Q: This year, some of my caladiums have been slow to sprout new shoots with colorful leaves. Should I give them special treatment?
A: Regular care is all that is needed for caladiums to regain their vigor after a cold winter and dry spring. Freezing temperatures may have affected some bulbs (actually tubers) that are close to the soil surface. We often say it slows down growth, but in this case it slows down spring growth. Growth may also be slowed if caladiums are located in areas that do not have sufficient water supply until the rainy season returns. The good news is that the plants are vibrant and growing. Give these sprouts a colorful foliage watering to keep the soil moist. Also, if allowed, apply a slow-release fertilizer to increase the growth and vigor of your caladium. Even better news is that these plants’ late start means they may survive long into late summer, or have a period of rest before they traditionally decline. Prevent damage next winter by maintaining a light mulch on the soil surface.
Q: I have a small podocarpus shrub that has multiple buds coming out of its base. One turned brown. Will the entire plant decline? What should I do?
A: I hope this is a case where one shoot was damaged during planting or care and the damage caused it to decline. Prune the shoots leading to the plant with areas of healthy tissue. This may come down to earth. Podocarpus is susceptible to a disease known as mushroom root rot and should be replaced if large parts of the plant begin to decline. Before repotting, remove the soil from the affected area and replace it with fresh soil. There are no fungicides to control or prevent this disease.
Q: I am planting rows of small dwarf yaupon hollies. Should I shape it into a ball, or should I grow it with the shoots touching each other like a thick hedge?
A: One of my friends called the round shape a “meatball.” Dwarf yaupon holly is hardy and will grow to about 4 feet wide and tall if left unpruned. Many gardeners prefer round shapes. Some residents transform them into other geometric shapes or animals. Other gardeners prefer the hedge look and keep their plants about 18 inches tall and wide. Be aware that pruning that keeps plants dense can promote diseases that cause partial decline. This dieback can be prevented by growing yaupon holly in an area with good airflow and watering only during dry periods of the year. If necessary, cut off dead areas and apply a fungicide to control disease.
Are you a Central Florida gardener? Here’s your to-do list for June
Q: Our garden is starting to decline. What should I do to prepare the area for the next planting?
A: Pay attention to your declining spring garden and remove old plants and weeds. Insects and diseases can continue throughout the summer on remaining plants. This is the perfect time to cover the soil with clear plastic and expose it to the sun for 6 to 8 weeks to burn off nematodes and other pests. Before solarizing, till the soil and add organic matter, such as compost, if necessary. If you don’t solarize your soil, you can always add organic matter before your next planting. Weeds often harbor pests, so keep them under control. Also check the acidity of the soil and adjust the pH if necessary. The next planting time for warm-season crops is mid-August.
Q: I have a century plant that is 25 feet tall and is about to bloom. Will the plant die after flowering?
A: Contrary to what the name suggests, century plants grow amazing stems and bloom within 10 years of being planted. Another unique feature of this plant is its gradual decline after flowering. However, there is usually no need to worry too much as there will be many new shoots growing at the base to restart the life cycle. This plant may excite neighbors, but the flowers are yellow-green and not very showy, making them difficult to tell apart at the top.
Q: It’s time to add new mulch to my landscape plantings. Should I remove the old one and add the new one, or just topdress it?
A: Leave the old mulch in place because it contains the roots of landscape plants. Removing mulch can cause the plant to decline by removing some of the important roots that absorb water and nutrients. You’ll also probably have some of the mulch layer left over, so only a light top-dressing will be needed to bring it back to the 2-3 inch level recommended for most trees and shrubs. Remember to keep mulch several inches away from the trunks and stems of all plants, new or old.
Q: I am growing cannas in containers, but some of the new shoots are dying. I cut off the old flower heads. What happens next?
A: You should notice more buds sprouting from the rhizome. Rhizomes can be thought of as stems that are near or in the soil. These will produce new flowers. Old flower stalks can continue to grow for a while if the flowering part is removed. Eventually these can also be pruned back to rhizomes. Cannas need to be transplanted as the rhizomes fill the container with new growth. If your container is fairly small, you may need to transplant it this summer. You can remove the rhizomes and break apart the clusters to form containers for new plants or add them to sunny flower beds. Keep seedlings moist and feed with a slow-release fertilizer if possible.
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.
