Question: We are trying to spend money on gardening. How far apart can I plant autumn petunias in flower beds? How many petunias should I put in a hanging basket?
Answer: Most petunias can spread out over time and don’t mind some gaps between plants for a while. The general rule is to space petunia plants 6 to 12 inches apart. With water and monthly fertilizer, they can grow together and bloom fairly quickly. A frugal gardener plants a single petunia in a 10-inch diameter hanging basket, but must wait about a month for the flowers to fill up and begin covering the sides. Planting three petunias in a hanging basket will fill the basket faster. This can give you a container full of flowers almost instantly. Keep all seedlings moist and feed with a slow-release fertilizer according to label directions.
Q. My ponytail plant is about 20 feet tall. I would like to prune it. What should I do?
A. Gardeners usually prune ponytail plants slightly. Sometimes a ponytail is called a “palm”, but this is incorrect. The main bud is located at the top of the new shoot that emerges from the swollen trunk. If removed, the plant must grow new buds to continue growing. If necessary, cut off side shoots and long leaves. If you decide to cut it back by cutting off the top part of the stem, the plant will slowly put out new shoots, albeit normally. This often occurs when ponytail plants are damaged by cold weather.
Q. I have a peach tree that started blooming a few weeks ago, but it seems like it’s early. What do you want me to do?
A. There are autumn flowers on the branches of peach trees, but there is no need to worry. This often happens if the tree loses its leaves a little early or if the variety has very low cold resistance. There are usually a lot of flower buds in the branches, too many in fact. Once consistently cool weather returns, flowering should slow until late January or February when more flowering and fruiting are needed. So, please enjoy the autumn colors of peach blossoms for a while.
Botanist: To bloom or not to bloom, that’s the question of coleus.
Q. Help! Hibiscus is turning yellow. Are there any treatments to apply?
A. Several residents have expressed concern about yellowing hibiscus leaves. Most can be attributed to dry soil conditions. Rainfall has fluctuated in many regions this year. Dig down and check soil moisture. If it’s dry, the problem is solved and you need more water. Too much moisture can cause root rot problems. The photos in your email seemed to suggest that one or two stems were more affected than others. Check the stems for disease. If necessary, prune them from the hibiscus to prevent further infestation.
Q. There is white stuff on the leaves of my African violets. What is this and what treatment do you recommend?
A. Most residents with African violet collections end up getting the white cottony puffs known as mealybugs. They are difficult to control and can form large populations. The traditional method to prevent minor infestations is to dip a cotton swab in a rubbing alcohol solution and touch each mealybug. This solution can be made by mixing alcohol and equal amounts of water. If the infestation is severe, insecticide treatment may be necessary. You can also use insecticidal soap, but this can damage the leaves. Try treating a few leaves and letting them sit for a day or two to see if there is any damage to the plant. Treat mealybug infestations if damage is minimal. If the plant is heavily infected, it is best to discard it and replace it.
Q. When I cut off the branches of my crape myrtles near the ground, small buds appear again. Is there a coating to prevent growth?
Central Florida gardens in November
A. Other than using pruning shears, there is no magic cure for these sprouts. Young crape myrtles are especially known for their ability to regenerate new shoots from the base. As the shrub or tree begins to age, the number of new shoots will decrease. Wounds caused by string trimmers and mowers appear to encourage new growth. Therefore, it is best to keep mulch near these plantings to minimize regrowth.
Q. The curly-leaved croton that I grow in a container loses its leaves rapidly, even though I water it when the soil dries out. What should I do?
A. Do a little detective work to dig into the soil and make sure the root ball is completely moist. Water may flow to the outside of the root ball without moistening the soil. If the soil is dry, place the container in a saucer to keep it moist and turn it towards the root ball. Also, try watering a little earlier if the soil starts to dry out. Next, check for mites and scale insects. These pests are small and may hide among the leaves and stems. It sucks the sap from the croton, which can cause the leaves to fall off. If any of these pests are present, try a horticultural oil spray according to label directions to treat both the leaves and stems of your plants.
Q. My grapefruit tree is bearing fruit this year, but the shape of the tree is distorted. When is the best time to do the necessary pruning?
A. There may not be a good time to prune a citrus tree, but if necessary, it is usually pruned in late winter before flowering and growth begins. This way the tree won’t waste a lot of growth or start producing fruit that may be pruned later. Keep in mind that the more you prune your tree, the less it may produce next year. Prune as needed to even out the tree’s shape and keep future fruit within easy reach.
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.
