MAY 2003

Greetings from Auburn.

Ken left two days ago for three weeks in Australia to attend the International Plant Propagators Meeting. He has been very busy getting ready for that meeting as well as being engaged in many other projects. Those first two sentences explain why Ken's monthly comments are missing.

Please take note of the newly uploaded azalea pages. I was in Camp Hill a few weeks ago and hope to go again soon to take more photos of the azalea trial. The link to those pages is on our home page. Scroll down to the Azalea banner.

Have a wonderful spring. See you in June.


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.

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










Catnip may well be a new niche crop for growers. It is a perennial herb in the mint family (Lamiaceae) that has been used in cat toys and also for medicinal teas. Recent research with catnip has shown that an element in catnip was 10 times more effective at repelling mosquitoes than the commonly used and widely advertised DEET.

Until recently catnip seeds were the major source of plant material. Seeds from single plants are abundant but very small and difficult to work with. This research dealt with finding the most efficient way to propagate catnip plants. Researchers found that clonal propagation of catnip is the most reliable way to ensure uniform and genetically identical plants without having to harvest wild plants and deal with tiny seeds and unreliable results. Experiments were conducted to determine whether terminal, single-node or tip cuttings would be most effective. Cuttings were treated with indole-3-butyric acid (IBA) at different strengths and for differing amounts of time.

Among the cutting types it was determined that the length of the longest primary roots was greatest in cuttings that were harvested later in the propagation period.Conclusions were that terminal cuttings that were propagated for four weeks and grown for four weeks had less shoot dry weight and more root dry weight than the cuttings that were propagated for 2 or 3 weeks and grown for 5 or 6 weeks. The increased root dry mass seemed to account for long term growth by facilitating better nutrient and water uptake. Growers could expect good results if they use single-node cuttings during an 8-week production period by propagating cuttings for one or two weeks.

(from “Propagation of Catnip by Terminal and Single-node Cuttings” by Rolston St. Hilaire, published in Journal of Environmental Horticulture, March 2003).


Phlox is a perennial favorite in the nursery industry accounting for sales of over $7,000,000 in the United States (1998 Census of Horticultural Specialities). Preparing phlox for sale involves transplanting liners of creeping phlox into containers in the early fall so that plants will be ready the following spring. Unfortunately, optimal conditions for growing phlox are also optimal conditions for hairy bittercress (usually a winter annual in the wild) which germinates year-round in containers. Each plant can produce up to 5000 seeds. There are no preemergent herbicides currently on the market for bittercress control that are labeled for use on creeping phlox. Preemergent herbicides can damage herbaceous perennials. This study examined different herbicides at different strengths.

Creeping phlox varieties used in the study were 'Crimson Beauty', 'Emerald Blue' and 'Fort Hill'. Herbicides used were: Barricade 65WG, Dimension 1EC, Gallery 75 DF, Image 1.5 SL, Pennant 7.8 EC, Snapshot 2.5 TG, Surflan A.S., and Treflan HSP.

After conducting three experiments researchers found that isoxaben can be safely applied to creeping phlox for the preemergent control of bittercress. There is a difference, though, in the toxicity of the chemicals to phlox. Snapshot TG (granular formulation) applied to creeping phlox at rates of 1.38 to 2.75 kg ai/ha didn't injure the three creeping phlox varieties and did adequately control the bittercress. Gallery (the sprayabale formulation) applied at 0.56 kg ai/ha produced minor long-term injury in 'Crimson Beauty' and 'Fort Hill' varieties but didn't injure 'Emerald Blue' and didn't injure any variety when applied at rates of 0.28 kg/ai/ha. Applying Gallery at 0.14 kg ai/ha resulted in excellent bittercress control. No injury to creeping phlox was seen from Pennant and RegalKade applications at the stated label rates but the bittercress control was inadequate.

(from "Preemergent Bittercress Control in Creeping Phlox (Phlox subulata)" by Jeanne Briggs and Ted Whitwell, published in Journal of Environmental Horticulture, March 2003).


At the first annual meeting of the Alabama Invasive Plant Council in Montgomery a list of websites were shared. Sites of national interest follow:

Federal Laws and Lists of Invasive Species

US Forest Service Policy on Invasive Species


When ornamental shrubs are harvested at nurseries using the ball and burlap method there is a loss of organic matter to the remaining soil. This research investigated whether adding different kinds of compost would produce higher soil nutrient concentrations and induce higher plant nutrient uptake. Three kinds of compost (duck manure and sawdust; potato cull-sawdust-dairy manure; paper mill sludge-bark) were added to the topsoil to see how soil chemical properties would be impacted as well as shrub biomass production. Three types of shrubs were grown, Spirea japonicum ‘Gumball’, Juniper chinensis ‘Pfitzeriana’ and Berberis thunbergia ‘Atropurpurea’. The study took place over two growing seasons.

Soil organic matter when added improved soil nutrient concentrations in most cases. However, there were very measurable differences between the extent to which the three composts enriched the topsoil. And the three different types of shrubs responded somewhat differently. Barberry responded significantly to the compost application in the second growing season. The reason may be that barberry is considered intermediate in its growth rate whereas spirea is fast growing and juniper is slow growing. It is possible to speculate that intermediate growth rate species will benefit the most from short to intermediate improvements in soil fertility. Before using any of these composts it needs to be ascertained what the production goals are.

If soil is diminished by the topsoil removal for the balled and burlapped shrubs growers must be aware of the kind of impact this may have on their crop. It could result in impaired plant growth and the resultant lack of crop marketability. Usually improvements in soil chemical properties resulted in higher crop nutrient yields and in better crops.

(from “Compost Effects on Soil Chemical Properties and Field Nursery Production” by Ronald F. Gonzalez and Leslie R. Cooperband, published in the Journal of Environmental Horticulture, March 2003).


Chamaecyparis are extensively used as urban landscape plants. Planted in temperate-zones all over the world, they often adapt very poorly to adverse weather conditions, specifically extremes of heat or flooding. Since there are so many members of the Cupressaceae taxa, this research was performed to make a determination about which taxa would perform best in these weather conditions. Grafting the most adaptable and tolerant rootstocks could possibly enhance the performance of those that did not fare as well in this research.

Ten taxa of Chamaecyparis, Platycladus, Thuga spp. and x Cupressocyparis leylandii were grown in greenhouses and half of those were flooded and kept at two different temperatures. Unflooded plants had a 100% survival rate regardless of species and temperature. Chamaecyparis lawsoniana, Chamaecyparis thyoides, and Thuja occidentalis had 100% survival rate regardless of temperature. Chamaecyparis thyoides was very tolerant to flooding and temperature and might be a desirable understock but it is not yet determined whether long-term graft compatibility will work. x Cupressocyparis leylandii seemed to fare the worst in most of the tests.

(from "Evaluating Recovery of Cupressaceae Taxa After Flooding at Contrasting Temperatures" by Bradley T. Holland, Stuart L. Warren, and Thomas G. Ranney, published in the Journal of Environmental Horticulture March 2003).


The ALFA 2003 Horticulture Tour, August 9-15, 2003, will visit Pennsylvania nurseries and farms in and around Harrisburg, Penn State University, Lancaster County, Gettysburg and the Susquehanna Valley. The goal of the tour is to introduce producers to new ideas and methods so they will be able to make their operations more profitable. There will only be one bus so ALFA is asking that you make your reservation soon. Call Brian Hardin at 800-392-5705, Ext. 4217 for more information.


Jackie Mullen
Extension Plant Pathology Specialist

In March, we received 74 plant samples with 97% of the plants being ornamentals or turf. Cold damage in March caused some damage to landscape ornamentals in the central and northern sections of the state. Hollies and ligustrum with new growth were especially damaged. Some diseases seen included Pythium blight on bermuda; bacterial wilt on geranium; stunt nematode associated with poor growth of holly; Cercospora leaf spot on Indian hawthorn, ligustrum, and nandina; anthracnose on mountain laurel; crown gall on rose; Botrytis blight on peony, geranium, and holly ; Pythium seedling disease and root rot on coleus, lupin, petunia, and verbena; brown patch on St. Augustine grass; and take-all patch on St. Augustine grass and zoysia grass. Dieback of a rosemary sample was associated with very high levels of root-knot nematode. We also received a sample of a 'jelly fungus' Auricularia auricula (identified by Dr. G. Morgan-Jones) disease agent. (See below for more comments). The most important and most numerous samples received last month were geranium samples brought to us by state agricultural inspectors. See below for more information.

In late February, March, and early April our lab received a number of geranium samples from the Alabama Department of Agriculture and Industries inspectors. These samples were part of a national USDA-APHIS effort to contain an introduced new subspecies (Race 3 Biovar 2) of the bacterial wilt pathogen, Ralstonia solanacearum (R. s.). This new strain (Race 3 Biovar 2) of R. solanacearum was accidentally introduced to the U.S. in December on geranium cuttings from a Gold Smith, Inc. facility in Kenya. Cuttings were shipped in December to two greenhouse 'rooting stations' in Michigan and New Hampshire. From these rooting station greenhouses, plants were shipped all over the U.S. On February 14, USDA confirmed the presence of R. s. Race 3 Biovar 2 in plants from Michigan and New Hampshire.

All greenhouses that had received plant shipments from the contaminated rooting stations in Michigan and New Hampshire were identified, and USDA directed state departments of agriculture to collect symptomatic geranium samples from these greenhouse facilities and have them tested at their university or state plant diagnostic labs for the presence of Ralstonia solanacearum. All samples positive for the bacterial wilt bacteria were to be mailed to the USDA testing lab at Beltsville, MD where PCR (Polymerized Chain Reaction; a molecular technique identifying an organism by it's specific DNA characteristics) would determine the specific race and biovar present.

R. s. Race 1 Biovar 1 has been present in the U.S. for many years and causes bacterial wilt of solanaceous plants. Southern bacterial wilt of geranium was identified in North Carolina in 1981. R. s. Race 1 Biovar 1 was identified in Florida in geraniums in 2001. The R. s. Race 3 Biovar 2 was detected in Europe in the 1990s and is known to be especially damaging to Irish potatoes and other plants. It was introduced to the U.S. in 1999 and was reported in 2002 on geraniums in Wisconsin, South Dakota, New Jersey, New York, and Pennsylvania (V. S. Malek, USDA-APHIS-PPQ, ISPM. See pm/potato/ralstonia/ ).

This new outbreak in 2003 was traced back to the Kenya geranium cuttings (See , USDA, APHIS, PPQ Action Plan, February 27, 2003). R. solanacearum Race 3 is listed on the USDA Agricultural Bioterrorism Act of 2002, as a serious pathogen of potatoes and other plants. (USDA has indicated that this particular introduction into the U.S. is considered to be an accidental event, not linked to bioterrorism.) The host range of this pathogen (Race 3 Biovar 2) is mainly potato, tomato, other solanaceous plants (including weeds), geranium, stinging nettle, and other plants. Infected plants, contaminated irrigation or surface water, and contaminated soil or potting mixtures could be sources of inoculum. Early symptoms on geraniums involve leaf yellowing or leaf edge yellowing of lower leaves, possible leaf edge scorch of lower leaves. Later, wilt and dieback of the plant will occur. In advanced stages of disease, the cut lower stem placed into a jar of tepid water will produce a thin milky white 'thread' of ooze that will be visible in the water below the stem cut surface. Lengthwise slices of lower stem tissues will reveal dark brown discoloration of vascular and associated inner tissues. Other web sites providing additional information on this disease are: 1) University of Florida Pest Alert, T. Momal, J. Jones, S. Olson, ; Disease Alert: Ralstonia solanacearum by M. Daughtrey, Cornell University; Ralstonia solanacearum, Race 3 Biovar 2 found in U.S. Greenhouses by A. Hammer and K. Rane, Purdue University,; Update on Ralstonia Race 3, Biovar 2 from North Carolina State University, Plant Disease and Insect Clinic. (Much of the information in this paragraph was obtained from the Tim Momal web site.)

The early geranium samples we received were tested with preliminary culture work. Those plants that produced culture isolates questionable for R. s. were mailed to the Beltsville lab for further testing. By mid March our lab was able to obtain a serology (immunostrip test kit from Agdia, Inc.) test for rapid detection of the bacteria R. s. in plant tissue. Plants received mid March and later were tested and only sent on to Beltsville for Race and Biovar testing if we obtained positive serology identification of R. s. The Beltsville lab was overloaded with samples and it was not until April 10-14 when we received word (through the State Department of Agriculture & Industries) as to the results of samples sent. Some greenhouse facilities in Alabama (and many other states) were confirmed to have R. s. Race 3 Biovar 2 present in their geraniums. Dr. T. Johnson at the AL State Department of Agriculture and Industries explained that "USDA protocol states all geraniums that tested positive must be destroyed. Additionally, any plants that were shipped with the geraniums, any plants commingled with the geraniums, any plants within one meter of the geraniums in the greenhouse, and any plants in the greenhouse sitting below hanging geraniums must be destroyed."

The 'jelly fungus' (Auricularia auricula) was associated with turf grasses. The bodies were black, wet, gooey, and globular. These fungi are related to the mushroom group of fungi and do not cause plant disease. They develop in areas where moisture is available and where decaying plant material (usually buried wood) is present. Development of these fungus fruiting bodies is dependent on wet conditions so that when conditions dry out, these fungi typically become 'a black smudge'. Physical removal of these bodies and buried wood would help prevent continued fungal development.

March 2003 Plant Diseases Seen In The Auburn Plant Diagnostic Lab
BermudaPythium BlightLee
CleyeraEntomosporium Leaf SpotMacon
ColeusFusarium Root Rot*
ColeusPythium Root Rot *
FescueHelminthosporium Leaf SpotMacon
FescuePythium BlightMacon
GeraniumBacterial Wilt (Ralstonia solanacearum Race 3 Biovar 2)*
GeraniumBotrytis Leaf Spot*
GeraniumPythium Root Rot*
Holly Stunt Nematode Damage (Tylenchorhynchus)Montgomery
Holly, SavannahBotrytis Leaf BlightCullman
Indian HawthornCercospora Leaf Spot*
JuniperBotryosphaeria CankerMontgomery
LigustrumCercospora Leaf SpotLawrence
Lupin Fusarium Seedling DiseaseBarbour
Lupin Pythium Seedling DiseaseBarbour
Mountain LaurelAnthracnoseLee
NandinaCercospora Leaf Spot*
Oak Auricularia auricula (saprophyte) Montgomery
PeonyBotrytis BlightEscambia, Lee
PetuniaPythium Root Rot*
Rose Crown Gall (Agrobacterium tumefaciens)Houston
RosemaryRoot-Knot Nematode (Meloilodyne sp.)Autauga
St. AugustineBrown Patch (Rhizoctonia solani)Montgomery
St. AugustineTake-all Patch (Gaeumannomyces graminis var. graminis) Montgomery
VerbenaFusarium Root Rot*
VerbenaPythium Root Rot *
ZoysiaRing Nematode Problem (Criconemoides)Bullock
ZoysiaTake-all Patch (Gaeumannomyces graminis var. graminis) Bullock
*Counties are not reported for greenhouse and nursery samples.

J. Jacobi
Extension Plant Pathology Specialist

The lab received 70 samples for the month of March. Some of the samples received included: edema on camellia, Cercosporella needle blight on Leyland cypress, black root rot on petunia, and Asian ambrosia beetles on redbud.

Asian ambrosia beetles have caused problems again this spring. These small beetles (1/8 in. long) attack a wide range of hosts including crapemyrtle, oak, and redbud. Infestations can be identified by tooth pick-like strands of boring dust protruding up to a few inches from stems and branches of damaged plants. The insecticide permethrin (Astro and other formulations) has shown good efficacy against this pest. Follow label instructions carefully. More information on the identification and control of this pest can be found at the following web site: (

March 2003 Plant Diseases Seen In The Birmingham Plant Diagnostic Lab
AzaleaCercospora Leaf SpotJefferson
Basil Two-spotted Spider Mite *
BentgrassYellow Patch (Rhizoctonia cerealis)*
BoxwoodBoxwood LeafminerJefferson(2)
BoxwoodLow Soil pHJefferson
Camellia, CommonCold DamageJefferson
Camellia, CommonTea ScaleJefferson(3)
Camellia, SasanquaEdemaTuscaloosa
CleyeraCold DamageJefferson
Cypress, LeylandCercosporella Needle Blight Shelby
GardeniaCold DamageJefferson
Hydrangea, Oak LeafAnimal Damage (Vole)Jefferson
Indian HawthornEntomosporium Leaf SpotJefferson
MarigoldLow Media pH/Iron Deficiency *
Myrtle, WaxAnthracnose (Colletotrichum)Shelby
Myrtle, WaxCold DamageShelby
Myrtle, WaxSeptoria Leaf SpotJefferson
Palm, SagoMealybugsJefferson
ParsleyThrips *
PetuniaBlack Root Rot (Thielaviopsis)*
RedbudAsian Ambrosia BeetlesJefferson
RhododendronBotryosphaeria CankerJefferson
RhododendronCercospora Leaf SpotJefferson
RhododendronIron ChlorosisJefferson
Rose Phytophthora Root RotJefferson
Ryegrass, PerennialLeaf Spot (Drechslera)Jefferson
Ryegrass, PerennialPythium Blight Jefferson(2)
*Counties are not reported for greenhouse and nursery samples.


May 14, 2003:
Professional Grounds Management Society - Arboricultural Field Day.
Boone County Arboretum, Burlington, KY.
Contact Walter Bonvell, Xavier University, Physical Plant, 3800 Victory Parkway, Cincinnati, OH 45207-7111; 513.745.3151

June 5-7, 2003:
Native Plants in the Landscape Conference.
Millersville University, Millersville, PA.
Contact Department of Professional Training & Education, P.O. Box 1002, Millersville, PA 17551-0302, 717.872.3030, Fax 717.871.2022

June 18-21, 2003:
The 2003 International Master Gardener and Trade Show.
Northern Kentucky Convention Center, Covington, KY.
Contact: Bobbi Strangfeld, 513-946-8986, e-mail:; Marianne Riofrio, e-mail:, 614-292-8326; Sharon Bale, e-mail; Rick Durham, 859-257-7294, e-mail;

July 15 - 20, 2003:
ANLA Convention & Executive Learning Retreat.
Location TBA. Contact: ANLA, 202-789-2900; Fax, 202-789-1893.

July 30 - August 2, 2003:
SNA 2003- Southern Nursery Association Researcher’s Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA.
Contact SNA at 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636.

August 9 - 15, 2003:
2003 Horticulture Tour.
Contact Brian Hardin, Greenhouse, Nursery & Sod and Horticulture Divisions of ALFA
Phone: 334-288-3900; Fax 334-284-3957

August 15 - 19, 2003:
Garden Writers Association (GWA) 55th Annual Symposium.
Indian Lakes Resort, Chicago, IL.
Contact GWA at 10210 Leatherleaf Court, Manassas, VA 20111; 703.257.1032; Fax, 703.257.0213; e-mail

August 21-23, 2003:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail,;

September 11-13, 2003:
The Southern Plant Conference.
Charleston, SC.
Contact Danny Summers at SNA, 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636; e-mail,;

September 30 - October 4, 2003:
American Society for Horticultural Science Annual Meeting and 100th Anniversary.
Providence, RI.
Contact ASHS at 703-836-4606, Fax: 703-836-2024, E-mail:

October 3-4, 2003:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
phone: 931-668-7322; fax: 931-668-9601; e-mail:, or

October 5-8, 2003:
IPPS Southern Region NA.
San Antonio, TX.
Contact: Dr. David L. Morgan, 332 Warbler Drive, Bedford, TX 76021; phone 817-577-9272; e-mail,

October 8-11, 2003:
IPPS Western Region 44rd Annual Conference. Portland, OR.
Contact: Jim McConnell, Bailey Nurseries, Inc., 9855 NW Pike Road, Yamhill, OR 97148; 503-662-3244; e-mail,

October 22 - 25, 2003:
IPPS Eastern Region.
Portland, ME. Contact M. Bridgen, Margot Bridgen, IPPS Executive Secretary/Treasurer, 1700 North Parish Dr., Southold, NY 11971; 631.765.9638; Fax 631.765.9648; e-mail

July 29 - 31, 2004:
SNA 2004 - Southern Nursery Association Researcher’s Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA.
Contact: SNA 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636

August 26-28, 2004:
The Farwest Show. Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail,;

October 1-2, 2004:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
Contact Ann Halcomb, MTNA Exec. Secr., P.O. Box 822, McMinnville, TN 37111-0822; phone: 931-668-7322; fax: 931-668-9601; e-mail:, or

October 3-6, 2004:
IPPS Southern Region NA
Greenville/Spartanburg, S.C.
Contact: Dr. David L. Morgan, 332 Warbler Drive, Bedford, TX 76021; phone 817-577-9272; e-mail,

August 25-27, 2005:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail,

September TBA, 2005:
The Southern Plant Conference.
Louisville, Kentucky.
Contact: Matt Gardiner, KY Coordinator, 502-245-0238: e-mail,; or Betsie Taylor, KNLA Exec. Dir., 350 Village Drive, Frankfort, KY 40601; 502-848-0055 or 800-735-9791, Fax 502-848-0032 e-mail
or Danny Summers at SNA, 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636; e-mail,;

August 24-26, 2006:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail,

August 23-25, 2007:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401, 503-682-5089 x 2006; Fax, 503.682.5099; e-mail,

Send horticultural questions and comments to

Send questions and comments to

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