Question: Our hibiscus looks great and has lots of blooms. Unfortunately the blooms fall off before they actually open. We don't see any pests on them. D.F., Argyle
Answer: Hibiscus are heavy feeders. Add alfalfa meal and use liquid organic fertilizer with every other watering, at least until the flowers are holding.
Question: I read an article about using baby shampoo as a substitute for mechanical aeration, but I forgot the application rate per 1,000 square feet using a hose-end sprayer. Can you give your thoughts on using this method?B.B., Grand Prairie
Answer: That's an old recommendation that is silly at best. What we recommend is covered in detail on my website. Amendments and bed prep are under Guides. All the organic amendments and procedures help the tilth of the soil. For a one-time increase in the fluffy texture of the soil, add 16 ounces of hydrogen peroxide to each gallon of Garrett Juice spray and apply about a gallon per 1,500 square feet. You can find the recipe for making your own batch of Garrett Juice on my website if you do not want to purchase the bottled concentrate.
Question: What could I plant underneath a huge fig tree? I need something that my beagle Barney can run on. Other than Persian ivy, Asian jasmine or dwarf mondo, what do you suggest? I am not opposed to some type of crushed rock or mulch.D.M., Arlington
Answer: The only other choices would be the native horseherb. It and ophiopogon (mondo grass) could be mowed, but they will need to be replanted from time to time if they receive much traffic. Otherwise, decomposed granite should be about 1 inch deep. Lava is the best gravel mulch, used at a 2-inch depth. Native shredded mulch should be 3 inches thick.
Question: What can I do for squash vine borers? I have tried beneficial nematodes, Bt liquid, Neem oil and Bt powder. I have been told to replant, but they only go dormant and come back next year. I have lost a lot of plants.B.T., Dallas
Answer: One thing I would try with the next crop is working natural diatomaceous earth into the beds before planting at the rate of 1 to 15 pounds per 1,000 square feet. The available silica helps the pest resistance of the plants. Several gardeners have reported success using this technique.
Question: My East Texas children insisted on giving me a dogwood tree for Mother's Day. It is about 6 feet tall. They put it in a huge clay pot with good soil and thick mulch. Right away it developed powdery mildew. I'd like to know what you recommend I treat it with and how. R.C., Dallas
Answer: Spray with cornmeal juice made from soaking horticultural cornmeal in water or Garrett Juice with hydrogen peroxide added. Make sure the trunk flare is well-exposed and apply a layer of cornmeal on top of the dirt, covering its surface.