Q: My four bougainvillea shrubs are dropping their leaves badly. Fertilize and water regularly, but not excessively. I sprayed neem this morning, but I didn’t see any insects. Please help me.
A: The cold weather in February was not good for bougainvillea. Some people fell to the ground, while others sustained various injuries to their limbs. According to the photos in your inquiry, you can see that the small twigs with leaves are damaged and have turned brown. This can be the cause of leaf loss as the twigs completely decline. You can either let nature take its course and allow the branches to decline naturally, or you can prune to remove as much dead or decaying material as possible before new buds fill in the gaps. Using a fungicide labeled for ornamental plants may help prevent further fungal activity. In either case, the plant should recover and take on its memorable, colorful appearance, but this will most likely be in the fall or winter.
Q: I have a 20-year-old desert rose that I thought was dead, but it has started sprouting from one side of the root ball. Old growth is mushy all the way to the root ball. I’m hesitant to remove the mushy old growth and don’t know what to do. Could you please give me some guidance?
A: Remove the mush. Rake or trim until you find solid plant tissue. Rot is bad for desert roses and can lead to fungal growth and continued decline. After cleaning, spray with a fungicide spray to reduce mold activity. Avoid getting water into the wound to allow it to dry and heal. Keep the soil moist and fertilize with a slow-release fertilizer.
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Q: My red maple tree has several small, dead branches. Should I remove them?
A: Red maple is a good tree for wet home landscapes. After all, there’s a reason they call these swamp maples that way. In drier landscapes, the tree seems to struggle a bit and become more susceptible to fungi that affect its branches. If you find a weakened or dead limb, it’s best to remove it immediately. The affected area is removed and replaced with a healthy joint or trunk. It may be best to have a certified arborist look at your tree and recommend any necessary care. An arborist can also remove the necessary limbs if they are out of reach.
Q: I have a number of Norfolk Island pines that appear to be dying. How long should residents wait for recovery?
A: Many gardeners have asked the exact same question about the decline of Norfolk Island pines. These are not true pines, but tropical-like pines that are much less cold hardy. They are sensitive to cold and are clearly damaged by freezing weather. However, there may still be some hope for recovery. If you look closely, you’ll notice that many of the shoots on the branches and trunk are green. Although the overall extent of the reduction has not yet been determined, it is certain that the loss of many limbs and stingers occurs. Most of Norfolk Island’s pines may recover, but they will not have the attractive tree shape they once enjoyed. The trunk is likely to be barren and grows primarily from the top. Give affected trees a little more time to start producing new buds, then decide whether to keep them as landscape features.
June is almost here. Here’s a Central Florida gardener’s to-do list:
Q: My pineapple plant used to produce well, but now I can only harvest small fruits. How can I get the big one again?
A: Pineapples that have been in production for more than three years will generally have smaller fruit sizes as the plant’s clusters naturally expand. You may want to continue fertilizing monthly from March to October to see if that helps grow larger fruit. Usually the best way to renew the vigor of your plantings is to remove some of the new plants and start a fresh pineapple patch.
Q: I have a 3-foot-tall avocado tree that I need to move to another location. Can I move now or is there a better time?
A: The success rate of moving woody plants is very low during the hot summer months. Although this tree is small, it looks like it could be dug up with almost bare roots. This means that it has lost most of its small and important roots. It’s probably best to let this tree grow until late fall or winter, then move it to a less stressful time. Even then, it may be best to transplant the small tree into a container to give it some shade and plenty of attention before planting it in the landscape.
Q: We have several amaryllis bulbs planted at home and they usually produce lots of flowers. This year, the leaves were green, but there were few flowers. Did the cold affect them?
A: There may have been cold damage to the flower buds, but most of the amaryllis we see locally are flowering normally. Perhaps there is a cultural problem, such as the plants being too crowded after years of growth or the bulbs sinking too deep into the soil. Plants, like humans, need a break from time to time, so you may need to hold back on flowering. Plants must store a certain amount of energy to support good development of flower buds. Keep the beds moist from spring to fall and apply a slow-release fertilizer in March, May, and early October to support next year’s good growth and flower bud development.
Q: I am planning to solarize my planting bed to control nematodes. Do you work with organic matter before or after treatment?
A: Heating the planting site to burn off pests is called soil solarization and is best performed when the flower bed is ready for planting. Add all necessary organic matter to improve the soil before treatment. The area is then thoroughly moistened and covered with clear plastic for 6 to 8 weeks during the summer. Hopefully this will raise the soil temperature to near 140 degrees Fahrenheit. Once the solarization process is complete, the seedbed is ready for planting with minimal disturbance.
Tom McCubbin is an emeritus urban horticulturist for the University of Florida Cooperative Extension Service. Write to Orlando Sentinel, PO Box 2833, Orlando, FL. 32802. Email: TomMac1996@aol.com.
