Give poinsettias a final pruning by the end of the month before the fall flower begins – Orlando Sentinel

A question. Hibiscus has many flower buds that drop before opening. She hasn’t done this before. Why the sudden loss of flowers?

Answer. Several residents have reported hibiscus bug infestations causing green shoots to gradually turn yellow and fall off. The eggs of this fly-like insect are laid on the shoots and hatch into the form of yellow caterpillars that resemble caterpillars. You can open a yellowish bud to find the larvae, but they are very small. Removing infected shoots and those on the ground can help control this pest. Perhaps the best control method is to use a systemic insecticide available from local garden centers applied as a spray or to treat the soil according to the instructions on the label. These products introduce hibiscus to control the plant that affects midges.

s. Our angel’s horn froze again but now it’s growing and producing a few flowers. It starts to turn yellow and drops the lower leaves. Could this be a fertilizer deficiency?

a. Seems to me it’s a lack of fertilizer but angel’s trumpet plants suffer from some leaf diseases as well. If leaves are shedding and flaking uniformly, applying compost where allowed can help. If you notice dark spots on the leaves before they turn yellow and fall off, the disease is likely to be affecting the plant and an ornamental fungicide may help, following the label instructions.

s. My Carrie Mango for the first year produces fruit with dark spots. What should I do to control this damage to the fruit in the future?

a. Dark spots on mango fruit often indicate a common disease of anthracnose that has affected trees. The disease begins early during flowering and remains with the trees during fruiting. Once the fruits are infected, it is too late to gain control. Copper fungicides are sprayed during flowering and continued every few weeks until early summer following the directions on the label. Fortunately, the Curry variety has some resistance to disease, so you may be able to avoid spraying. The skins of the mango may be affected and the fruits are edible as long as the fleshy parts you are eating do not rot.

s. When do you give the poinsettia a final pruning before flowering? We have grown about four feet tall.

a. It’s hard to believe, but the time of flowering of the poinsettia is not so far away. For the best growth for your plants before flower start time in early October, give them a final pruning by the end of August. Usually, four to six inches are removed from each main shoot at this time to increase branching and produce many colored balls by Christmas. Also, make sure the plants are kept moist and fertilized with a slow-release product where permitted.

s. We started growing tomatoes for the garden from seed. How do we know when they are ready to settle in the garden?

a. Tomato seedlings grow rapidly during the summer months to produce a transplant in about four weeks. Keep young plants moist and provide full sun exposure. Fertilize weekly with a liquid fertilizer solution mixed at the prescribed rate. Tomato plants are ready for the garden when they are six to eight inches tall and support several sets of true leaves. Usually we try to put them in the garden between mid-August and early September. They do well at this time and begin to set fruit when temperatures are mild in early October.

s. The undersides of the leaves on our plumeria plants are covered with a yellowish powdery substance and turn brown. What can I do to protect the new?

a. Plumeria and cannas both have problems with those yellow, powdery substances known as rust spores that form during the summer rainy season. The rust fungus seems to like high temperatures and humid weather. It is probably best to anticipate this disease each year and apply a fungicide when rainy weather returns or at the first sign of yellow dots on the leaves. Some good rust controls available at local garden centers include the systemic fungicides in the BioAdvanced, Bonide, Fertilome, Southern Ag, and Spectracide lines. Follow the label directions for the selected rust control product to prevent this disease.

s. You’ve heard about keeping spring tomatoes for the fall season. How is it?

a. Extending the tomato season from spring through fall seems reasonable, but the plants don’t always cooperate. Check continued growth in summer for signs of insects and disease. If there are any pests, it is best to start planting new plants in the fall. Otherwise, continue with normal care and your tomato pot plants can begin to set new fruit by early October.

When your existing tomato plants have healthy new growth but the old parts are browning, you can make 6- to 8-inch cuttings to root easily in potting soil containers. Stay hydrated and in filtered sun for a week or two and then switch to full sun. It can be placed in the garden as a transplant in three to four weeks.

s. Many hydrangea plants grow in the landscape in containers and have finished flowering. When should they be pruned?

a. Anytime between now and early September would be the best time to prune hydrangea plants. Remove old flower heads and no more than half of each main stem as needed to reshape the plants. Pruning in mid-to-late summer allows hydrangeas to grow new growth and form buds during fall and winter for the following flowering season.

Tom MacCubbin is Honorary Urban Horticultural Expert with the University of Florida Cooperative Extension Service. Write it down: Orlando Sentinel, PO Box 2833, Orlando FL 32802. Email: [email protected]. Blog with Tom at

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