Although having a female plant is desirable in the case of your
holly, there are other plants that produce messy or smelly fruits.
In those cases, male plants are preferred.
For example, female
ginkgo trees produce fruits that have a putrid smell, and female
Kentucky coffee trees produce sharp, messy pods that are a nuisance
to clean up.
Is it a Male or Female Holly?
When your holly blooms next spring, examine the blossoms. Female
hollies have a small green fruit (actually the ovary) in the center
of the flower; male hollies have only stamens, the structures that
produce pollen. Once you figure out the sex of your holly, you will
have to buy it a mate of the opposite sex. You should shop for your
holly’s mate when it is in bloom so that you can examine the flowers
rather than relying on the plant tag at the nursery.
Tags can get
switched, and it would be disappointing to bring home the wrong
holly. It is important that your holly and its prospective mate are
the same species – Ilex opaca – and are in bloom at the same time.
They should be planted in reasonable proximity to each other, but do
not have to be side-by-side because holly flowers are pollinated by
different species of bees, including honeybees.
Red holly berries
The damage to the foliage is probably caused by the native holly
leafminer (Phytomyza ilicicola), a small insect that lays its eggs
between the layers of the newly emerging leaves. The larvae hatch
out and develop and feed inside the leaf, creating the damage you
are seeing. To protect your holly against this damage, make an
insecticide application as new growth begins in May.
BioNeem (azadirachtin); Sevin (carbaryl); pyrethrins and piperonyl
butoxide; and Captain Jack’s Deadbug Brew (spinosad) are all labeled
to control leaf miner on American holly.
Avoid spraying when the hollies are blooming because bees and other
pollinators will be working the flowers and could be killed by the
application. Although this damage is unsightly, it is not life
threatening. You may opt to live with it.
Soil Tests & Fertilization
While fertilizing will not help produce fruit, it is not a bad idea
to collect a soil sample and submit it to Penn State’s Agricultural
Analytical Laboratory to make sure that the soil pH and fertility
levels are in the preferred range for hollies. It is difficult to
guess what nutrients or pH adjustments may be needed, so it is best
to fertilize on the basis of soil test results.
Soil test kits are available at your local Penn State Extension
office. In Allegheny County, kits for home gardeners come with
complete instructions for taking a representative sample and
understanding your soil test results.
Holly Berries and
Blotches on leaves? Holly Leafminer
Landscaping Steep Banks