This is the season when American holly (Ilex opaca) reaches its peak popularity.
The use of its shiny evergreen spine-tipped leaves and red berries has long played an important role during the Christmas holidays.
It is the hardiest of the broadleaf evergreens grown in our area, a logical fact since this holly is a native of Stoddard County in Southeast Missouri.
Principal Growing Conditions For Hollies
Our area’s finest specimens of American holly are grown in full sun. When trees are planted in the shade, they tend to become somewhat leggy, with fewer leaves and light crops of berries.
The tree usually remains green in full sun and does not sunscald during winter or summer.
One of the principal requirements for a successful culture is using a thick mulch of pine needles, oak sawdust shavings, or similar materials placed over the root area.
Holly prefers acid soil with a pH of 5.0 to 6.0.
Dioecious American Holly Trees
American holly trees are dioecious. This means that their flowers are of two kinds, male (staminate) and female (pistillate), and these are borne on separate plants.
This is not a particularly unusual arrangement among trees, but those bearing bisexual flowers with both male and female parts together or separate on the same tree occur most commonly.
The female holly produces the berries, but male plants are needed to produce the pollen to fertilize the female flowers for fruit production.
Male flowers are usually produced more abundantly than female flowers.
Ordinarily, one healthy male plant, with the assistance of bees, will furnish sufficient pollen for about ten nearby female trees.
How To Distinguish Between The Two
At present, there is no way to tell a male from a female holly before they produce their flowers.
Horticulturists grow them from cuttings and can label their young plants correctly by simply depending on whether the cuttings used were taken from male or female trees.
In the spring, at blooming time, a close examination of the flowers of American holly will reveal whether the particular tree is male or female.
The female tree has a single flower on each small stem, but a few male flowers are found on a single stem.
A large shiny greenish knob is in the center of the female flower, and the four stamens around this pistil are small and withered.
The male flower has a small greenish knob in the center, but the four stamens are large and bear plump yellow anthers or pollen sacs at their tips.
The Burford holly (Ilex cornuta Burfordii) and some English Mollies bear fruits without male plants, but the seeds produced are not fertile and would not germinate.
Records at the Missouri Botanical Garden show that quite often, a few bisexual or perfect flowers occur on female holly plants, which produce berries with inviable seeds.
Most Popular Hollies
American holly plants grown from seeds vary in the size and shape of leaves and their glossiness. As a result, the fruit’s size, color, and abundance are also variable.
Horticulturists and other persons interested in these hollies have selected certain seedlings with merit.
Many seedlings have been named, increased by cuttings, and offered on the market. A few which have done well in our area are:
- Merry Christmas
- Old Heavy Berry
- Cardinal
- Croonenburg
- Howardi
- Fosteri
- East Palatka
Reasons Why American hollies Are Fruitless
If you happen to have an American holly that does not bear fruit, it is probably due to one of these reasons:
- Too young. Holly generally must be about five years old before fruiting.
- Male tree, which will never have berries.
- A female without a male is close enough for pollination.
- Occasionally, holly trees planted in different locations on the home grounds will not flower simultaneously, and pollination is impossible.
- Flowers might be damaged by a late freeze or other adverse weather conditions.
- Rainy weather, continuing during the blooming period, may prevent pollination and cut the crop of berries.
Protecting Your Hollies From Pest
This area’s most common insect pest on American holly is the holly leaf miner.
The larvae hatch from eggs deposited by the tiny female flies along the midrib on the underside of the leaf.
The larvae burrow into the leaf and tunnel tinder the epidermis, causing blistered white areas which ruin the holly, both in appearance and its use for decorative purposes.
The larvae change to pupae in early spring, and the adult flies emerge in May.
For control, spray with four tablespoons of 50% percent DDT wettable powder to three gallons of water. Apply two sprays at 10-day intervals, beginning May 10th.
44659 by Stanley R. Mclane