The art of land doctoring is being practiced with vigor, but the science of land health is yet to be born.
—ALDO LEOPOLD, A Sand County Almanac (1949)
Both of my previous books include a chapter in which I explain my nonconfrontational philosophy about insect pests and plant diseases. I feel obliged to write yet again about this topic because I believe the subject is crucial to understanding the potential of successful human interaction with the natural world through a biologically based agriculture. The organic grower who does not understand the importance of cause correction rather than symptom treatment in preventing insect and disease problems is missing out on the pest philosophy of the future.
This book focuses much more on greenhouse growing than my previous books do, and you may be wondering whether that affects how I apply my philosophy. Once we add the artificial confines of a greenhouse, aren’t we just asking for trouble? I do not believe so. What I do believe is that a successful partnership with the natural world requires a complete overhauling of our attitude toward pests. Let me lay it out for you.
Bug picking is not the answer. It is just a temporary solution. The same goes for garlic spray, red pepper, herbal concoctions, necromancy, or whatever. Nor, obviously, are DDT, Malathion, Parathion, Tepp, Rotenone, Sevin, Lindane, Pyrethrum, or any of the thousands of unpronounceable horrors in the lexicon of the agricultural chemist. Basically, none of these techniques, whether chemical or “organic,” is any different from the others. They are all palliatives. The word palliative, derived from the Latin pallium, a cloak, is defined as an action that lessens the pain or masks the symptoms of a problem without curing it. To use a palliative is to cloak or hide the problem.
Insects and disease are not the problem. They are, rather, the symptoms. Their presence is a visible exterior indication that all is not well with the plants. No one would be so simple as to think that scraping off the spots—the visible exterior symptoms— could cure a child’s chicken pox. Similarly, removing pests from a plant does not cure the problem or eliminate the cause. All that it accomplishes is to throw a cloak over the problem.
From a commonsense point of view the organic farmer is to be praised for the decision to avoid toxic chemicals. However, from the point of view of creating a long-term dependable agriculture, the organic farmer who uses natural insecticides is no wiser than his chemical counterpart; different materials but the same mistake.
The First Rule
Once you become determined to eliminate the cause of insects and disease rather than just mask the symptoms, a whole new world opens up. A plant bothered by pest or disease need no longer be seen in the negative. The plant can now be looked upon as your coworker. It is communicating with you. It is saying that conditions are not conducive to its optimum growth and that if the plants are to be healthier next year, the soil must be improved. But to succeed at that you have to accept what I call the first rule of biological agriculture—“Nature makes sense.” If something is not working, it is the farmer’s, not Nature’s, fault. The farmer has made the mistake. You have to have faith in the rational design of the natural world, and thus have an expectation of success, if you hope to understand the potential for succeeding. To do so, it helps to restate Darwin more correctly as “the un-survival of the unfit.”
So how do you learn to grow “fit” plants? By asking yourself a lot of questions:
A field of healthy crops about to be covered by a movable greenhouse.
• Is the soil ready for that crop, or should the rotation or choice of cultural practices be changed? (Some, like the Brassicae, benefit from higher nitrogen availability; others, like tomatoes, will produce all leaves and no fruit when given extra nitrogen.)
• How long ago were the green manure or the crop residues turned under? (Three weeks is the minimum. The soil bacteria need time to digest the green matter and return the soil to its balanced state.)
• Was the compost mature? (Testing kits are available. Immature compost can cause a wide range of problems.)
• What was the preceding crop? (If it was a heavy feeder, are more nutrients necessary?)
• Have you corrected the mineral deficiencies indicated by your soil test? (Trace elements can often be the key. You need a complete soil analysis to get that information.)
• Were the transplants stressed? (If transplanting on a dry, windy day, you need to irrigate immediately. Crops like melons, squash, and cucumbers, for example, which must be transplanted with care, will be far more resistant to cucumber beetles if you give them a few weeks protection by a lightweight spun-bonded cover until they recover from transplant stress.)
• Have you chisel-plowed or subsoiled to break up the hardpan? (Impenetrable or airless conditions under the surface are invisible until you plant a crop and then wonder why it is having problems. Take a shovel and do some digging to find out.)
The idea of learning from your plants that something is amiss and needs correcting is nothing new. Any textbook on mineral deficiency in plants will contain pictures of the symptoms exhibited by plants in response to various mineral deficiencies. A common example that many growers have probably noted is the yellowing of corn leaves when insufficient nitrogen is available. The appearance of insects or disease is just as certain an indication of inadequate growing conditions as are yellowed leaves. The remedy is the same: improve the growing conditions by figuring out what is missing. To accomplish that one must learn what soil conditions favor optimum growth and then attempt to achieve them.
Learn by Observing
Take your lawn as an example. Say you have a lawn that is growing mostly crab grass, sorrel, dandelions, and other weeds but none of the finer grasses that you would prefer. There are two courses of action. For one you could purchase all the heavily advertised nostrums, herbicides, fertilizers, and stimulants to suppress the weed competition so the finer grasses would be able to struggle ahead. Conversely, you could study the optimum growing conditions for the grasses you want and then by adding compost, rock powders, peat moss, manure, aerating, draining, or whatever seemed indicated, you could try to create the soil conditions under which the finer grasses thrive. If you doubt this approach, look closely at wild vegetation on undisturbed land. Certain groups and types of plants grow in one place and not another. The native vegetation is an excellent indication of how differing soil conditions favor the physiological needs of some plants over others.
The same approach suggested for the lawn is valid on the market garden. Whatever crop you want to grow, you need to strive to create the ideal conditions for its needs. Determining the conditions at first may require a little detective work. Closely observe the plants, the insects, the diseases, and every aspect of the garden. Are all the plants equally affected or are those at one end of the row or along one edge not showing symptoms? What is the difference in the soil of those areas? Is that where you limed or didn’t lime because you ran out? Did you compost that area with compost from a different windrow? Did you chisel-plow the whole field or just along that edge? Is the good section where all the fall leaves end up being blown onto? Or where that old pile of rotten hay bales sat for years? If you can find no clues to follow use different soil-building techniques in general next year. Use different types of organic matter or rock powders or trace elements. Make and use more compost. Change your crop rotation. Organize and evaluate all the possibilities and keep experimenting.
‘Indigo’ radicchio.
An Aphidian Example
The one plant pest we have noted in the winter greenhouse is aphids, which appear on our spinach starting in early to mid February. At first, we didn’t mind a few aphids since they washed off easily when we cleaned the spinach. But then aphid predators appeared, and the carcasses of the aphids they had preyed upon stuck to the back of the leaves. When we researched the conditions that cause aphids to flourish, all the literature mentioned nitrogen levels in the soil as the main factor in aphid multiplication. We knew that nitrogen could build up in the soil when there has been no rain or irrigation to flush it. Up till then we had traditionally not watered in the greenhouses from about mid-November to early March since the soil seemed moist enough and evaporation levels were low along with the low sun angle. That seemed simple enough to correct. So the following year we began irrigating thoroughly once a week on sunny mornings starting in mid-January to flush out the excess nitrogen and our aphid problem went away. The extra moisture did not cause any new problems and we continue the practice to the present day.
The Ideal of Organic Farming
Lady Eve Balfour, the British organic pioneer, wrote eloquently about how the early organic farmers solved problems successfully by combining imagination with a belief that answers exist if one looks for them:
Without understanding all that is, or may be, involved, it would appear that by his insistence on the importance of life; of the return of all organic wastes to the soil; of a diversity of crops and livestock; of the right to existence of fauna and flora other than those of direct economic value to himself; by his avoidance of crude chemicals, and his attempt to provide the conditions in which natural biological balance will prevent the multiplication of any one species to pest proportions, the organic cultivator has evolved practices which will one day be recognized as far more scientific than those which at present pass under that name. Many of the so-called improvements in modern agricultural techniques have been well described by Aldo Leopold as improvements to the pump—not to the well. They have been developed as the result of a process of thought which has ignored the complex interplay of species which built the original fertile soils; which has deliberately planned the destruction of whole species without a thought being given as to whether their continued existence may be necessary to maintenance of the soil fertility they helped to build; which has advocated remedial measures, to deal with the problems arising from a declining fertility, which treat symptoms only, and which, ignoring nature’s danger signals, “protect” plants, weakened to the point of having already lost their capacity for “internal self-renewal,” with death-dealing sprays. Thus, to food which is already low in nutritional value (the capacity to transmit energy) is now added the hazard of a host of poisons.
Palliatives are the easy way. But they don’t solve the problem. Whereas momentary reliance on them is understandable, they should never form the basis of your agricultural practices. Removing the symptoms may seem to improve the situation but it is only a cosmetic improvement. Working to establish optimum soil conditions is the most constructive approach in a dependable long-range philosophy of agriculture.