Question. Very few flowers are opening on our hibiscus plant as the buds turn yellow and drop. What should we do?
Answer. Try a systemic insecticide made for trees and shrubs following label instructions. Some are applied to the soil and others are sprayed onto the plants. This year many residents are reporting the premature bud drop due to the hibiscus midge, a fly-like insect that lays eggs on the buds. These produce larvae to enter and cause yellowing. Often you can open the buds and find the small yellowish stage. It also helps to gather up the fallen buds, but that could be a lot of extra work.
Q. My neighbor is growing vegetables hydroponically and cannot find types to plant during the summer. Are there any vegetables for this time of the year?
THE. Frankly, summer is not the best time for vegetables using any cultural technique. Most summer selections are not that easy to grow under hydroponic conditions, but one you might like to try is the cherry tomato. Some dwarf varieties are available that might set fruit during the summer. A few herbs to try include mint, oregano and sweet marjoram.
Great vegetable gardening is just beginning in August with the fall warm season crops. All tomatoes should start to do well along with peppers, squash and cucumbers. The most popular hydroponic crops of greens, especially lettuce, grow best starting in October.
Q. Several new bougainvilleas started from one of our plants are about two feet tall and growing in containers. Should they be topped to make them bush out?
THE. One tall shoot is not going to make an attractive bougainvillea plant. It is a good idea to remove the growing tips which should cause branching to produce more attractive shrubs. Now look best with several main shoots to form the bush or to send up a trellis. Periodic removal of the terminal shoots may be needed to form growths with many flowering stems by late fall. Hurry to complete all pruning by the end of August.
Q. My pineapples used to be large but have been only small ones in recent years. How do I help the plant produce big ones again?
THE. Pineapple production in the same soil with the same plants eventually declines. Every three to four years, give your plants a fresh start from tops or offshoots saved from your crop or purchased fruit. If growing in containers, use those of five gallons or more filled with fresh potting mix. When planted in the ground, improve sandy soil and old garden sites with lots of organic matter and manure. Then keep the new plants moist and fertilize lightly but monthly March through October or use a slow release product at the vegetable or fruit rate on the label.
Q. Lubber grasshoppers are chewing the leaves on our crinum lilies. We eliminate them when noticed. Is there any way to control these pests before they cause damage?
THE. Some residents say lubber grasshoppers get large enough to pull a wagon around the yard, but they are surely exaggerating. These grasshoppers do grow large by common insect sizes, being three inches long and just about unstoppable with pesticides. By now you either have to pick them off your plants and dump them in rubbing alcohol or do the grasshopper stomp.
Insecticides never seem to be a good answer for lubber grasshoppers that are quite big from the start. Now extension agents recommend hand picking these leaf-chewing insects from plants when noticed in the spring and destroying them. They are often found in clusters when young and easy to control. If an insecticide is needed, select one of the synthetic pyrethroids available under several brands at garden centers and follow label instructions. Often you have to spray the grasshoppers directly to obtain good control.
Q. My lawn has large weedy areas. Can I replace these areas with new sod during hot weather and intermittent rains?
THE. Summer is not a bad time to restart a lawn in full sun locations. You do need to give the site good soil preparation of at least a light tilling and acidity adjustment if needed. Do remove all the weeds. Since you will not be able to fertilize the lawn until October, make sure the grower is supplying good green grass that indicates it has been well fertilized. After installation, you have to provide the water if the daily rains fail to keep the soil moist. It is not abnormal to water once a day the first week, every other day the second week and every third day during week three. If the weather is hot and dry, additional waterings may be needed. Also, make sure to apply a turf fungicide shortly after sodding.
Q. I normally prune my azaleas after they bloom in spring but had to delay the trimming this year. Do I still have time to cut the plants back to the desired size?
THE. Azalea pruning time is over if you want attractive blooms for late winter or spring. The plants are in the process of forming their flower buds and major pruning would affect the blooms. Now, the plants won’t mind if you give them a pruning and should produce lots of growths to renew the shrubs. You may get a few blooms from within the plants on the remaining older stems, but the normal spring display is usually lost until the following year.
Tom MacCubbin is an urban horticulturist emeritus with the University of Florida Cooperative Extension Service. Write him: Orlando Sentinel, PO Box 2833, Orlando FL 32802. Email: TomMac1996@aol.com. Blog with Tom at OrlandoSentinel.com/tomdigs.