14. Questions & Answers

Is it safe to mulch with grass clippings that have been treated with herbicides?

It would be best to find out from your neighbors whether they are using herbicides before using their grass clippings. If you see dandelions in the grass, that is a good sign. However, the most commonly-used herbicide, "2, 4D," is not absorbed by grasses in amounts great enough to affect vegetables. Don't use suspect clippings in the green state. Either compost them or put them aside for a couple of weeks. Soil microbes usually break down the chemical weed killer in a week or two. If you know when the spraying has occurred, and several rains and a couple of mowings have occurred since the spraying, the residue should be gone. Of course, grass clippings that have had no spray are the best.

Since sprouting in soil produces sprouts of higher nutritional value than sprouting with water only, what is the best kind of soil to use?

Seeds can be sprouted in soil, indoors or out. The sprouts will indeed be of higher nutritional value than the sprouts that are produced with the use of water only, especially if the soil is properly prepared. The soil should consist of one part fine compost, one part fine topsoil, and one part sand.

Is it best to wash the salt off of seaweed?

Organic Gardening magazine, March 1980, page 20, says that it really isn't necessary to wash the salt off of seaweed, as the amount of salt that might cling to the seaweed is minimal. Dig the fresh seaweed into the soil to avoid leaching out of nutrients that will occur if you allow it to heap up and decay. Organic Gardening says that seaweed is nutritionally similar to barnyard manure, except that it contains twice as much potassium. It is also high in iron and zinc, and contains some iodine.

What is "Diatomaceous Earth?"

It is composed of the fossilized shells of microscopic one-celled algae. It is a natural product, and kills insects mechanically. The shells break down into tiny, razor-sharp needles of silica, and the silica particles attack the wax coating that covers the insect. The insect gradually loses fluid and dies in about twelve hours. Diatamaceous earth is fine, dry dust, and is best applied when plants are wet, or it may be dissolved in water. In a five-gallon sprayer, place a teaspoon of liquid soap compound in a quart of warm water. Add one-fourth pound of diatomaceous earth, and top off with water. Keep solution agitated as you use it. Diatomaceous earth works against insects only when they are in their pupal, maggot, or grub stage. This substance can irritate your lungs, so wear a protective mask when using it. Don't use formulations which are mixed with pyrethrum and chemicals. If you can't find it locally, it can be ordered from Golden Harvest Organics.

What causes carrots to be bitter?

An insufficient or uneven supply of moisture or of nutrients will produce bitter carrots. Insects or disease can also cause bitterness. If you follow the instructions in this lesson, as to composting, mulching and watering, your carrots should be healthy and sweet.

Is it advisable to grow vegetables or trees over or near a septic tank?

Root vegetables and leafy crops can become contaminated if grown near a septic tank. The roots of trees can damage the drainage pipes. Shallow-rooted plants would be less of a problem, but there would still be some risk of infection from any food plants planted over or near a septic tank. It would be best to plant somewhere else.

Is soil-testing a foolproof method to determine the actual needs of the soil, or is one better off just feeding the soil with organic matter and thus building its fertility?

I grew many successful vegetable gardens without any soil testing. An article in the August 1982, Organic Gardening magazine ("Organic Discoveries," Jeff Cox, pp. 104-105) offers documentation of the fact that frequently these tests are relatively meaningless. Dr. William Liebhardt, Assistant Research Director at the Rodale Research Center, says that a reliable nitrogen soil test is just not available. Dr. Liebhardt sent the same soil to 69 major laboratories, and received analyses and fertilization recommendations that varied wildly. Measurements of organic matter varied almost as much as the nitrogen recommendations. The 69 laboratories' measurements of phosphorus, potassium and soil pH also fluctuated widely. Cox's opinion is the same as mine. Feed the soil, and let the soil feed the plants. He spoke with Dr. Roger Pennock, soil scientist at Penn State University, about the carbon-to-nitrogen ratio. Dr. Pennock said, "The end product of organic matter decay—soil humus— tends toward a perfect carbon-nitrogen ratio of ten to one. At this level, and up to about fifteen to one, nitrogen will be released to the plants as they need it." Finished compost has the 10 to one ratio, and is the perfect balanced fertilizer.