QUESTION: I've read that too much tilling with a mechanical tiller can ruin soil. I put a layer of leaves in my garden, and I want to work them into the soil. J.M., Weatherford
ANSWER: Rotary or power tillers are OK to use, and they are good tools when the garden is being created. They are excellent for blending compost and other amendments into the soil before planting is done. The point that organic gardeners are trying to make by discouraging mechanical tilling is that after gardens are planted, gardeners should stand outside the bed at all times to avoid compacting soil near the plants and their roots. Additional tilling does more harm than good because it destroys layers of microbes and organic matter in the soil.
QUESTION: I live on 2 acres with many native oaks, three of which died during the past year. The dead trees were growing close together, and their leaves turned brown and began to fall. The entire tree seemed to die at once. I have two more oaks with similar symptoms near the dead trees. What is the problem, and what can I do? B.S., Kennedale
ANSWER: If the trees are post oaks or blackjack oaks, the culprits probably are summer heat and dry soil. If they are red oaks or live oaks, the problem could be oak wilt disease. My recommendations for treating oak wilt are on the Dirt Doctor website. Look in the Library section under entries for oak wilt and for the Sick Tree Treatment. The treatment involves aerating a tree's root zone and applying soil amendments.
QUESTION: When should I replant a chinquapin oak that was planted about three years ago? I planted it at the correct depth, but I did not remove all of the girdling roots. The tree is struggling, so I need to dig it up to correct the root problem. S.P., Wichita Falls
ANSWER: Replant after daytime temperatures are consistently below 90 F. Temperatures in the 80s are ideal to encourage fall root growth. Keep the roots hydrated, and treat them with a mycorrhizal fungi product such as Thrive by Alpha BioSystems and the tree should do well.
QUESTION: What is an effective organic method for getting rid of kudzu growing in a bed of Asian jasmine? B.P., Plano
ANSWER: Using goats or other grazing animals to physically remove kudzu is the best solution for your situation. Grazing animals eat kudzu like candy, and kudzu is cultivated in Japan to feed livestock. One business in the Dallas-Fort Worth area that rents goats for weed control is Cathy's Critters in Collin County (972-562-0583; www.cathys-critters.com/additional_services.asp).
QUESTION: Our Spanish oak is buzzing with bees. Why are bees attracted to the tree? Should we be concerned? S.B., Fort Worth
ANSWER: There could be a beehive in the tree, or stress could be causing sweet fluids to ooze from the tree and attract bees. Bees are harmless when they are foraging, so don't be alarmed.
QUESTION: What do you recommend to control leafhoppers in an organic vineyard? Can I safely use vinegar as a herbicide near the trunks of the grapevines? R.S., Corsicana
ANSWER: Spraying vinegar herbicides around the woody stems is an excellent way to control weeds near grapevines. Spraying every two weeks with Garrett Juice, Bio-Wash and orange oil should take care of the insects you listed. Add 1 tablespoon of Bio-Wash and 1 ounce of orange oil to each gallon of Garrett Juice. (Soil Mender Plant Wash may be substituted for Bio-Wash.)