Q: My clivia, which I am growing in a pot, has been severely damaged by freezing. The pot is packed tightly and all but two bulbs have died. How can I replant what survives?
A: Clivia, also known as kaffir lily, is a real delight with its colorful orange and yellow flowers that bloom from spring to early summer. As you may have experienced, plants are damaged by freezing and become very tender. Now is the time to separate dead plants from surviving plants. Climbia is a member of the amaryllis family, but does not produce large bulbs. Instead, clivia has thick, fibrous roots attached to a swollen base known as a rhizome. Save damaged but growing plants by removing the dead parts. Repot each into a smaller container, or add the two surviving plants to one slightly larger container. Plants prefer potbound. Use good quality organic potting soil and grow your new plants in a sunny to shaded area. Keep it moist and feed with a slow-release fertilizer.
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Q: Almost all of my shrubs are recovering from the cold. Many of them withered and returned to the soil, but are now sprouting new buds. How can I get new plants to grow again? Is it time to fertilize?
A: The best way to speed up the recovery of cold-damaged plants is to water and fertilize them. Fertilizer restrictions begin in June in many counties, so now is the time to make your last payroll before summer. In restricted areas, planting in the ground cannot be fertilized from June to September. There are usually no restrictions on edible or container plants. Apply a slow-release fertilizer that can nourish landscape plants for several months by the end of May, and again in early October. For container plantings, use similar products according to label directions.
Q: A lot of weeds have started to grow in bare areas of my lawn. Can I use weed control to get rid of weeds and encourage new growth from nearby grass?
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A: Areas affected by winter damage, disease, and insect infestation are filled with weeds. Now is a good time to control these weed zones. If there are large bare areas, using grass to fill in the gaps is the best way to restore your lawn. Once weed control products are no longer effective, large areas will become overrun with weeds again. Some weed control products can inhibit the growth of good runners. If the area where weeds are growing is relatively small, using a herbicide tailored to your lawn type may provide good control. Make sure the product is made to control the most growing weeds. Next, if weeds are infrequent, use a spot weed spray to only affect the areas of concern. If you have a lot of weed spots, you can apply a weed and feed mix product according to label directions. Note that in most areas, the last application of fertilizers through fall, such as weeding and feeding, is at the end of May.
Q: Large yellow spots appear on the leaves of the cucumbers I plant at home, and the leaves gradually wither. What is the cause and how to cure it?
A: These symptoms suggest that downy mildew, a fungal disease, is affecting your plants. This fungus affects pumpkins, pumpkins, and melons. Some cucumber varieties are resistant to this disease, so it should be your first line of defense. Check your seed catalog or seed packet for resistance to downy mildew. Once the seedlings have grown, keep the leaves as dry as possible. Water in the morning so the leaves are dry by noon. Also, use mulch to prevent fungal spores from spreading between plants. Natural insecticides that are effective in controlling downy mildew include need oil and copper-based fungicides. Daconil, a traditional fungicide, also provides some control. Either of these should be applied at the first sign of illness or when illness is anticipated according to label directions.
Q: I enjoy daylilies, but I’ve noticed that many of the leaves have brown and orange spots. What is this? Do I need control?
A: It’s a common disease called daylily rust that ruins the beautiful green color of your plants’ leaves. It is a very prevalent fungus among plants. Affected plants become weak and unsightly, but usually do not suffer significant decline. No matter what you do, your plants will likely develop rust, but you can control it. Controlling daylily rust begins by removing as many affected leaves as possible. Also remove any old leaves that have fallen to the ground. Next, apply a fungicide listed to inhibit rust, such as BioAdvanced Disaster Control, Daconil, Fertilome Systemic Fungicide II, or Spectracide Immunox. Follow label directions and apply spray as needed. Also, try to keep daylily leaves dry, especially during the evening. Some daylily varieties are partially resistant to this disease, but control may still be necessary.
Q: My ligustrum hedge has grown to about 6 feet tall and is missing its base leaves. How far should I cut the plant back to bury it close to the ground?
A: Only heavy pruning can push out the stems and leaf buds from the lower part of the hedge. As a general rule, prune your plants to 1 foot above where you want new growth to begin. In this case, that means pruning the hedge to a height of about 3 feet above the ground. A healthy spruce should regenerate quickly with sufficient water and application of slow-release landscape fertilizer, as permitted. For future pruning, try to keep the base of the hedge wider than the top. This will ensure that all areas of the hedge receive as much sunlight as possible and preserve the lower foliage of the plantings.
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.
