How to control aphids on your hibiscus plants
Question: Our hibiscus plants have aphids in the tips of the shoots. How do we control them without affecting the bees?
Answer: Curling leaves and stunted shoots are often signs aphids are sucking juices from hibiscus leaves and stems. One natural way to dislodge these pests is with a strong stream of water sprayed onto the pests feeding among the hibiscus shoots. The control can be temporary, so a follow-up treatment may be needed.
Insecticidal soaps can also give good aphid control. These act as contact insecticides and only effect the insects treated. They can be directed on the aphids, following label instructions, so as not to affect other beneficial insects, such as bees. Where needed, they can also be washed off the plants once aphids are under control.
Q: Sod webworms are ravaging our St. Augustine lawn. What is an effective control?
A:
Garden centers have what you need to control the feasting sod webworms. Most lawn insecticides give control of the larva stage, chewing on the leaf blades. Garden Centers also likely have a natural control of the spinosad insecticide labeled for use with home lawns. Do not expect to control the adult stage, which is a moth with lawn sprays. These are not damaging your lawn and should gradually decline when the larvae are eliminated by insecticide treatment.
Q: Peas were planted in a raised bed with other vegetables. They grew and declined without producing. Why?
A: Traditional garden peas and not southern peas, need cool weather to be good performers. The seeds may germinate and start to grow during the hotter months but shortly decline. Try a different time of the year to be the most successful. Plant garden peas November through February. Be ready to provide protection during freezing weather. Southern peas are a spring through summer crop and flourish during the hot weather.
Q: We are looking forward to growing our own petunias for fall. Should we use pelletized seeds?
A:
Hard to see and sow seeds are often marketed in a pelletized form. The coating around the seed moistens and allows the seed to sprout and grow into the surrounding soil. Planting instructions commonly note not to cover the seeds with soil after sowing. Small seeds in any form are best sown in a germination mix. The small soil-like particles prevent burying the seeds. Petunia seeds are small but can usually be sown as they come from the pods, but a pelletized form may make it easier, especially for first-time gardeners.
Q: Our garden hose sits out in the sun and the water can be very hot when it is first turned on. Will this affect the plants?
A:
If the water is too hot for you to handle, it is too hot for the plants. It is probably best to allow the water to run from the hose onto the ground until it is a reasonable temperature. Normally this is a very short period of time when water comes from a municipal water supply or well.
Q: We are from the North and would like to grow foxgloves. If I obtain plants from a hometown garden center, will they grow and flower here?
A: Traditional foxgloves are biennials and need a winter of cold weather to develop their flower buds. Normally, seeds are sown in the spring and grow during the summer to flower the following spring after passing through the winter. Selections obtained from a northern nursery or garden center likely still need the winter cold, which may not be adequate in Florida. A few new varieties do not need as much cold and flower in the spring after a fall sowing. One variety is Camelot, available as seed to sow in late October or November from mail-order suppliers.
Q: We would like to plant a new tree in the front yard that stays less than 25 feet tall, provides good shade and does not have a root system that runs over the surface of the ground or destroys the sidewalk and driveway. Any suggestions?
A:
Small trees normally have a limited root system, but that does not mean they won’t have some surface roots, especially as you approach their trunks. Also, noticeable surface roots are often determined by the soil moisture levels and soil compaction. Smaller trees providing good shade are the taller crape myrtles, plus redbuds and tree ligustrums. If you can tolerate heights a little above 25 feet, select from the yaupon holly, river birch, sand live oak and winged elm. It is best to keep all these trees 20 feet or more from sidewalks and drives to avoid damage from surface roots. These trees are also windresistant, surviving well during past hurricanes.
Tom MacCubbin is an urban horticulturist emeritus with the University of Florida Cooperative Extension Service. Write him: Orlando Sentinel, P.O. Box 2833, Orlando FL 32802. Email: TomMac1996@aol.com. Blog with Tom at OrlandoSentinel.com/tomdigs.