Natural Pest Management: Safeguarding Your Garden without Chemicals
We gardeners are willing to spend the majority of the year planting, watering, weeding and harvesting because we want food that is better than we get at the grocery store. We want more flavor and nutrition, and far fewer chemicals. However, we don’t intend the lack of chemicals to be an open-invitation to all the little critters to come eat our precious plants and produce! Let’s talk about how to avoid poisons in our garden while still being able to harvest beautiful and nutritious fruits and vegetables.
For starters, we want to begin with disease-free seeds. We’ll store our own saved seeds in a cool, dark and dry place. When buying seeds, we’ll buy from reputable dealers, usually within the USA. When there are diseases one year, we’ll buy disease-resistant varieties the next year. To do this, I’ve learned to look for the capital letter, “F,” to buy tomato seeds resistant to fusarium or a “V” to choose a variety resistant to verticillium wilt. If you do buy seedlings instead of seeds, be sure to examine them for disease before purchasing.
Begin with good nutrition:
Once in the soil, plants need good nutrition to avoid disease just as we humans need good nutrition to stay healthy. Plants get their nutrition from the soil, so we try to keep the soil undisturbed as much as possible. After all, nature has a perfect design for soil so that it is able to nurture plants. It does takes time to create good topsoil, so when gardening in a new plot, you might want to side-dress your plants with compost or fish emulsion. Compost can be the perfect nutrition, but if you don’t have enough, buying fish emulsion is a good option. Fish emulsion is a by-product of processing fish, and it contains NPK as well as micronutrients like calcium, magnesium, sodium, sulfur and chlorine. The downside? Fish emulsion indeed smells “fishy,” so you probably don’t want to add that to indoor plants. I tend to also forgo fish emulsion for any outdoor potted plants because raccoons are far too fond of its smell.
I use compost tea a lot early in the growing season. It's such an excellent nutrient suppliment and seems to make a huge difference in preventing diseases, including fungal infections of plants.
Barrier methods:
Even when crops have excellent soil for nutrition, critters can still manage some damage. Barrier methods are an additional way to help discourage both large and small critters. For example, squash vine borers can totally destroy seedlings, but they’re not difficult to outsmart. We’ve learned to wrap each young cucumber or squash stem with a strip of aluminum foil that extends a bit into the soil to protect the young plants’ lower stems. The foil tends to expand on its own and we don’t gather it until cleaning up the garden in the autumn. “Companion planting” marigolds between the early vines will act as an additional deterrent.
Protect from soil fungi:
A different concept of barrier works for fungal infections on our tomato plants. These infections usually come from spores in the soil which get on the plants after rain splashes soil onto their stem and leaves. A “splash barrier” will prevent this source of fungal disease. The barrier can consist of dried organic material like leaves or newspaper laid on the soil around the plants. It is important to keep these materials from touching the stem because straw or leaves will heat up when composting and injure the tomato stems.
Floating row covers:
Other barrier methods consist of putting row covers over vines, either with hoops or “floating” row covers. These will have to be removed temporarily when tending the plants, and then removed completely when the plants begin to bloom and need pollination. The majority of insects can be avoided in this way. Additionally, if you construct raised beds, a barrier of half-inch hardware cloth can be placed under the soil to prevent rodents from tunneling under and feasting on the precious sweet potatoes.
Electric fences:
The “ultimate” barrier method for large animals is an electric fence. At our place, this has seemed necessary to keep the deer at bay from the corn patch. When we have gathered enough corn for eating and preserving, we then remove the fence. The deer and raccoons are then welcomed to the remaining ears and stalks for their winter meals.
Traps:
Besides barrier methods, “traps” are also used for cucumber beetles as well as Japanese beetles. We only tried the
Japanese beetle traps a couple of years, but were quite sure the scent was inviting more beetles into our garden than were trapped! We did learn to place the traps about 30 feet downwind from our plants, but we just weren’t impressed with any significant drop in the number of beetles. I would also take early morning walks around the fruit trees and grapes with a soapy bucket of water and knock beetles into the water. What finally seemed to do the trick was “Milky Spore.” It’s a one-time job to bury this powder in shallow holes around the most affected plants. Milky spore is actually a bacteria that continues to multiply in the soil for years. It kills the Japanese beetle grubs that mature in the soil from eggs. Because these eggs are deposited under affected plants, it only needs to be buried under the plants most affected. Although Milky Spore is relatively expensive, it seems to result in far fewer Japanese beetles within a couple of years.
New Paragraph
Milky spore:
Milky spore is a bacterium that kills the grubs of Japanese beetles.
Usually the beetles will go to specific plants such as fruit trees, grapes, and okra. It is applied by digging shallow holes underneath the affected plants and putting a tablespoon or two in each hole. The bacteria of milky spore will continue to destroy the grubs for many years, as long as there are grubs to feast on.
Some people think that it also is helpful with the larvae of the Mexican bean beetle. I hope that's true because these beetles have been very destructive to the late season bush and pole beans this year. Besides rotating these crops, milky spore will hopefully slow down and gradually eradicate these beetles.
Diatomaceous Earth:
Diatomaceous Earth, (DE), is another non-poisonous way of killing insects. DE is harvested from the sea from tiny organisms called “diatoms” that have died and accumulated. Diatoms are composed mainly of silica which actually has many health benefits for humans. But not to digress, silica is useful in the garden because it has sharp edges which scratch the insects’ exterior skeletons and causes them to “desiccate.” They then die over about three days. Be sure to buy “food grade” DE which is readily available at garden stores or even online in bulk. The downside of using DE is that it’s a fine, white powder that easily washed away with water and then needs to be reapplied. I keep a Parmesan cheese container filled with DE in the hoop house where slugs are especially fond of the cooler weather brassica plants.
Getting creative:
Sometimes we can concoct solutions using various methods of insect control. For example, our hoop house seems to be the perfect home for slugs who really love munching-to-death seedlings like lettuce and the brassicas. When fruits are maturing, snails then enjoy eating those like the ripening tomatoes.
Vine borers are another pest that is really tough on both the spring and summer seedlings. Even though the zucchinis don't seem quite so precious when August comes around, we are cheering for them in the springtime and hate when they get destroyed by vine borers.
Slugs and vine borers take different methods of control, but I begin with cutting yogurt containers into rings that get snuggled in the soil around each newly planted seedling. Then after each watering in the hoop house, I again sprinkle diatomaceous earth, the white powder, around the plants. This combination has made a powerful difference in helping our plants successfully reach maturity and having produce with fewer blemishes.
Clean out diseased plants:
Knowing that different “pests” are found on different plants allows us a couple additional methods to keep their numbers down. First, cleaning up the garden in the autumn doesn’t mean leaving the garden bare. In fact, cover crops provide living roots which sustain the microbes and fungi that will deliver nutrients to our crops the following summer. However, it does mean removing any diseased plants. You may even want to burn plants with evident disease rather than including them in your compost.
Rotate your crops each year:
The second method of reducing disease is to rotate garden crops annually. In the simplest form, “rotation” means not planting anything where it was planted the previous year. I do realize that’s not so simple when rotating around perennials or when we have the permanent hoops or fencing for climbing plants like beans. Sketching out a garden plan each year seems essential, especially if we keep the previous year’s plan for comparison. The biggest help I’ve found comes from Shepherd Ogden’s, “Straight-Ahead Organic” book. It suggests a four year rotation guide which will also allow us to place our plants where they will best benefit from what was planted there the previous year.
The best produce may still have a few flaws!:
After all this effort, I have to admit that some of our fruits and vegetables will still have imperfections. Therefore, the final solution has been to change my attitude! I realize we’ve been taught to expect flawless fruits and vegetables from the grocery store, but this perfection is most often accomplished with the use of pesticides. We can wash the outside of the grocery store’s apple or strawberry, but that doesn’t get rid of all the poisons that they’ve incorporated while growing.
In other words, our apples and strawberries may not be flawless, but they’ll be wonderfully nutritious, flavorful and free of chemicals. I especially like the fact that when an insect does damage a plant or its fruit, the plant pulls more nutrients from the soil for its defense. That means that produce with “flaws” is actually more nutritious! With this in mind, I just cut around the little “scab” on the apple skin before eating it and still enjoy a strawberry that the Blue jay has already sampled. I would not want the garden area to be void of other creatures, because a healthy “soil food web” consists of billions of creatures above and below ground. Let’s enjoy being part of nature, knowing that the pest management principles we use will keep the majority of our produce almost flawless, but also delicious and plentiful.
