By MARY COLLISTER
© St. Petersburg Times, published May 12, 2000
Ipulled up my petunias, as I discussed in my last column, but decided against adding any more annuals at this time. With the drought continuing, it didn't seem like a good idea. Hopefully the rains will start, and I'll plant more flowers at that time.
The only plant materials enjoying this drought are the numerous varieties of weeds. The lack of water hasn't slowed them down at all. I spent an hour trimming the yellowed branches from the pygmy date palm and pulling weeds in the front yard last Sunday. There isn't too much more to do.
This would typically be a time for fertilizing, but with the drought I wouldn't bother. If you treat for crickets or chinch bugs, read the label of the pesticide carefully. Some chemicals need to be watered in. You may want to time your pesticide application to coincide with your watering day.
A Tampa reader wonders if his lone avocado tree needs another tree to cross-pollinate. The avocado's flowers are bisexual, so one tree should produce fruit. An exception is "Collison," which is widely grown in Florida. This variety is pollen-sterile and must have another pollen source. Bees and perhaps other flying insects act as pollinators.
This reader also has a grapefruit tree that isn't fruiting and wondered about the care. This is a popular landscape tree in the area, so I'll run through the care:
DRAINAGE: The soil must drain quickly. No citrus likes its roots sitting in water. Before planting, you may want to incorporate peat moss, sawdust or ground bark.
WATERING: Grapefruit requires moist soil but never free-standing water. It needs air in the soil. Established trees should be watered every other week. If newly planted, water at least twice a week. Don't let the trees get to the wilting point.
MULCHING: Grapefruit tree roots grow near the surface of the soil as well as deeper, so mulch is beneficial. Use a 2- to 3-inch-deep mulch, but keep it away from the trunk.
FERTILIZING: Use 11/2 to 2 pounds of actual nitrogen for mature trees each year. To get pounds of actual nitrogen, multiply percentage of total nitrogen, as stated on the label, times the weight of fertilizer. It's best to apply a third each in late winter, in June and in August. Spread fertilizer beneath and well beyond the branch spread of the tree, and water in deeply. Use a high-nitrogen formula.
The tree may suffer from iron chlorosis or zinc deficiency. Chlorosis (yellowing of leaves with dark green veins) may also be caused by excess water. Treat with chelated iron or iron sulfate. Zinc deficiency shows up as a yellowish blotch or mottle between leaf veins. Control with zinc foliar sprays. Commercial products are available as sprays containing both iron chelates and zinc.
PESTS AND DISEASES: Aphids, mites, scale insects and mealybugs may be a problem. If these pests' natural enemies fail to handle the infestations, and if jets of water fail to keep the pests in check, spray with appropriate chemicals. If scale remains troublesome, spray with light oil in early spring. Bait or spray for snails and slugs whenever necessary, especially during warm-night spells of winter and spring.
With an appropriate maintenance routine, you should have more grapefruit than you can eat.
Hope your yard is making it through the drought. Keep hoping for rain.