Common Disease Problems
Alternaria Leaf Spot: Small, round reddish brown spots with white to grey centers form on the upper surface of the leaves and along the midrib. The lesions may encircle the stems and cause wilt. This disease is worse in warm, wet or very humid weather. Burpee Recommends: Avoid getting water on the foliage. Remove infected plant parts and do not work around wet plants. Provide plenty of air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
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.
Downy Mildew: This fungus causes whitish grey patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Fusarium Wilt: The first symptom of fusarium is the appearance of a few yellow leaves or a slight drooping of the lower leaves. Caused by a soil-borne fungus, the fungus enters through the roots and passes up into the stem producing toxic substances. Burpee Recommends: Destroy affected plants at the first sign of fusarium; rotate crops.
Virus (Various causes): The most characteristic sign of virus is tight and dark green mottling of the leaves. Burpee Recommends: Avoid handling plants. Destroy diseased plants and the plants on either side. Never smoke in the garden as Tobacco Mosaic Virus can be transmitted from a smoker's unwashed hands while handling plants.
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.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage. Sanitation is important so be sure to remove all debris at the end of the season.
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.
Whitefly: These are small white flying insects that often rise up in a cloud when plants are disturbed or brushed against. Burpee Recommends: They are difficult to control without chemicals. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for pesticide recommendations.
Why did my lisianthus plants arrive with the flowers cut off? Lisianthus benefits from pinching to encourage bushiness and we pinch our plants before shipping. If there are any flowers, we also cut them off before shipping to reduce the stress on the plant. They will definitely bloom once they are established in your garden!
Can I grow lisianthus from seed? Lisianthus can be grown from seed but it is very challenging and takes a long time from sowing until flowering. We only offer lisianthus as plants at this time.
Can I grow lisianthus in containers? Yes, the shorter varieties are fine for containers.
Does lisianthus attract pollinators? Yes, lisianthus attracts bees and butterflies to the garden.
Is lisianthus an annual or perennial? It is a tender perennial that is usually grown as an annual.