Question. Buds on my gardenia are turning brown and the leaves are becoming more yellow than green. I was told to apply an acid fertilizer. What else should I do?
Answer. Open up one of the browning gardenia buds and you may find at least one of your problems. Most likely, tiny yellow to brown insects called thrips can be seen running about. These are very common in gardenia flowers and hard to control when present in the buds. Next season, gain control early with a spinosad-containing natural insecticide. This insecticide is found in Bonide, Fertilome and Southern Ag product lines usually found at independent garden centers. Ask a garden center employee to locate one for you and follow the label instructions.
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Problem two is likely nutritional. The acid fertilizer might help but get one with slow-release properties to apply once in March, May, August (where permitted) and early October. Also, the yellowing could be due to a magnesium deficiency. Try an Epson salt application using a product labeled for plants at the rate suggested.
Q. I am looking for the most durable bedding plants to last through summer. Which ones are best?
A. My go-to plants for summer flower beds and containers are coleus and pentas. You can’t beat the color that is provided by foliage or flowers. Both are also long-term summer survivors tolerating heat, humidity and rains. They often last through fall and into winter. But, I must be fair to other summer survivors and you could pick from alternanthera, also known as Joseph’s coat, angelonia, begonias, bush daisy, impatiens, melampodium, perennial salvia, torenia and small-flowered zinnias. Out of both lists, begonias, coleus and impatiens grow best in the shady areas of landscapes.
Q. I understand geraniums do not like summer weather but my plants still look healthy and are flowering. What can I do to keep them another year?
A. Consistently hot, humid and wet weather is the downfall of geraniums. The foliage starts to decline and plants rot. Yet, many geraniums are kept for several years with enhanced summer care. Find a spot with good air movement and out of the daily rains. Make sure the plants have some sun and bright conditions. Keep the soil moist but not wet and fertilize monthly to get your saved plants to October when they totally rejuvenate again under normal growing conditions.
Q. My lawn was not fertilized this spring and now I am told I cannot apply fertilizer until fall. What can I do to keep the lawn green?
A. Lawns may yellow a bit but are not likely to die without fertilizer during the summer. Check with your local University of Florida Extension office but most counties appear to allow minor nutrient applications that can often renew the green color of lawns. Also, return grass clippings to the lawn during mowing as these can break down to release some nutrients for growth. Lastly, keep the lawn moist during dry times so the roots remain active and absorb still available nutrients and those formed by storms.
Q. Our young shade tree has limbs that are affecting movement over the yard and sidewalk. Can we do needed trimming at this time?
A. Don’t be in a hurry to remove too many of the lower limbs as research indicates the presence of limbs strengthens trunks of young trees. Instead of removing the limbs completely you might tip them back so they do not affect those on sidewalks. Be careful not to leave stubs that could injure anyone coming to contact with the tree. Gradually the lower limbs can be removed and the canopy raised above sidewalks, lawns and ornamental plantings. Any limb that might be a hazard to those passing by should certainly be removed. Eventually, limbs are normally kept eight-to-ten feet above sidewalks.
Q. I have a great supply of leaf lettuce but it is bitter. When the weather becomes hot or the plants get big, does the taste change?
A. Both the size of the plant and temperature have an effect on the taste and texture of lettuce. This is a cool-season crop that is much milder during the late fall, winter and early spring months. Lettuce also develops the best taste and texture when making rapid growth. It’s a crop to keep moist and fertilize to grow the tender sweeter leaves. By now it is normal to get the tall poor quality plants with the bitter taste. Wait until October to plant your next lettuce.
Q. We have a bird of paradise that has been healthy and growing for ten years but never produced a blossom. Is there an explanation for the lack of flowers?
A. You have been very patient, but now it’s time to have a frank discussion with your plant. Tell it you are going to cut off the free food and put it on a low water diet. Most nonflowering bird of paradise plants quickly get the idea.
It may seem a bit abusive, but reduce watering to only during periods of severe drought. Also, keep feedings to light applications of a low nitrogen blossom booster type fertilizer once in March, May and October. Do make sure the plant has a full sun to lightly shaded location and a 3-to 4-inch layer of mulch over the root system.
Sometimes we are just too good to plants and they take advantage of us. Get tough and you could get blooms within a few months.
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: [email protected]. Blog with Tom at OrlandoSentinel.com/tomdigs.