted in Alabama due to high summer temperatures which are not conducive to disease development and spread. To control this disease in the landscape, sanitation and application of protective fungicide sprays are recommended. See ANR-551 for a list of fungicides.

Dogwood spot anthracnose is a disease that usually is significant only in that it diminishes the beauty of the foliage and blossoms. Tiny red or brown spots may cover the bracts and leaves when weather is wet and warm. When desired, fungicides may be applied for protective disease control. See the Alabama Pest Management Handbook.

Powdery mildews are a problem on a wide variety of plants in the spring when moderate temperatures and high humidity situations exist. The fungus grows in the upper-most epidermal cells of leaves and stems. The white powdery coating on leaves and stems is characteristic of the disease. Infected leaves eventually become yellowed, withered and browned. Control involves sanitation and protective fungicide sprays. See ANR-407 for recommended fungicides. Some of the powdery mildews are also a problem in the summer.

Oedema, another spring problem on a wide variety of plants, develops when plants are subjected to cool, cloudy days and prolonged wet soil conditions. Under these conditions, water uptake by plants may greatly exceed water loss in transpiration. As a consequence, some excessively turgid cells in the leaves burst. These burst cells occur in groups on lower leaf surfaces and they appear as small corky spots. Upper leaf surface areas corresponding to the lower leaf surface corky spots become yellow spotted. The only remedy for oedema is a reduced irrigation schedule and improved soil drainage. Some woody plants damaged by edema are camellia, Eucalyptus, ivy species, jasmine, ligustrum, schefflera, and Fatsia x Fatshedera. Geranium and related plants are also prone to edema when wet, cloudy conditions exist.

Botrytis blight is a common foliage disease when conditions are wet, humid and temperatures are relatively cool (61-73oF). Flowers, leaves and stems may become covered with brown spots and blotches. When conditions are humid and cool, spore production on the spots causes lesions to appear gray with a fine, delicate, superficial, gray fuzzy layer. Disease control can be achieved by sanitation, raising temperatures, increasing air circulation (reducing humidity) and protective fungicide treatments.

While temperatures are still cool in the spring, Thielaviopsis black root rot may be a problem on cotton. Infected roots display black spots, lesions. Often root tips are affected. Infected root systems are poorly developed and top growth is consequently reduced. Control involves crop rotation away from cotton or a Batan seed treatment (1 oz./100 seed wgt).

The list below includes some common disease problems received in the lab during April of the past few years. Comments on control practices are brief. Refer to fact sheets, timely information sheets, and the Alabama Pest Management Handbook for details.

Brief Disease Descriptions and Control Recommendations
for Diseases Often Seen in April

(APMH is the abbreviation for the Alabama Pest Management Handbook).
MANY ORNAMENTALSPowdery MildewWhite-buff colored, raised dots or pads of mycelium.Fungicides; See Cir. ANR-407.
AGLAONEMABacterial Leaf SpotCircular-angular, dark, water-soaked leaf spots.Sanitation. Water at pot level.
AMARYLLISStagnospora Leaf SpotDark red blotches on leaves (5-15 mm long.)Sanitation; Cleary's 3336 or Domain.
AZALEABotrytis Petal BlightLarge irregular areas of blossoms turn brown; brown areas are covered with a gray delicate webbing during humid weather. See APMH.
AZALEAExobasidium GallSwollen blossom, leaf, and shoot galls. From mid-April to mid-May, galls change from a green to a white or pink-white color. Sanitation; removal of galls while they are still green; see the APMH.
AZALEAOvulinia Petal BlightSmall white-brown spots enlarge to be-come large browned areas on the blossoms.See APMH.
AZALEAPhytophthora Crown & Root Rot Crowns & roots become brown and water-soaked. Sanitation; See APMH.
AZALEA Rhizoctonia Aerial Blight Lower leaves become spotted and eventually whole leaves become dark brown and fall. See APMH.
BEE BALM Powdery Mildew Leaf distortions; powdery white dusty patches on foliage leaves (upper leaf surfaces) and stems. Sanitation.
BEGONIA Bacterial Leaf Spot Dark, black, water-soaked spots and blotches. Strict sanitation. Do not water overhead.
BENTGRASS Brown Patch (Rhizoctonia) Circular-irregular patches in lawn become brown. Brown lesions present on individual grass blades. Reduce nitrogen fertilization. Pro-tective fungicide treatments.
BENTGRASS Pythium Blight Foliage becomes pale brown and water-soaked. See APMH, spray guide.
BOXWOOD Macrophoma Blight (Stress) Individual branches become yellowed and brown. Tiny black pin-point dots (fruiting bodies of the fungus) appear scattered on yellowed leaf surfaces; sometimes sunken cankers develop on twigs and branches. Prune out damaged areas. Cleary's 3336 or Domain protective treatments may be applied. Identify and correct other stress problems.
CAMELLIA Algal Leaf Spot (Cephaleuros) Red-green-brown raised circular leaf spots with wavy edges. Sanitation. See APMH.
CAMELLIA Armillaria Root Rot Sudden dieback; roots show thin white mycelial layer and sometimes black thread-like structures (Rhizomorphs); honey-colored mush-rooms are also a diagnostic sign. Remove the plant with associated roots.
CAMELLIA Botryosphaeria Canker Sunken, cracked stem lesions. Sanitation.
CAMELLIA Cercospora Leaf Spot Brown circular or irregular spots of variable size. Sanitation. Cleary's 3336 or Domain protective sprays.
CAMELLIA Exobasidium Gall See Azalea. .
CAMELLIA Virus Ringspots Yellow spots and ring spots; may be a reduction in plant growth. Sanitation.
CHRYSANTHEMUM Rhizoctonia Root Rot Roots become brown, decayed and dried. Sanitation. See the APMH.
CLEYERA Anthracnose (Colletotrichum) Reddish, black spots, blotches. Orange pustules develop in spring and summer. Sanitation; Cleary's 3336 may help.
CRABAPPLE Cedar Apple Rust (Gymnosporanium) Light yellow spots (1 cm or 0.5 inch diam.) on leaves; leaf fall when spots are numerous. See the APMH.
DAYLILY Kabatiella Leaf Spot Numerous small (5 mm or 1/4 inch long) brown spots; leaf yellowing around spotted areas. The disease is often associated with stress. Sanitation.
DIANTHUS Fusarium Crown Rot Brown, dried rotted tissues on lower stems. Top dieback. Sanitation. Crop rotation.
DOGWOOD Spot Anthracnose (Elsinoe) Small (1-2 mm) red-brown spots with reddish borders occur on bracts, leaves, and young twigs. Spotting may be severe and new leaves may appear reduced in size; foliage death may result. Sanitation; See APMH.
DOGWOOD Anthracnose (Discula) This disease is characterized by leaf necrosis, twig and branch cankers and stem dieback which all begin in the lower branches and progress to the upper canopy. The disease generally begins as purple-rimmed brown spots on leaves. Spots soon develop into a general blight of infected leaves. Leaf death is followed by progressive infection and death of associated twigs and then branches. See ANR-551 or the APMH.
EUONYMUS Powdery Mildew (Microsphaera) A white powdery dusting appears on upper leaf surfaces; when disease is severe some leaf distortion occurs. See the APMH.
EXACUM Impatiens Necrotic Spot Virus New growth was stunted. Brown spots and blotches were present on the newly matured foliage. Sanitation. Control thrips.
FERN, BOSTON Colletotrichum Leaf Spot Brown spots/blotches on fronds. Sanitation. Protective sprays of Cleary's 3336.
FORSYTHIA Crown Gall Woody Galls on lower stem/trunk near the soil line. Sanitation; crop rotation to boxwood, holly, redbud or other nonsusceptible plants. See ANR-944.
GERANIUM Botrytis Blight Gray blotches occur on the foliage. Whole leaves may become involved and die. When weather is cool and moist with a high relative humidity, a delicate webbing of spores and hyphae can be seen. See the APMH. Sanitation.
GERANIUM Bacterial Leaf Spot/Stem Rot (Xanthomonas) Black spots on leaves and stems; total collapse of stem may occur; bacteria may develop in vascular system and become systemic. Strict sanitation. Bordeaux mixture protective sprays.
HOLLY, HELLERI Phytophthora Root Rot Roots become brown and decayed. Outer tissues easily pull away from the root central core. See the APMH.
HOLLY Colletotrichum Leaf Spot Black circular spots (about 5mm diam.) sometimes with cream-colored spores covering centers of spots. Sanitation; protective sprays of Cleary's 3336 or Domain may be used.
HOLLY Phyllosticta Leaf Spot Small (1-2mm diam.) black spots sometimes with a whitish center. Sanitation; protective sprays of Cleary's 3336 or Domain may be used.
HYDRANGEA Botrytis Blossom Blight Blossoms are brown-gray spotted/blotched. Sanitation. See ANR-912 for fungicide recommendations.
IMPATIENS Alternaria Laf Spot Dark brown-black, angular leaf spots. Sanitation; Kocide 101.
IRIS Heterosporium Leaf Spot Small-large (1/4-1/2 inch long), elliptical or oval shaped medium brown leaf spots. Sanitation. See APMH.
IRIS Borers/Soft Rot (Erwinia) Leaves and rhizomes become decayed with a wet, foul-smelling rot; wounds are often evident in the rhizome rotted areas. Wounds are often caused by the iris borer, but other insects may be involved. Sanitation. Especially in the fall, all diseased rhizomes should be destroyed. To further prevent & control borers, an insecticide dust may be applied weekly in the spring from new growth initiation to the beginning of June.
IVY, ENGLISH Botryosphaeria Canker Elongated, sunken, cracked stem lesions Pruning. Protective sprays of Cleary's 3336.
IVY, ENGLISH Anthracnose (Colletotrichum) Brown irregular spots (3 mm diam. & larger) that sometimes occur along veins. Sanitation. See the APMH. Use Cleary's 3336 or Domain.
IVY, ENGLISH Edema Small, brown, corky spots on lower leaf surfaces. Reduce irrigation.
IVY, ENGLISH Fusarium/Pythium Root Decay Roots become brown decayed, dried and also wet rotted. Sanitation. Banrot protective treatments.
JAPANESE PAGODA TREE Nectria Canker Sunken canker with tiny orange raised specks scattered over lesion. Sanitation.
JUNIPER Phomopsis Tip Blight Dieback. Pruning; Fungicide application. See the APMH.
JUNIPER Cedar-Apple Rust (Gymnosporangium) Large woody spherical galls (2-5 cm diam.) become covered with orange, jelly-like finger-like projections. See ANR-468.
JUNIPER Cedar-Quince or Hawthorn Rust (Gymnosporangium) Orange powdery sunken cankers. iris borer, but other insects may be involved. See ANR-468
LEYLAND CYPRESS Cercospora Needle Blight Beginning with lower branches and inner needles, blight develops and spreads upward & outward. Sanitation; protective sprays of Cleary's 3336.
LIGUSTRUM Macrophoma Leaf Spot Brown circular or oval leaf spots. Sanitation; Cleary's 3336 or Domain protective sprays.
LILAC Bacterial Leaf Spot Dark angular spots. Sanitation. Do not water overhead.
LIRIOPE Anthracnose (Colletotrichum) Brown lesions on leaves, some on leaf tips. Sanitation. Protective sprays with Cleary's 3336.
LUPIN Rhizoctonia Lower Stem Decay Dark brown, black lower stem dry rot. ---
MAGNOLIA, SOUTHERN Algal Leaf Spot (Cephaleuros) Green or red-brown, slightly raised, circular spots (1 cm diam.) with slightly wavy margins. Usually none. Sanitation.
MAGNOLIA, SOUTHERN Phyllosticta Leaf Spot Brown irregular spots (3 mm diam. and larger) which often become brown bordered with lighter centers as spots age. Sanitation. Protective sprays of Cleary's 3336 or Domain.
MAGNOLIA Stress Many older leaves become yellow and then brown; excessive leaf drop. (Some leaf senescence is normal during April-June.) Water when conditions are droughty.
MAPLE, JAPANESE Anthracnose (Kabatiella) Brown, irregularly-circular spots which often follow along leaf veins. Spots begin small, but may develop to involve larger portions of leaves. See APMH.
MAPLE, JAPANESE Phomopsis Canker Brown-gray elliptical sunken lesions on smaller branches, twigs. Sanitation.
MAPLE, RED Phyllosticta Leaf Spot Circular pale brown spots with darker brown borders (about 1/4 inch diam.). --
MAPLE, RED Pythium Root Rot (Seedlings) Roots brown, water-soaked, rotted. Sanitation. Reduce watering schedules.
MARIGOLD Alternaria Leaf Spot Black circular or irregular leaf spots (1-3 mm diam.). See APMH.
MAYHAW (HAWTHORN) Cedar-Quince Rust (Gymnosporangium) Yellow irregular spots with tiny white-orange aecial cups (spore masses) developing on lower leaf surfaces opposite upper leaf yellow spots. Removal of cedar cankers. See ANR-468.
MONDOGRASS Root Knot Nematode (Meloidogyne) Poor growth; root galls. Sanitation. See ANR-689 and ANR-856.
MONKEY GRASS (Liriope) Anthracnose (Colletotrichum) Pale brown blotches and spots on foliage. Blotch margins are sometimes dark brown or red-brown. Spots may involve large sections of leaves. Often leaf tips are involved. Sanitation; Protective sprays of Cleary's 3336 or Domain may be used.
OAK Anthracnose (Apiognomonia) Brown-black spots and irregular blotches which often develop along leaf edges and/or leaf veins. Sanitation. See APMH.
OAK Algal Leaf Spot (Cephaleuros) Gray-green or brown-red spots with irregular margins (1 cm or 1/4 inch diam.) on leaves; spots may coalesce. See APMH.
OAK Hypoxylon Canker Environmental stressed oak may develop a dieback where Hypoxylon acts to hasten the dieback problems. The fungus causes decay of inner bark and sapwood and silver gray or coal black stroma develops in the decay area, causing the bark to crack and fall away. Pruning and tree removal.
OAK Oak Leaf Blister (Taphrina) Concave-convex spots (10-15 mm or 1/4-1/2 inch diam.) on leaves. As spots age, they change from a light green-brown color to a medium-dark brown. See APMH.
OAK Powdery Mildew White powdery dust-ing on leaves; infected new growth may be deformed. Sanitation of leaves in the fall.
PANSY Colletotrichum Leaf Spot Circular gray spots with dark borders. See the APMH.
Pansy Thielaviopsis Black Root Rot Black lesions on roots. Plants are stunted. Sanitation. See the APMH.
PERIWINKLE Botrytis Blight Brown gray spot/ blight. Sanitation. Increase air circulation. In-crease temperature. See the APMH.
PERIWINKLE Phyllosticta Leaf Spot Medium-brown, circular-oval spots (5 mm diam.). Sanitation; Protective sprays of Cleary's 3336 or Domain.
PERIWINKLE Phytophthora Blight Brown lesions on leaves and stems. Sanitation. See APMH.
PERIWINKLE Thielaviopsis Root Rot Plants grow poorly. Roots have black lesions, sections, and tips. Sanitation. Cleary's 3336 protective drenches.
PETUNIA Thielaviopsis Root Rot Plants grow poorly. Roots have black lesions, sections, and tips. Sanitation; Cleary's 3336 protective drenches.
PHOTINIA Anthracnose (Colletotrichum) Light-brown, zonate spots (10-15 mm or 1/3-2/3 inch long) sometimes associated with leaf margins. Sanitation; See APMH under Entomosporium Leaf Spot.
PHOTINIA Entomosporium Leaf Spot Red-black spots (5-10 mm diam.) on upper & lower leaf surfaces. Spots generally have dark red-black borders. Spots may coalesce. Pruning; Fungicide treatment; See Cir. ANR-392.
PHOTINIA Armillaria Trunk Rot Sudden wilt and dieback; thin white mycelial layer beneath bark; sometimes black thread-like rhizo-morphs and/or honey-colored mushroom present. Sanitation--removal of plants.
PINE, LOBLOLLY Fusiforme Rust (Cronartium quercuum f. sp. fusiforme) Spindle-shaped (fusiform) swellings (galls) develop on branches and trunks. In March-April the orange spore masses (aecia) of the fungus develop on the bark surface. The powdery spores cover the whole gall area. (Oaks are the alternate host for this fungus.) Sanitation; removal of galled branches and/or trees when galls occur on trunks. See the APMH.
PINE, LOBLOLLY Lophodermium (Ploioderma) Needle Cast Last year's needles become spotted, blighted, and fall off. Tiny, black football-shaped fungal fruiting bodies can be seen on needles with hand lens. Fungicide applied in spring and fall. See APMH.
PINE, LOBLOLLY Rhizosphaeria Needle Blight, Twig Blight Needles and small twigs turn brown, die. Sanitation. See spray recommendations for needle cast; may need to continue in summer.
PINE, SLASH Rhizosphaeria Needle Blight See loblolly pine. .
PINE, VIRGINIA Lophodermium Needle Cast See loblolly pine. .
PINE Needle Rust (Coleosporium) Needles covered with numerous cream-color pustules (2-3 mm). Remove asters and other composite plants/weeds in the area.
RAPHIOLEPSIS Colletotrichum Leaf Spot Brown, circular-irregular shaped leaf spots. Sanitation. Protective sprays of Cleary's 3336.
RED CEDAR Armillaria Root Rot Dieback and total death of tree. Mushrooms or black thread-like structures may develop at base of tree and just under the bark, respectively. Sanitation.
ROSE Botrytis Blight Gray-brown irregular areas on flowers and leaves; gray mycelium and spores give spots/blotches a gray, cloudy appearance. Lower humidity levels; increase temperatures; prune out diseased plant parts; fungicides.
ROSE Black Spot (Diplocarpon) Black spots (1/8-1/4 inch diam. or 4-8 mm) with feathery margins. Follow a regular spray schedule; sanitation.
ROSE Downy Mildew (Pernospora) Irregular pale yellow spots on upper leaf surfaces; grayish-sometimes with thread-like growth-spots on lower leaf surfaces. Leaves eventually become brown, withered and drop. Sanitation. See APMH. Decrease humidity.
ROSE Powdery Mildew (Sphaerotheca) Whitish powdery growth on leaf surfaces; new growth may be distorted; leaves dry & turn yellow then brown; leaf drop. See APMH.
SHASTA DAISY Alternaria Leaf Spot Gray-brown, roughly circular spots. Sanitation. Cleary's 3336 or a benomyl fungicide should give some protective control.
SNAPDRAGON Pythium Root Rot Foliage wilt; roots brown and water-soaked. Sanitation. See APMH.
TULIP POPLAR Alternaria Leaf Spot Medium-brown, circular-irregular spots (1-2 cm or - inch long). Sanitation.
ALLSlime MoldWet-looking thin sheets of fungus material which may be green, reddish or brown in color. When the spore stage is present, plant material may be covered with a powdery coating of black, brown, red or yellow spores. Fungal sheets or masses may be physically removed; spore masses may be washed off with a strong stream of water; when conditions become dry, slime molds will disappear. These fungi do not cause damage to plants except for a shading effect.


March 18, 2000 - September 17, 2000:
Japan Flora 2000 'Communication Between Man and Nature'.
Awaji Island, Japan. See or Meg VanSchoorl at

June 1-3, 1999:
Mid-South Greenhouse Growers Conference.
Ramada Inn - Southwest Conference Center in Jackson, MS. More information will be available soon or you can contact Allen Owings, Extension Horticulturist at LSU.

July 8-12, 2000:
Ohio Florists' Association Short Course and Trade Show.
Greater Columbus Convention Center. Contact OFA at 614-487-1117; e-mail; web:

July 11-16, 2000:
American Nursery & Landscape Association Annual Convention.
Location TBA; contact ANLA at 202-789-2900;

July 16-19, 2000:
American Society for Horticultural Science 97th International Conference.
Disney Coronado Springs Resort, Orlando, FL. Contact ASHS at 703-836-4606; fax 703-836-2024; e-mail

August 3-6, 2000:
SNA 2000 - Southern Nurserymen's Association Researchers' Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636;

October 1-4, 2000:
Eastern Region International Plant Propagators' Society Annual Meeting.
Hyatt Regency Oak Brook, Chicago, IL. Contact Margot Bridgen, 26 Woodland Road, Storrs, CT 06268; phone 860-429-6818; e-mail

October 6-7, 2000:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
phone: 931-668-7322; fax: 931-668-9601; e-mail:, or

October 8-11, 2000:
Southern Region International Plant Propagators' Society.
Norfolk, VA. Contact David Morgan at 817-882-4148; fax 817-882-4121, SR IPPS, P.O. Box 1868, Ft. Worth, TX 76101; e-mail

January 27-31, 2001:
Southern Region American Society for Horticultural Science Annual Convention.
Fort Worth, TX. Contact Paul Smeal at 1107 Kentwood Drive, Blacksburg, VA 24060-5656, 540-552-4085; fax 540-953-0805, e-mail

August 2-5, 2001:
SNA 2001 - Southern Nurserymen's Association Researcher's Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636;

September 30 - October 3, 2001:
Eastern Region International Plant Propagators' Society Annual Meeting.
Lexington, KY. Contact Margot Bridgen, 26 Woodland Road, Storrs, CT 06268; phone 860-429-6818; e-mail

October 12-13, 2001:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
phone: 931-668-7322; fax: 931-668-9601; e-mail:, or

October 18-21, 2001:
Southern Region International Plant Propagators' Society.
Houston, TX. Contact David Morgan at 817-882-4148; fax: 817-882-4121; SR IPPS, P.O. Box 1868, Ft. Worth, TX 76101; e-mail:

October 11-12, 2002:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
phone: 931-668-7322; fax: 931-668-9601; e-mail:, or

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Letters to Bernice Fischman - 101 Funchess Hall - Auburn University, AL 36849.