Common Disease or Cultural Problems
Alternaria Leaf Spot: Small, round reddish brown spots with white to gray 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.
Bud Drop: When the buds fall off the plant generally due to lack of food or water. Burpee Recommends: Regular watering and fertilizing.
Plants die over the winter in recommended zones: Wet soils with poor drainage in winter can kill plants. Burpee Recommends: Make sure plants are in a well-drained soil. For container grown plants, add one zone colder than your zone when selecting varieties, and keep containers in a protected area outside, mulch heavily.
Root Rots: A number of pathogens cause root rots of seedlings as well as mature roots. Burpee Recommends: Pull up and discard infected plants. Make sure your soil has excellent drainage. Contact your Cooperative Extension Service for recommendations.
Yellow Leaves: When the leaves turn yellow and drop off the plant. Burpee Recommends: Do not be alarmed, this happens to the older leaves several times a year. When the old leaves drop, the new ones will begin to grow.
Viral Diseases: Viral diseases spread by insects may cause deformed or cupped foliage with mottled patterns. The plants lose vigor. Burpee Recommends: There is no cure. Remove and destroy infected plants. Control aphids and other insects which spread the disease. Be careful when working in the garden and do not touch any plant until you have washed your hands or gloves after touching infected plants. Clean tools after working with each plant.
Common Pest 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 who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Japanese Beetles: Burpee Recommends: Hand pick early in the morning into a bucket of soapy water.
Mealybugs: Mealy bugs are 1/8 to ¼ inch long flat wingless insects that secrete a white powder that forms a waxy shell that protects them. They form cottony looking masses on stems, branches and leaves. They suck the juices from leaves and stems and cause weak growth. They also attract ants with the honeydew they excrete, and the honeydew can grow a black sooty mold on it as well. Burpee Recommends: Wash affected plant parts and try to rub the bugs off. They may also be controlled by predator insects such as lacewings, ladybugs and parasitic wasps. Check with your Cooperative Extension Service for pesticide recommendations.
Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
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.
Does hibiscus make good cut flowers? No, the flowers close up in one day and will not last if cut.
Why are the leaves turning yellow and falling off? During the season, hibiscuses shed its older leaves to push out new growth.
Does hibiscus attract butterflies? Yes.
Is hibiscus deer resistant? Yes.
When will my hibiscus bloom? Hibiscus bloom from July to September.