If you've ever wondered why most farmers and vegetable gardeners don't use mulch (and why we don't put bark and pine straw in a compost pile), here are a few reasons why.
Things You Might Not Think Can Mess Up a Garden
1. Pine-tree bark, cones, and/or straw (or mulch in general): Tree barks can hold larva from beetles and other insects that destroy garden plants. The pinewood beetle (or pine-sawyer beetle) especially can be a problem in places like Colorado (where much mulch is made). Many trees have developed a resistance to symptoms that that beetle causes, so mulch businesses don't always know when a mulch may be infected with beetle larva. In my experience, even a reputable company can wind up selling products that have beetle larva.
Although the pinewood beetle only attacks certain evergreen plants, the pinewood beetle can be a double threat, because it also may deposit microscopic nematodes on tree bark. These nematodes can quickly kill some evergreen plants.
Similarly, other mulches can carry other beetle larva and other kinds of destructive nematodes, including larva and nematodes that are a threat to fruit, vegetable, and some ornamental plant growing. So, avoid mulches and soils with wood or straw that can harbor larva and nemas. Or, to become familiar with which woods and straws are most likely safe, contact your local agricultural extension office, or look up info from ag extensions online.
2. Diseased Leaves and Diseased Fruits: Often, plant leaves (and fruits like pecans) can carry spores of powdery mildew and fungal scab, both of which can destroy a fruit and vegetable garden in late spring and summer. Some ag extensions recommend burning such diseased plant matter, to avoid long-term problems. (And note: Powdery mildew often can't be seen by the bare eye until late spring and summer, so, when you do see that problem, it helps to keep those trees or other plants in mind, so that you can rake up and throw away their leaves as soon as they fall each year.)
3. Diseased Soil: Be careful about moving soils from one place to another. If you know there is a problem like fungal blight or bad nematodes in soil in a certain area, don't move that soil around to other places. Instead, leave the soil in place, and plant lots of nematode-killing marigolds during the spring. Then, cover the problem area with black plastic for several months through the summer, leaving the marigold roots in ground under the plastic. The natural chemicals from the marigold roots, and the lack of rainwater and oxygen under the plastic in summer, should help mitigate the problem. Then, when planting in that area, plant something that's resistant to the nematodes. Asparagus roots repel the nemas that attack tomato roots, for example.
4. Store-bought Potatoes and Store-bought Onions or Garlic: Don't compost nor plant potatoes nor potato skins from the produce section of a grocery store, and don't compost nor plant onions, garlic skins nor garlic cloves from the produce section of a grocery store. Potato blight, and stem and bulb nematodes found in store-bought garlic and onions, are common problems on farms that sell the produce we buy from grocers. So, find seed potatoes and onions in garden shops, and mail-order your garlic. Garden-shop potatoes, onions, and garlic are usually certified disease free.
5. Synthetic Chemical Pesticides: Manmade (or unnatural) pesticides have the potential to kill insects that help a garden thrive. Pollinators include bees and wasps, both or which can die from the wrong kinds of pesticides. Earthworms also can die out from pesticide use. (In fact, earthworms sometimes don't even tolerate heavy amounts of natural citrus peels in a compost!) Not only are synthetic pesticides (and toxic amounts of natural chemicals) bad for garden growing; they're bad for anyone who eats garden vegetables and herbs.
So, what's good in a garden? What actually serves as garden helpers?
That's a long list! But just a few garden helpers include
- eggshells (washed with plain dish soap, rinsed, air dried, and ground in a blender);
- pumpkin seeds (air dried, and ground in a blender);
- banana peels (chopped);
- peanut hulls (and other safe recommendations for aerating soil and composting);
- chicken poop (sun dried/completely cured: found in some store-bought garden soils) Don't use poop from a person nor a dog nor a cat for gardening, no matter how dry or old the poop is!;
- fish emulsion;
- safe amounts of plain sulfur (Read information from agricultural extensions, for more about how to safely use sulfur.);
- hay from a farm or straw from wheat, in order to mulch, if you feel you just have to mulch!
- ladybugs, and
- rove beetles!
