Question: Many bougainvilleas in our neighborhood are in full bloom, but our bougainvilleas are green and just a few flowers dotted around the plant. How can I make more flowers bloom?
Answer: The reason your bougainvillea won’t bloom is probably because you take too much care of it. Plants may seem to enjoy the luxury of plenty of fertilizer and water, but this often results in slow growth or failure to bloom. Some of the most attractive bougainvilleas are found in old residential areas with little or no maintenance. The best way to get your bougainvillea to bloom is through neglect. Start care by fertilizing with a slow-acting landscape product in the spring and perhaps early summer. After that, water only during dry periods. Let the plants grow. If you trim too much, your bougainvillea will have fewer flowers and look younger. Complete the minimum necessary pruning by midsummer. Also, make sure your bougainvillea gets plenty of light. Full sun is best.
Q. There are clumps of white cotton-like material on the stems of my Pitosporum, and some of the leaves are black. What is happening to our shrubs? Is there anything I can do?
A. It appears that a swarm of cottony cushion scales has taken up residence in your pitsporum, as identified in the email photo. These are boring, sucking insects that produce sap and excrement on which sooty mold fungi grow. If left untreated, the cottony cushion scale will kill the stems and eventually the plant. Control with natural horticultural oil sprays. For the spray to be effective, it must coat the insects and sooty mold. Follow label instructions and may need to be reapplied within 3 to 4 weeks. Oil sprays for landscape plants are usually found at independent garden centers and hardware stores. Gardeners also find that applying a systemic insecticide to the soil beneath Pitosporum can help control it. If the infestation is severe, both oil and systemic insecticides may be used.
Q. There are seed pods hanging from my crape myrtles. Now that flower season is over and our trees have lost most of their leaves, should we cut them off? If I leave it alone, will a new one emerge next year?
A. Removing all the tiny seed pods seems like a tedious task to me. Do not prune at this time to encourage new growth. Crape myrtles are in a dormant period that should last until February or March. Stimulating growth can make tree and shrub morphology more susceptible to cold. In late winter, feel free to remove the ends of branches with seed pods on them to give the plant a little more tidied-up appearance. Removing or leaving branches and seed ends will not affect future flowering.
Q. Some of our crown of thorns plants are about 4 1/2 feet tall and need to be cut back to about 2 1/2 feet tall. I usually cut it back by now, but I forgot to cut it back this fall. Are you okay now?
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A. It may be safe to cut back the crowns of bramble plants in the fall, but due to the cool weather and short days, growth is not expected. If your plant doesn’t look too bad, it may be best to enjoy it for a few more months and cut it back in late winter or early spring. This plant is also cold sensitive and will be affected by frost and freezes if not grown in a sheltered area.
Q. I have vegetable and flower seeds in my refrigerator, some of which are 5 years old. Do these have the ability to germinate?
A. Some seeds of each type are more likely to survive if kept cool in a sealed container or plastic bag. It’s amazing how long seeds can be stored. If you have seeds that are normally sown directly into the ground, test a few seeds by placing them between layers of damp paper towels and storing them in a warm place in a plastic bag. After a few days, you can check for germination and decide whether to sow the seeds. Seeds to be sown for transplanting can be started in shallow containers of potting soil or germination mixture. Scatter the seeds and cover loosely with one of these mixtures. If you keep them moist, you may find seedlings ready for transplant within a few days to a week.
Q. The vine growing on the wall has produced pearl-like fruit. What is a vine? Is its fruit edible?
A. Although this vine is suitable for wall covering, it does not produce edible fruit. The vine is a creeping fig, firmly attached to any structure. Like ivy and Asian jasmine, it can accelerate the decline of the cement that holds the wall in place over time. Also, when you try to remove the vines, they stick tightly together and are difficult to loosen. The pear-shaped green fruits that grow on mature plantings are interesting but are not considered edible. The plant’s sap is toxic to some people and can cause skin irritation.
Q. One of my viburnum hedges has grown too tall for the landscape. Can I prune it now or should I wait until spring?
A. Most common hedge plants, such as viburnum, ligustrum, anise, and podocarpus, are cold hardy but can be affected by freezing. Most gardeners will take the opportunity to prune to the desired size even as winter approaches. However, if you want to be on the safe side, enjoy some more green foliage and do any necessary pruning around mid-February.
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.
Central Florida gardens in November
