| [ounces of total N recommended (2 oz.) / %N(18)] * 100 = 11 ounces of 18-6-12 fertilizer |
Hardiness
Hardiness refers to the temperature extremes in which a plant will survive. Plants are classified by zones of low temperature tolerances to help you determine if a plant will withstand the average minimum temperatures in your area. Alabama ranges from Zone 7 in north Alabama to Zone 8 in south Alabama. Higher elevations in North Alabama can have low temperatures more typical of Zone 6, and areas of coastal Alabama can be classified as Zone 9. A plant designated as a Zone 8 plant would not tolerate some winters in a Zone 7 area. The hardiness of hollies varies among the species. They range from Zone 3 to Zone 9, but many are not hardy north of Zone 7. It is important to know the hardiness zone in your area to be sure that the holly you select is suitable.
Pruning
Small pruning cuts can be made any time of the year. Most pruning is best done when the holly is dormant. Pruning done in early autumn can prevent dormancy, and tender new growth--or the entire plant--can be killed during early freezes. Christmas is an excellent time to prune holly for decoration, and the plant can be shaped at the same time. Hollies can be sheared for hedges, but little pruning is required. Pruning should be used to train a leader or to remove dead wood. When shaping a holly, prune to a bud or lower branch. New growth might not appear if the entire branch is removed. Pruning is a matter of taste. Severe pruning (many hollies can be cut to within 6 inches of the ground and recover) is best done in late winter, prior to bud-break. This allows for limited time before regrowth and a shorter period of an unsightly pruned plant.
Insects And Pests
Holly is a plant that has developed many defenses against damaging pests. But, some insects have overcome these defenses.
Leafminers. Leafminers are black flies usually about 1/8 inch long. Each species of holly has a different species of leafminer. During the spring, leafminers emerge and attack the soft, new leaves of the holly. The female has an ovipositor at the tip of her abdomen. She uses it to puncture the leaves of the holly and lay eggs. Sap flows from the wound. The newly hatched larva then feed on the sap and tunnel into the leaves. Too many wounds cause improper development of the leaves.
Leaf feeders. Leaf feeders include caterpillars and weevils. Various types of caterpillars can be found on hollies. The oblique-banded leafroller can be a pest to American holly. These caterpillars roll up the leaves and live there. The saddleback caterpillar and the puss caterpillar will sting if they come in contact with human skin. Weevils can also be a problem. The black vine weevil, rough strawberry root weevil, two-banded Japanese weevil, and Fuller rose beetle feed on the leaves of holly.
Mites and scales. The southern red mite, the tenuipalpid mite, and the eriophyid mite are commonly found on holly, especially Japanese holly. These insects are small and difficult to see. Off-color, yellow foliage are often symptoms of these pests. Scale insects are another pest of holly. These insects attach themselves to the plant and pierce the leaves and twigs with their mouths in search of sap. The extra sap is excreted as honeydew and causes sooty mold. The black, sooty mold can be rubbed off with your finger. There are two types of scale insects: armored and soft scaled. Armored scales are protected by a hard, waxy secretion. These scales are the largest scale insects on holly. They are covered with a white, soft, gummy wax. The females die when they lay their eggs, and their bodies harden to give a protective covering to the eggs. Scales are difficult to control, and they are hard to detect because they feed on the underside of leaves.
Spittlebugs. The two-lined spittlebug can be a pest to holly, especially American Holly. They are less than 1/2 inch long, and their color ranges from tan to dark, reddish brown. Spittlebugs can be found in the eastern United States. They lay eggs in dying branches during the summer. The following spring, these eggs will hatch. The nymphs feed at the base of the holly. As they feed, a white, frothy spittle mass covers them. Eventually, they leave the spittle mass, molt, and become adults with wings. Then, they begin feeding on the sap from branches of the holly. This results in dead terminal growth and distortion of the stems and branches. To control the spittlebug, dead and dying branches should be pruned out to prevent eggs from being deposited on the holly.
Spraying without knowing the cause of the damage can often cause more harm than good. Beneficial and competing insects are also destroyed, causing an imbalance and potential buildup of harmful insects. Take insects and damaged leaves to your county Extension office for proper identification and control recommendations.
Diseases
Hollies are less susceptible to pests than most landscape plants and generally require little pesticide application. But, they can be affected by fungi, bacteria, nematodes, and viruses. Luckily, many of the holly diseases are not serious because the pathogens are not aggressive, although, if certain conditions exist, some diseases can occasionally be extremely serious.
There are two classes of disease: abiotic and biotic. Abiotic disease is caused by unfavorable environmental conditions. These diseases are non-pathogenic or non-infectious. Examples include winter injury, flooding, and drought. Biotic disease is caused by living organisms. These diseases are pathogenic or infectious. Examples include:
Fungi
* Root rot pathogens: General decline in plant growth, caused by excess moisture and unfavorable pH levels in the soil.
* Leaf spots: Small, brown spots on leaf; usually marked with dark borders.
Leaf spot on holly
* Blights: Young leaf, fruit, and twig tissue dies; occurs suddenly; spreads quickly.
* Mildews: Organisms growing on the surface of the leaf; serve as host for parasites.
* Sooty molds: Brown or black growth on plant; not serious for holly; detracts from the beauty of the plant.
Viruses
* Yellow leaf spot: Chlorotic spot on leaves; irregular leaf margins; spreads slowly; caused by tobacco ring spot virus.
Bacteria
* Bacterial leaf and twig blight: Found only in Massachusetts in 1957; leaves turn black and eventually fall off; heavily fertilized plants are more susceptible.
Diagnosing a disease is very important in determining the proper control measures to be used. The following steps should be used in diagnosing a disease:
1. Determine the affected parts of the plant.
2. Observe the disease occurrence pattern.
3. Look for susceptibility in other varieties.
4. Examine the trunk for possible damage.
5. Look for fungus signs.
6. Examine the roots.
7. Find out the history of the cultural practices on the affected plants and area maintenance (spraying, fertilizing, construction, wetland conditions, etc.).
Report your observations and take samples to your county Extension office for proper identification and recommendations. Once the cause of the disease has been determined, proper control measures can be taken. Often, problems can be eliminated with a change in cultural practices.
There are two types of disease control: cultural and chemical. Cultural controls involve changing the environment to favor plant growth (water plant more or less, increase soil aeration, etc.). Chemical controls use pesticides to cure the disease. Early treatment is important. Chemical regulations are not included here. Call your county Extension office for latest recommendations. Follow the label directions for application instructions and safety precautions.
Production And Commercial Operations
Commercial production of cut holly for sprays, floral designs, and wreaths began in the Pacific Northwest around 1890. Cuttings from trees and hedges were shipped to California. In 1891, a holly orchard was planted in Puyallup, Washington. It contained 40 trees. In 1898, the first holly was cut for sale. In 1948, Oregon produced approximately 750 acres of cut holly. In 1957, Oregon produced 1,380 acres of holly, while Washington produced 399 acres. In 1970, Oregon produced approximately 1,730 acres of holly. The distribution was 70 percent to New England; 20 percent to the Midwest; 5 percent to the South; and 5 percent to California. Currently, there is little commercial holly orcharding in the eastern United States.
Nursery production for landscape use is very significant in Zones 7 to 9 in the eastern United States. The production of holly for landscape use in the eastern United States rivals that of azaleas in dollar volume and numbers produced.
English and American hollies are the most common species for cutting, although English hollies are not suited for the heat in Alabama. Research is currently in progress to overcome this limitation and evaluate other hollies for orchard production and Christmas tree uses.
Pollination
Most nurseries sell hollies by sex or as named cultivars, and the berrying females are naturally sought after. A good nurseryman will try to guide the customer into the purchase of a male holly, to insure pollination and berry set on the female, if he feels it is necessary. But the term "holly" includes a surprisingly wide assortment of shrub and tree types of many different species and hybrids, both deciduous and evergreen. Thus, a legitimate question frequently arises: Which male hollies will pollinate which female hollies well enough to achieve a good dependable berry display? The following information will attempt to classify as many hollies as possible into cross-pollination groups.
In Alabama, some hollies begin blooming in March or earlier, while others blossom in April, May, and even June. On 'Nellie R. Stevens' and other similar cultivars, some open flowers have been observed between Thanksgiving and Christmas, but their main period of bloom is early spring. The small white (sometimes pink or yellow) flowers of holly may be overlooked by casual observers who may mistakenly insist that their hollies never bloom. Yet, they notice the bees swarming around. Honeybees work blooming hollies extensively for the nectar. The fragrance of holly flowers may be a rather faint to a heavy sweet honey aroma, drawing not only bees but other insects.
Most Old World and Asiatic hollies (English, Chinese, etc.) bloom on year-old wood, while most native hollies, except Yaupon (Ilex vomitoria), bloom on new wood, the first growth flush of the year. Regardless of where the flowers are borne, there are distinct differences between male and female flowers. Most male holly blossoms occur in axillary clusters. Tiny petals unfold to reveal tiny white filaments, each tipped with an anther (pollen sac). When the anther is ripe, it splits open to make the sticky, yellow pollen available to the first insect that comes along. Being male blossoms, the remnant female flower parts in the center never develop fully. They are non-functional, being much reduced in size. Female flowers are never produced as prolifically as the male flowers. Usually, only one or two occur per leaf axil. They open to show a single ovary, which looks like a miniature green "berry" in the center of the flower. There will be a poorly developed set of four stamens surrounding the ovary, but they are non-functional and produce no pollen.
A 10 x magnification hand lens permits a clear view of flower anatomy. The ovary carries a white, brown, or black spot at its summit, which is the stigma. When the stigma is receptive, you may see it glistening with stigmatic fluid. The style is non-existent; there is no long path for the pollen tube here as in lilies and other typical garden flowers.
As insects (primarily honeybees) clamber over the flowers, pollen is rubbed off onto the stigma. Viable pollen grains germinate, and the pollen tube grows down into the ovary where sexual fertilization occurs. This sends a chemical signal to the female blossom which then quickly proceeds to allow its petals and stamens to shrivel and dry. The immature, green fruit, enclosing the developing seed, proceeds to grow to full size during the growing season. When mature, the fruit changes to red, orange, yellow, white, or black, depending on species and cultivar. Unpollinated female flowers fall off the tree, except in those cultivars that are parthenocarpic, like Burford holly. They set fruit without benefit of pollination and can be loaded with berries when there is no male holly around for miles. It is incorrect to call them self-pollinating. Of course, cross-pollination increases berry set on parthenocarpic types, too. Parthenocarpically derived berries generally do not have viable seed.
The best pollinator for any female holly is generally a male of the same species. Some species have sufficiently evolved to erect sterility barriers between themselves and other species. In that case, pollination occurs only within the species. If a female is a hybrid, the male parent or a male sibling should be an effective pollinator. Certain groups of species and hybrids are closely enough related and will pollinate others within the group. This will result in a berry, even in many cases where the seed later aborts because of delayed sterility. Where viable seed is produced, and later germinates, the end result is a plant that is a hybrid between the two parent species or hybrids. This often frustrates taxonomic classification and is partly responsible for the confused or uncertain state of nomenclature in some Ilex taxa.
While holly males can be quite promiscuous, there are some practical limits to which species they can pollinate for a consistent production of a good berry crop. Appendix A, Table A-1, lists several groups of compatible holly species and hybrids that should be able to pollinate each other under garden conditions. Representative cultivars are listed for some of the entries. Rare species not likely to be encountered except by holly specialists are marked by an asterisk. Breeders might be able to get a few berries and seed in controlled crosses between groups. Males and females within a group bloom at the same time or at least overlap in bloom period and are compatible enough to set berries when cross-pollination occurs.
Some hollies have no compatibilities outside of their relative species. They include:
I. glabra (L.) A. Gray, inkberry holly.
I. pedunculosa Miquel, longstalk holly.
I. crenata Thunberg ex. J. A. Murray, Japanese holly.
I. vomitoria Aiton, yaupon holly.
Factors other than pollination can limit berry production. Spring frosts and freezes can injure holly blossoms or newly formed berries, causing them to drop. When mid-summer drought occurs, berries are the first organ on the holly plant to suffer. Thirsty berries develop wrinkles from water loss and soon thereafter may drop from the plant. Plants should be watered at the first sign of this type of stress to ensure a berry display in the autumn.
Biennial (alternate year) bearing may be a problem with certain hollies. A heavy berry crop may deplete the carbohydrate and nitrogen reserves so much that few blossom buds are produced for the next year. Leaves may take on a yellowish cast as reserves are exported to supply a heavy berry crop. During the off year, the plant builds up its reserves, sets a heavy crop of blossom buds, and the alternate cycle continues. Early thinning of the heavy berry crop, or additional fertilization, can help force more uniform annual bearing. Also, the energy drained off for berry production leaves less for the growth of the plant. Therefore, female plants may be smaller than male plants even though both are the same age and grow under the same conditions.
Since the holly bloom period covers several months, some species have completed blooming before others begin. Although rare, there are a few documented cases where certain males and females of the same species were observed to bloom at different times in the same planting. This may occur when northern and southern selections of a species enjoying a wide geographic distribution are brought together. Table A-2 shows how this applies to deciduous hollies at the Simpson Nursery in Indiana. Most of the northern selections of winterberry (Ilex verticillata) are nearly finished blooming before selections and seedlings of the southern types begin. The same blooming sequence in Table A-2, although adjusted for earlier dates, may apply in southern states, but testing is needed.
Blooming dates can only be approximate as there are so many variables from year to year. A few days of weather unfavorable for pollination can extend the blooming period for cultivars in bloom at the time. A few warm, sunny days can result in maximum insect activity and shorten the bloom period for the cultivars then open. Older plants bloom earlier than younger, vigorous plants. Limbs near the ground may bloom early. The start of the blooming period is a question. Is it when the first blossom opens, or when a fair number are open? Technically, the date of the first flower is significant. However, the peak of flowering is more significant to the volume of fruit. Dates listed in Table A-2 signify when enough flowers were open to attract insects.
Holly pollen from a single male flower does not remain available or viable for very long. A male flower often opens in the morning, sheds pollen in mid-day, and sheds its petals by the following morning. The higher the temperature, the shorter the flowering period. Male plants can be spotted by the petals lying on the ground. Female flowers, which have a receptive stigma for only a few days, can stay open for a week if unpollinated. Petals quickly shrivel with pollination. Fortunately, not all flowers on a plant open at exactly the same time. But, there is only a short overlap in bloom period of males and females, and if that period is unfavorable for insect activity, berry set may be quite limited.
Distance between male and female holly plants is a factor. Commercial orchards, which produce cut branches of berried holly for the Christmas trade, set out one male for every fifteen female trees. When the spacing is 25 feet between trees in a square grid pattern, that works out so that every female is no farther than 71 feet from a male. In the landscape, pollination and berry set would usually occur with males and females separated up to 1/8 mile (660 feet), while 1 mile would be problematical, and 3 miles would be very unusual but possible.
It really comes down to how far the bees range in your locality and how actively they are working the flowers. This is a judgment call depending on how far bees fly to work plants of the same kind. For the bee, it involves balancing an energy equation: How much energy has to be expended to gather a nectar source containing x amount of sugar? Energy-rich nectar sources close to the hive are worked first. Cool, cloudy, rainy weather diminishes bee activity and subsequent heaviness of berry set. Heavy rain can also wash pollen away.
In summary, pollination and berry set depends on three things: overlapping time of bloom of males and females, compatibility between species, and favorable weather conditions, assuming bees, primarily honey bees, and other insects will be present in the general locality.
Propagation
Holly can be propagated by seed, cuttings, and grafting. Propagation by cuttings is the most preferred method, since cultivars will not come true from seed.
Seed
The fruit of the holly contains "seeds" or pyrenes that must be removed from the mealy flesh. The seed coat is virtually impermeable, and the embryo is immature. The result is a 2- to 3-year germination period. For the best results, plant the seeds in a flat, moisten them and place them in a plastic bag; leave the flat on a shelf in a room with a temperature ranging from 60° to 80°F, and wait for the seedlings to emerge. Then, remove the plastic and place the seedlings in normal conditions.
Cuttings
Propagation by cuttings is the most popular method. But, all hollies do not root easily. On the other hand, Chinese and Japanese holly root very well. The best time to take cuttings for most evergreen hollies is from August to November. Deciduous soft-wood cuttings should be taken from June to July. Take the cuttings from terminal branches, where the wood is firm. For best results, wound both sides of the stem (only to the cambium layer) and apply rooting hormone. A well-drained medium of peat:perlite or pine bark can be used. A bottom temperature should be maintained between 70° to 75°F. Misting is also recommended. Keeping unheated cold frames at high humidity can produce rooted cuttings of many species. Time for rooting will take longer than more sophisticated systems. Maintaining high humidity is very important during the rooting process. High-humidity rooting chambers can be made by filling a flower pot with a potting medium and covering with a plastic bag supported by a coat hanger. Put in the shade while rooting. If the above steps are followed, roots should appear within 4 to 8 weeks, and the rooted cuttings can be transplanted with success in 8 to 16 weeks.
Grafting
Propagation by grafting is not a common practice, but it has been successful where root rot was a problem. Grafting selected cultivars of American holly onto American holly seedlings was common practice for many years prior to the perfection of cutting techniques. 'Burfordii' has been used as an understock for several hollies, especially English holly. Unfortunately, these grafted hollies can be difficult to transplant. Some of the "blue hollies" are currently being tested on 'Nellie R. Stevens' root stock to help reduce susceptibility to root rot in southern states.
Container Production
Holly has become a major crop for many nurseries and is shipped all over the United States. These nurseries propagate holly from cuttings. Eventually, they are transplanted to larger containers. Container size usually ranges from 1-, 2-, or 3-gallon plants but varies depending on the market. Hollies can now be found in 20- to 200-gallon containers for the "instant landscape" look. Container medium is usually composed of sand:peat:pine bark (1:1:4). Slow-release fertilizers are added to supply nitrogen, phosphorus, and potassium, and the other required major and minor elements. Soluble fertilizer can also be injected into the irrigation system to maintain nutrient balance. Full season slow release fertilizers are now available that include all the nutrients required for a season's growth. For information on how to grow container plants, ask your county Extension office for Circular ANR-690, "Starting A Container Nursery."
Conclusion
As you can see, there are many reasons for the use of holly as a popular shrub and ornamental tree. There are many species of holly, resulting in plants with a variety of shapes and sizes. Hollies are classified as evergreen or deciduous, and their leaves may or may not contain spines. The fruit is found only on the female, and the fruit color ranges from red, orange, or yellow to black or white.
Although hollies can be found worldwide, 98 percent of the cultivated species originated in Europe, China, Japan, or North America. The use of holly for indoor decoration or for landscape purposes is the result of traditions from many cultures spanning many centuries. Today, holly is the backbone of our landscapes in the Southeast.
Sources Used In This Publication
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Table A-1. Holly species And Hybrids Useful In Cross-Pollination.
The following groups of holly species and hybrids will cross pollinate each other for good berry production under garden conditions. A partial list of reprersentative cultivars is included. Any male within a given group should pollinate any female within that group, but not females in other groups. Taxonomic authority is listed immediately following the scientific name. Parentage of hybrids is given in [square] brackets. Common names are given when known. Cultivar names are enclosed in 'single' quotation marks.
| TYPE OF HOLLY | CULTIVARS |
| GROUP 1 |
|---|
I. x altaclarensis (Loudon)
Dallimore
[I. aquifolium x I. perado]
Highclere Holly |
'Camelliifolia'
'Golden King'
'James G. Esson'
'Lawsoniana'
'Wilsonii' |
I. aquifolium L.
English Holly |
'Aureo-marginata'
'Argentea-marginata'
'Balkans'
'Boulder Creek'
'Ciliata Major'
'Ferox' (Male)
'Little Bull' (Male)
'San Gabriel'
'Sparkler'
Many others |
| I. aquifolium x I. cornuta | 'Nellie R. Stevens'
'Edward J. Stevens' (Male) |
| I. x aquipernyi Gable | 'Aquipern'
'Brilliant'
'San Jose' |
*I. x beanii Rehder
[I. aquifolium x I. dipyrena] |
| I. ciliospinosa Loesener |
| I. cornuta x I. ciliospinosa | 'Albert Close'
'William Cowgill'
'Howard Dorsett'
'Edward Goucher'
'Harry Gunning' |
I. cornuta Lindley & Paxton
Chinese Holly | 'Anicet Delcambre'
('Needlepoint')
'Berries Jubilee'
'Burfordii'
'Cajun Gold'
'Carissa'
'Dazzler'
'D'Or'
'Dwarf Burford'
'O. Spring'
'Rotunda'
'Shangri-La'
'Shiu-Ying'
'Willowleaf' |
| I. cornuta x I. pernyi | 'Doctor Kassab'
'John T. Morris' (Male)
'Lydia Morris' |
| I. cornuta x I. Latifolia | 'Emily Bruner'
'Ginny Bruner'
'Bob Bruner'
'James Swan' (Male) |
| *I. dipyrena Wallich |
| *I. fargesii Franchet |
I. integra Thunberg ex J.A. Murray
Nepal Holly |
I. x koehneana Loesener
[I. aquifolium x I. latifolia]
Koehne Holly | 'Hohman'
'Jade'
'Lassie'
'Ruby'
'Wirt L. Winn' |
I. latifolia Thunberg ex J.A. Murray
Lusterleaf Holly |
| *I. leucoclada (Maximowicz) Makino |
I. x meserveae S.Y. Hu
(I. rugosa x I. aquifolium) | 'Blue Angel'
'Blue Boy' (Male)
'Blue Girl'
'Blue Maid'
'Blue Prince' (Male)
'Blue Princess'
'Blue Stallion' (Male)
|
I. perado Aiton
Madeira Holly |
I. pernyi Franchet
Perny Holly |
I. rugosa F.Schmidt
Prostrate Holly |
| I. spinigera (Loesener) Loesener |
I. x wandoensis in ed.
[I. cornuta x I. integra] |
| GROUP 2 |
|---|
I. x attenuata Ashe
[I. cassine x I. opaca] | 'Alagold'
'Big John' (Male)
'Blazer'
'East Palatka'
'Foster #2' (also #1, #3,
#4 (Male), #5)
'Hume #2'
'Savannah' |
I. cassine L.
Dahoon Holly |
| *I. cumulicola (Ashe) Ashe |
| I. myrtifolia Walter |
| I. myrtifolia x I. opaca | 'Oriole'
'Tanager' |
I. opaca Aiton
American Holly | 'Cardinal'
'Canary'
'Dan Fenton'
'Farage'
'Jersey Knight' (Male)
'Jersey Princess'
'Miss Helen'
'Old Heavy Berry'
'Wyetta'
Many others |
| GROUP 3 |
|---|
I. serrata Thunberg ex J.A. Murray
Finetooth Holly
Japanese Winterberry | 'Christmas Cheer'
'Leucocarpa'
'Xanthocarpa' |
| I. serrata x I. verticillata | 'Apollo'
'Autumn Glow'
'Bonfire'
'Harvest Red'
'Hopewell Myte'
'Raritan Chief'
'Sparkleberry' |
I. verticillata (L.) Gray
Winterberry, Michigan Holly | 'Aurantiaca'
'Afterglow'
'Bright Horizon'
'Cacapon'
'Christmas Gem'
'Earlibright'
'Fairfax'
'Hopperton'
'Jackson'
'Maryland Beauty'
'Mill Creek'
'Red Sprite'
'Shaver'
'Short Cake'
'Stoplight'
'Sunset'
'Winter Gold'
'Winter Red'
'Xanthocarpa' |
| Note: Northern selections of I. verticillata may not be pollinated by males of the southern selections because blooming periods may not overlap. Most northern selections do overlap with the bloom of I. serrata and its hybrids. See Table A-2. |
| GROUP 4 |
|---|
I. decidua Walter
Possumhaw Holly | 'Byer's Golden'
'Council Fire'
'Pocahontas'
'Red Cascade'
'Red Escort'
'Reed'
'Sentry'
'Sundance'
'Warren Red' |
| Note: Female I. decidua will usually set fruit well if male I. opaca are nearby as the bloom period of many cultivars overlap. See Table A-2. |
*I. longipes Chapman
Georgia Holly |
* Rare and not likely to be encountered except by holly specialists.
Table A-2. Order Of Bloom Dates For Deciduous Hollies And American Holly At Simpson Nursery, Vincennes, Indiana, 1979 and 1990.*
| Type Of Holly | 1979 | 1990 |
| I. decidua (early) |
May 13 - 27 |
May 5 - 23 |
| I. decidua (late) |
May 17 - 30 |
. |
| I. opaca, most cultivars | May 19 - 30 |
May 9 - 28 |
I. serrata
(well pollinated) | . | June 5 - 13 |
I. serrata x verticillata
hybrids | . | . |
| 'Autumn Glow' | . | June 3-15 |
| 'Harvest Red' | . | June 3 - 15 |
| 'Raritan Chief' (Male) | . | June 3 - 15 |
| 'Bonfire' | . | June 8 - 16 |
| 'Apollo' (Male) | . | June 12 - 18 |
| 'Sparkleberry' | . | June 12 - 18 |
I. verticillata
(northern types) | May 30 - June 6 | . |
| Dwarf male selections | May 30 - June 8 | June 1 - 12 |
| 'Aurantiaca' | May 30 - June 4 | June 1 - 10 |
| 'Red Sprite' | . | June 3 - 15 |
| 'Stoplight | . | June 3 - 12 |
| 'Short Cake' | . | June 3 - 12 |
| 'Tiasquam' | . | June 3 - 12 |
| 'Maryland Beauty' | . | June 4 - 12 |
| 'Afterglow' | June 4 - 14 | June 6 - 13 |
| 'Shaver' | June 6 - 15 | June 7 - 18 |
| 'Jackson' (Male) | June 6 - 15 | . |
| 'Cacapon' | June 6 - 15 | June 9 - 17 |
| 'Fairfax' | June 9 - 18 | . |
| 'Quitsa' | . | June 11 - 17 |
| 'Sparkleberry' | . | June 12 - 18 |
| I. verticillata | . | . |
| (southern types) | June 11 - 28 | . |
| 'Sunset' | . | June 14 - 19 |
| 'Winter Red' | June 12 - 28 | June 14 - 21 |
| 'Winter Gold' | . | June 14 - 21 |
| males for 'Winter Red' | June 12 - 28 | June 14 - 23 |
| southern type seedlings | June 19 - July 3 | June 19 - July 4 |
| *Adapted from published and unpublished information of Robert C. Simpson, a longtime nursery grower of deciduous hollies. Bloom dates will be 2-3 weeks earlier as you move south to Tennessee and Alabama. This is offered as a guide only from observations in Indiana. Flowering will vary with the provenance of the seeding source and the location of the hollies. |
| NOTE: I. opaca males will pollinate I. decidua females. |
| Zone |
Garden And Address |
Zone |
Garden And Address |
| 4b | Denver Botanic Gardens
909 York Street
Denver, CO 80206 |
5b |
The Holden Arboretum
9500 Sperry Road
Mentor, OH 44060 |
| 5b | The Dawes Arboretum
7770 Jacksontown Road, SE
Newark, OH 43055 |
5b |
Taylor University Arboretum
Upland, IN 46989 |
| 5b |
The Chicago Botanical Garden
P.O. Box 400
Glencoe, IL 60022 |
5b | Secrest Arboretum
Ohio State University
Wooster, OH 44691 |
| 6a | Bernheim Forest Arboretum
Clermont, KY 40110 |
6a | Department of Botany
Porter Hall
Ohio University
Athens, OH 45701 |
| 6a | Highland Botanical Garden
180 Reservoir Avenue
Rochester, NY 14620 |
6a | Missouri Botanical Garden
2345 Tower Grove Road
P.O. Box 299
St. Louis, MO 63110 |
| 7a | The Tyler Arboretum
515 Painter Road
P.O. Box 216
Lima, PA 19037 |
7a | Morris Arboretum
University of Pennsylvania
9414 Meadowbrook Avenue
Philadelphia, PA 19118 |
| 7a | Planting Fields Arboretum
Planting Fields Research
Oyster Bay, Long Island, NY 11771 |
7a | Holly Haven Hybrids
136 Sanwood Road
Knoxville, TN 37923 |
| 7a | The Tyler Arboretum
515 Painter Road
P.O. Box 216
Lima, PA 19037 |
7a | The Scott Arboretum
Swarthmore College
Swarthmore, PA 19711 |
| 7a | University of Delaware
Department of Plant Science
Newark, DE 19717-1303 |
7a | University of Tennessee Arboretum
901 Kerr Hollow Road
Oak Ridge, TN 37830 |
| 7a | U.S. National Arboretum
3501 New York Avenue, N.E.
Washington, DC 20002 |
7b | NC State University Arboretum
Department of Horticulture, NCSU
Box 7609
Raleigh, NC 27695-7609 |
| 7b | Ebersole Holly Garden, S.C.C.
2200 Airport Road
Pinehurst, NC 28374 |
7b | Callaway Gardens
Pine Mountain, GA 31822 |
| 7b | University of Alabama
338 Thomas Street
Box 870176
Tuscaloosa, AL 35487-0176 |
7b | Botanical Garden
Clemson University
Clemson, SC 29634-0375 |
| 8b | University of British Columbia
Botanical Garden
6501 North West Marine Drive
Vancouver, BC V6T 1W5
CANADA |
8b | Washington Park Arboretum
University of Washington
Seattle, WA 98195 |
| 8b | Vandusen Botanical Garden
5251 Oak Street
Vancouver, BC V6M 4H1
CANADA |
| Bokrijk Arboretum
Stationstraat 70, 3530 Houthalen
BELGIUM | |
Acknowledgments
We respectfully acknowledge the professional advice of Mr. Gene K. Eisenbeiss, horticulturist at the U.S. National Arboretum, Washington, D.C., for reviewing the text and verifying the nomenclature and taxonomic authorities listed. We further acknowledge the expertise of Mr. Robert Simpson and Mr. Harold Elmore, who made many helpful suggestions on pollination. And, we would like to extend a special thank you to Ms. E. Elizabeth Kassab, Mr. Lloyd Hahn, Mr. Carl W. Suk, and Mr. Cliff Dickinson, for their review of the text.
