Organic Integrated Pest Management involves tackling pest problems one step at a time with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops.
- Cultivate a good environment for your crops: healthy soil, sufficient space, nutrients and water, suitable temperature, soil pH. Practice crop rotation to reduce the chances of pests and diseases carrying over from one crop to the next. Clear old crops promptly, so they don’t act as a breeding ground for the pest. Choose suitable varieties that resist the pests you most expect.
- Cover or protect the plants physically from the pests (mulches to stop soil-dwelling pests moving up into your crops, netting, rowcover, planting diverse crops, and even trap crops)
- Provide habitat for natural enemies and other beneficial insects
- Monitor crops regularly at least once a week and identify any pests you see.
- Introduce natural enemies of the pest (bacteria, fungi, insect predators or parasites)
- Hand pick (or trap) and kill the pests if the pest population is above the action threshold. Many fruit and root crop plants can take 30% defoliation before any loss of yield. Where the crop is the foliage, this may be too much!
- Use biological controls (often derived from natural enemies) if the damage is still economically significant after trying the earlier steps in the process.
I recommend the ATTRA online publication Organic Integrated Pest Management.
Each of the 22 pages is a poster, complete with good photos and concise clear info.
One of our biggest garden pests is the deer, which are especially fond of sweet potatoes. We use motion-sensor water sprayers initially or in years when the deer pressure is low. For worse years we install an electric fence with a solar-powered charger. Last year our electric fence didn’t keep the deer out, so this year we have a double layered fence to make sure.
At the other end of the size scale are aphids. We plant sweet alyssum in our beds of broccoli and cabbage to attract insects that will eat aphids. We sow about 200 plugs for 1500 row feet (450 m) of brassicas planted as two rows in a bed, and pop one alyssum plug in the bed centers every 4ft of bed or about one alyssum per 4 plants. We transplant these the same day that we replace any casualty broccoli and cabbage plants.
We transplant some bush nasturtiums in with our first plantings of cucumber and summer squash. They are said to repel some cucurbit pests such as squash bugs., but I can’t vouch for that. Radishes in cucumber or squash rows are said to repel cucumber beetles and squash bugs. I haven’t tried that. There are a lot of companion planting ideas out there, but most have no scientific evidence for effectiveness.
In late May or early June, we transplant some flowers in our garden to attract pollinators and pest predators. We use circles cut from plastic buckets to surround these clusters of flowers so that inexperienced helpers don’t pull them out as weeds. We use a combination of sunflowers, dill, borage, cosmos, calendula, tithonia (Mexican sunflowers), zinnias.
We also sow sunflowers in our bean beds at each succession. These attract birds and pollinators, while also acting as landmarks for our harvest progress.
In our hoophouse we have been tackling nematodes for several years. This year we have planted the nematode areas in French marigolds and sesame (apparently particularly good in deterring root knot nematodes, the type we have.) Some other nematode areas have been planted with Iron and Clay cowpeas. Unfortunately we now have an aphid infestation on the cowpeas! We are trying blasting the aphids off the plants with a strong stream of water from a hose. Later in the summer we will solarize some of the nematode areas.