Q: Our hibiscus did not bloom this year after doing so for the last four years. It winters in our home and was fed blood meal once in winter and again in early spring. Chuck Mathis, Powder Springs
A: Tropical hibiscus needs lots of vigorously growing leaves in order to flower well. It is likely the nutrients from blood meal have washed out of the soil by now. The rule for fertilizing tropical hibiscus is “lightly but often.” Try giving your hibiscus a half-strength application of water soluble fertilizer every two weeks.
Q: I had a dogwood planted in my front yard in mid-April. The leaves are curling and the leaves on one branch have turned brown. I have an irrigation system and have also been watering more on recent hot days. Kathy Brumbelow, Cobb County
A: Planting a tree in April, rather than in October, the preferred month, makes it more difficult for the tree to establish itself. The new leaves and rapidly warming temperatures in spring put moisture demands on the roots that are hard to satisfy. Water must be applied directly to the rootball of the tree, typically every day or every other day in the absence of heavy rain. An irrigation system can’t do this.
Personally, I planted a dogwood in March of this year. I examine it daily to be sure the leaves are not drooping. When they do, I pour five gallons of water at the base of the trunk. I’ll do this until the leaves drop in November and will keep a sharp eye on it next summer.
Q: I’ve been trying to find fertilizer for my centipede lawn. Your web site recommends 16-4-8. Could I use a 32-0-10 fertilizer at half strength? Theron Kendall, email
A: Centipede grass is sensitive to high soil phosphorus levels. That’s why 15-0-15 or 16-4-8 are typically recommended. But you’ve found an answer to the grade school question: “Why do I need to learn math?”! Half-strength 32-0-10 equals an application of 16-0-5, which should be fine for centipede grass. Do it twice each year. Don’t forget that a soil test (www.georgiasoiltest.com) can give lots more information on what your lawn needs.
Q: I want you to develop a really cold tolerant St. Augustine grass. We had a cold winter and only half of my ‘Palmetto’ St. Augustine grass survived. Morgan Williams, Winston Salem
A: My own St Augustinegrass lawn was started from sprigs that were harvested from a 20-year-old lawn near downtown Atlanta. I figured that if the grass had survived that long, it was cold hardy enough for my lawn in north Decatur. I have never had any cold damage. Developing a brand new St Augustinegrass variety is tough because modern varieties do not produce viable seed. You have to collect pollen from wild plants and individually fertilize grass plants growing in a greenhouse. It’s not a job I want to attempt!