QUESTION: To what depth should lime, compost and 19-19-19 fertilizer be tilled in for a home vegetable garden? The soil is hard-packed clay. We have been using the same garden area for the past several years. R.B., Greensburg, PA.
ANSWER: Unless you have soil that is deficient in calcium, lime is unnecessary. And 19-19-19 is a high-nitrogen synthetic fertilizer that I don't recommend. Apply compost at least 2 to 3 inches deep, and add the other amendments later as time and money allow. They include greensand, cornmeal, dry molasses and volcanic rock such as lava sand. For best results, till all the amendments and fertilizer to a depth of 8 to 10 inches. The fertilizer should be organic. I am not sure what is available in your area, but feed stores and garden centers should be able to get corn gluten meal, a powerful organic fertilizer with pre-emergent herbicide qualities. Just do not use it where crops are planted from seed until the plants are up and growing. Other good natural fertilizers include cottonseed meal, soybean meal and fish meal.
QUESTION: Would lusterleaf holly or yaupon holly do well near a pool and pavement on the southeast side of a house? C.R., Plano
ANSWER: Yes, unless the soil stays too wet because of activity at the pool.
Will natural herbicides kill grass but not Asian jasmine? J.L., Dallas
ANSWER: If you are talking about vinegar, it is a nonselective herbicide and will damage any green plant it hits. The trunks and stems of woody plants can withstand the spray, but foliage cannot.
We have discovered leaf cutter ants trying to strip our pear trees of their leaves. We know that citrus is good for several things, and we have a Vita-Mix blender in which I put peelings from two oranges and one grapefruit along with about a pint of water. How should I use this mixture? B.H., Eustace
ANSWER: Citrus pulp is a great soil amendment and is good for neutralizing root knot nematode problems in susceptible plants. A tea made by soaking citrus in water, if strong enough, is effective at repelling or killing insects. Texas leaf cutter ants can be killed by flooding their large colonies, after building earthen dikes around them, with water and a plant oil pesticide.
QUESTION: I live in Central Texas, where we have black soil. I need to know the best way to keep the soil easy to work. I have been told that using rice hulls will help. C.H., Rogers
ANSWER: Rice hulls and most other forms of organic matter will help improve soil. Composted organic matter works even better. You also should add the other organic amendments that I discuss on my Web site (see Resources). Healthy soil will be created fairly quickly if a combination of materials is used. My favorites are dry molasses, lava sand, cornmeal, Texas greensand and fish meal.