Common Disease Problems
Anthracnose: This is a fungus disease that causes brown spots with purple edges on the leaves. The spots turn black in the center; leaves become yellow, dry and fall off. The fungus overwinters in diseased plant debris. Burpee Recommends: Avoid overhead watering which can spread the fungus spores. Keep a clean garden, remove and discard all diseased plant material. Use a mulch to prevent spores from splashing from the soil onto plants.
Bacterial Blight: This may occur mostly on the foliage causing small black spots or large brown spots. Some lesions may appear on twigs and may ooze in wet weather. Burpee Recommends: Prune only in dry conditions; do not water overhe; make sure plants are spaced such that they have good air circulation.
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Nectria Canker and Dieback: This fungus causes cankers and dieback of branches and twigs. It most often occurs in spring and fall on stressed trees. Sunken, discolored bark near wounds or at the base of branches are followed by reddish orange fruiting bodies and callus tissue. Burpee Recommends: Keep plants healthy and vigorous, and avoid damaging bark. Prune cankers in dry weather.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Leafhoppers: Leafhoppers cause injury to leaves and stunt growth. They also spread disease. Burpee Recommends: Remove plant debris. Use insecticidal soaps. Consult your Cooperative Extension Service for other insecticide recommendations.
Scale: Small bugs look like brown or tan bumps on the stems of plants. Scale may not have any apparent legs and may not move. Scale have a sucking mouth part. Scale may produce honeydew, so leaves and stems may be sticky. Scale can weaken the plant, causing it to grow very slowly. Burpee Recommends: Natural predators often keep populations in check. Completely spray the stems with insecticidal soap. For a severe infestation contact your local County Extension Service for recommendation for your area.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Can I grow this tree in a large container? Yes, in a very large container the tree will be smaller but it can be done.
Do I need to prune this tree? No, it has a multi-stemmed habit and does not require pruning except to remove dead wood.
Are magnolias pollinated by bees? No, they are in fact pollinated by beetles which are attracted to their fragrant flowers.
I only have a small garden, will ‘Black Tulip’ magnolia grow too large for it? No, this tree is perfect for small city gardens. It is multi-branched and makes a beautiful specimen growing only about 11-12 feet tall.
If I wanted to prune my tree for size and shape, when should I do this? Prune in late winter before the sap starts to rise as otherwise plants tend to bleed.