How to Grow B & O Holly (Ilex opaca)

Variety: Ilex opaca

Family: Aquifoliaceae
Cultivar: B & O
Zones: 5 to 10
AHS Heat Zone: Not defined for this plant
Soil Type: Some sand to loam
Soil pH: 5.5 to 7
Sunlight: Sun to full sun
Watering: Normal to moist
Fertilizer: Shrub and tree fertilizer

Availability: Sold as live, potted plants.

When to plant: Plant the B & 0 Holly at any time during the growing season when there is no danger of frost.

Planting Method
CONTAINER: Dig a planting hole twice the size of the root ball and as deep as the soil in the container. Center the B & 0 Holly in the planting hole and backfill with soil. Create a water ring around the perimeter of the planting hole. The water ring will help divert water to the outside roots and will encourage proper root growth and nourishment. Mulch with at least three inches of compost or pulverized bark. Water well.

BALLED AND BURLAPED: Dig a planting hole three times the size of the root ball and as deep as the root ball. Scarify the sides of the planting hole with a pitchfork or shovel. If the burlap is synthetic, remove and discard it, as synthetic burlap does not decompose. Center the B & 0 Holly in the planting hole. Remove any staples or ties holding organic burlap on the plant. Fold the top of the burlap down far enough into the planting hole so that it is completely covered when you backfill. Backfill with soil. Create a water ring around the perimeter of the planting hole. Mulch with at least three inches of compost or pulverized bark. Water well.

BARE ROOT: Soak the B & 0 Holly's roots for at least eight hours to ensure proper hydration. Dig a planting hole as wide as the spread-out roots and as deep as the discoloration on the trunk that shows how deep the holly was previously planted. Center the holly in the planting hole and backfill with soil. Create a water ring around the perimeter of the planting hole. The water ring will help divert water to the outside roots and will encourage proper root growth and nourishment. Mulch with at least 3 inches of compost or pulverized bark and water well.

Watering: Water with at least an inch of water per week. The soil should be kept moist to a depth of 18 inches. Water again when the top six to seven inches of soil dries out. If you have a problem with excess standing water, create a French drain to help divert excess water to another part of the garden or yard.

Fertilizing: Fertilize the B & 0 Holly with shrub and tree fertilizer once every three years in the spring. If a soil test shows low or missing nutrients, use a nutrient-specific fertilizer instead of an all-purpose fertilizer. If you use organic fertilizer, such as fish emulsion, be sure to follow the instructions on the package, as different brands have different ingredients and strengths.

Production: B & 0 Holly is a low-maintenance evergreen tree that produces small, dark-green leaves and flowers in shades of cream and white. It also produces berries. This plant is poisonous.

Diseases

• Anthracnose: A fungus causes anthracnose. It can cause defoliation. Signs include sunken patches on foliage and fruit. Foliage and fruit may also have a gray-brown color to it, or have pinkish-tan, slimy spore masses. For prevention, do not over-water plants. Keep plants staked and allow them to grow on a trellis to help with air flow. Always remove and discard infected plants. Anthracnose can be controlled with a fungicide.
• Leaf Spots: Bacteria or fungi cause brown or black spots on leaves. The leaf spots have no particular shape, but the edges look yellow. People, rain and insects spread leaf spots. When the plant is dry, remove the infected leaves. Be sure to keep the plant pruned properly, and clean up any dropped leaves under the plant. Water plants from below, taking care to keep the foliage dry. Leaf spots can also be controlled with fungicide.
• Powdery Mildew: Powdery mildew is a fungus that usually affects plants that have low air circulation and inadequate light. It is a bigger problem in the early spring and fall months, when the temperatures swing from high during the day to low at night, especially in zones with a lot of humidity. Powdery mildew forms a white or gray coating on the top of the leaves, making them turn yellow, curl up and drop off. It also causes stunted fruit that drops early. To control powdery mildew, decrease watering, use a fertilizer that is low in nitrogen and keep water off the foliage. Apply fungicides as directed.
• Pythium and Phytophtora Root Rot: Pythium and phytophtora root rot attack a plant if there are fungal spores in the soil and the plant is overwatered, creating a high moisture level. Roots turn black and break. Leaves yellow and fall off, usually from the bottom up. Contaminated water or soil mix is the usual cause of root rot. To control this disease, remove infected plants, make sure the soil is well-drained and do not overwater or overfertilize plants. There is no chemical treatment for root rot.
• Rhizactonia Root and Stem Rot: Rhizoctonia is found in a lot of soils. It enters the plant through the roots and causes it to wilt as it travels up the stems. The lower leaves will wilt first. If you think your plant has this problem, decrease watering. If all of the leaves are wilted, discard the plant and clean the pot with a bleach-and-water mixture. Fungicides will also control Rhizactonia.
• Sooty Mold: Sooty mold is a black, sticky fungus that feeds on honeydew put out by aphids, mealybugs and scale insects. It attracts ants. You can get rid of it by keeping the pests out of your plants and by washing away with a sprayer. Though it is a fungus, fungicides may not control it. Be sure to keep the plant properly pruned to help with sooty mold.

Pests

• Aphids: The aphid is a small insect that forms clusters on seedlings and new plant growth. It's pear-shaped body ranges from 1/16- to 3/8-inch long. Aphids spread quickly, feeding on plant juices, which weakens the plant. Signs of infection include honeydew and sooty mold on plants, curling leaves, stunted growth and yellowing of foliage. Remove infected plant matter and keep the garden weed-free. Do not use high-nitrogen fertilizer, as this promotes aphids. If you have a light infestation, you can spray the aphids off the plant with water, then apply insecticidal soaps or pesticides. Aphids will develop a resistance to pesticides, so use them sparingly and as a last resort. If you do not wish to use insecticides or pesticides, you can introduce natural enemies of the aphid, such as lacewings, parasitic wasps or pirate bugs.
• Fungus Gnats: Fungus gnats (Shoreflies) are the size of fruit flies. They are usually found on the surface of the soil. They like wet conditions, hardwood bark and manure, so watch for this pest if you use any type of mulch. The larvae cause root damage. Adults transmit plant disease, but the adults are generally not responsible for direct damage to the plant. To control fungus gnats, do not over water and spray an insecticide on the larvae. Adults can also be controlled with insecticides.
• Leaf Miners: Leaf miners are the larvae of different bugs, including moths, flies and beetles. A leaf miner creates a tunnel between the upper and lower surface of a leaf. They are attracted to vegetables and ornamental plants. To control leaf miners, keep the area well weeded, introduce parasitic wasps and remove and discard infected leaves. Some insecticides may kill leaf miners.
• Maggots: Maggots are the larvae of dark gray flies, a fly that looks much like the common housefly. The maggots chew the root hairs off plants and will burrow through roots, especially edible roots such as onions and garlic. Introduce nematodes and rotate crops to control maggots. Infected plants should be removed and destroyed.
• Mealybugs: Mealybugs are covered with a white wax and feed on plants by inserting stylets into the plant. They secrete honeydew, which creates sooty mold and attracts ants. Eggs are laid inside a cotton-type pouch and hatch in 7 to 10 days. The adults live about 30 days, and can lay several hundred eggs. Control mealybugs with an insecticidal soap or pesticides.
• Scale Insects: The 1/8-inch-long scale insect attaches itself to the leaves and stems of plants. While the males have wings, the females do not, and spend their lives attached to the plant, sucking out juices with their piercing mouth parts. The scale insect excretes honeydew, which causes sooty mold that attracts ants. Cut any infected leaves off the plants. If the stems are also infected, you may have to dispose of the entire plant. You may be able to control them with insecticidal soaps or pesticides. You can also introduce parasitic wasps to your garden, as they are the scale insect's natural enemies. Lady beetles are also natural enemies.
• Whiteflies: Whiteflies are less than 1/8 of an inch long, with white wings and yellow bodies. Their eggs hatch in 8 to 11 days. They have piercing mouthparts and suck the juices from plants, which causes stunted growth and yellow leaves. They can be controlled with pesticides, but in order for them to be effective, the underside of the leaves must be treated. Parasitic wasps and lady beetles can be used for outdoor control.

Cleanup: Prune B & 0 Holly in the spring and throughout the growing season for dead and decaying plant matter. Pinch the stem tips to encourage foliage growth.

Warning: B & O Holly is susceptible to blight. Blights are caused by various fungi and bacteria. There are many different types of blight, and each type has its own method of control. Help prevent blight from attacking this plant by keeping it disease and pest-free.