EDITOR’S NOTE: A University of Florida faculty member and Nassau County Extension Horticultural Agent, Rebecca Jordi addresses some of the questions she receives about landscaping and gardening in northeast Florida. The Extension also offers helpful clinics throughout the year, providing assistance to local gardeners on Amelia Island and in the surrounding areas of Nassau County, Florida.
_____GARDEN TALK Q & A____
QUESTION: I continue to have sprouts coming up from the bottom of my crepe myrtle. When should I prune them? EF
JORDI: These sprouts growing around the base of the crepe myrtle are called suckers. If you leave them they will eventually become large making the tree have more trunks than desired.
We would suggest limiting the crepe myrtle to no more than five main trunks with three to five being acceptable. This makes the tree much easier to manage. It is appropriate to prune suckers from any tree any time of year. Removing them early, while the stem is small, is the preferred practice.
Remember anytime a pruning cut is made there is the potential opportunity for decay to occur. Therefore, removing the stem when it is small minimizes the possibility for disease. No need to paint the cut with any substance. Allow the natural ability of the tree to seal over the pruned area. Several pruning sessions may be required to control suckers from forming but eventually fewer and fewer will be produced. You may also remove any dead or decaying branches any time of year. Stems rubbing each other, those growing straight up from a branch (water sprouts) or those growing toward the trunk should also be pruned.
QUESTION: My gardenia plant has yellowing leaves. It is planted next to the house near the down spout. Do you think it is getting too much water? What fertilizer should I use? HB
JORDI: I believe you have diagnosed the problem yourself correctly. The gardenia is indeed experiencing some stress. The dark green veins with yellowing between the vein tissues indicate a nutrient deficiency. It is difficult to determine exactly what nutrient might be lacking without a tissue sample but we can try a few things to determine what might be the cause. Gardenias, like azaleas, camellias, and evergreen plants generally prefer well-drained, acid soils. The heavy amount of water this plant has been receiving has contributed to the stress.
In addition, there is a possibility the soil pH is too high as gardenias prefer the pH between the ranges of 5.0 – 6.5. Often soils in our area are higher than this range which means the plant is unable to absorb the required nutrients from the soil efficiently. When the plant is unable to take up the nutrients through the root structures, the leaves will eventually start to yellow. If you just add iron sulfate or magnesium sulfate the plant leaves may respond, but it will probably only be a temporary fix.
My suggestion would be to relocate the plant to an area where it will not be exposed to heavy amounts of water. In addition, use a pine mulch product which will help alter the soil texture and lower the pH temporarily. Keep the mulch light (only a few inches deep) and be sure it is not touching the trunk of the shrub. This is true for any tree or shrub. When fertilizing use a fertilizer specifically formulated for “acid loving” plants. Be sure to follow the directions on the label.
QUESTION: I planted tomatoes and beans a few weeks ago and they are not doing well. What is wrong? MJ
JORDI: July in Florida is a little late or too early (depending on how you look at it), for the plants to produce fruit. It is too hot for tomatoes or beans to produce efficiently. Insects and disease are at their peak performance and vegetable plants are normally on the decline. Tomatoes and beans should have been planted between February and April in the spring or plant a fall crop in August. The link below is a publication on growing vegetables in Florida from the University of Florida/IFAS. This publication contains a chart on when to plant vegetables here in Northeast Florida, how to prepare the ground, when to water, how to fertilize and much more information. Feel free to contract me if you need more information. http://edis.ifas.ufl.edu/vh021
Rebecca L. Jordi
UF/IFAS Environmental Horticulture
Nassau County Extension
543350 U.S. Highway #1
Callahan, FL 32011
904-548-1116 or 904-879-1019