Pests in the Potato Patch

Pests in the Potato Patch are often the six legged variety and maybe the worst ones are the Colorado potato beetle (Leptinotarsa decemlineata). CPB in my log book. These nasty beetles feast on potatoes, tomatoes, eggplants, peppers, and petunias. CPBs in adult and larvale stage eat the leaves and stems of the plants, not the roots. This reduces their ability to photosynthesize and results in reduced potato yields.

CPB adults are yellowish orange with black spots behind their heads and 10 black stripes on their wing covers. (You get that magnifying glass and look close and count them!) They spend the winter as pupae in the soil and emerge in late spring and walk to host plants. Then they lay clusters of yellow, oval-shaped eggs. The larvae hatch and feed for up to 3 weeks before they pupate in the soil. These prolific critters can have three generations per year in the South.

The easiest and best way to prevent damage to your potato crop is to make a barrier between the pest and the plants with a lightweight floating row cover. Place the row cover over the potatoes after planting and leave it on until you are ready to harvest. If you don't use a row cover, regularly inspect your plants and spread a heavy layer of straw mulch around your potato plants. The mulch holds in moisture and prevents weeds(you knew that) but it also makes it harder for the CPBs to FIND your potatoes! The mulch also serves as a micro-habitat that suits natural predators, like ground beetles, which feed on larvae, and lady beetles and lacewings, which feed on eggs and larvae.

Organic farmers and gardeners are familiar with companion planings, so plant coriander, sweet alyssum, fennel, dill, and cosmos around your potato patch and attrack beneficial insects. Plant potato varieties that mature before reach their height in early summer, such as 'Caribe', 'Superior', and 'Yukon Gold'.

Another way to prevent insect pest problems is to use a plastic-lined, V-shaped trench can to reduce the number of adults that can get into the potato patch. (Remember, they are WALKING.) As head for the plants, they fall into the trench and can't get out. Be ruthless and kill them all.

This takes diligence every morning too. But if you are an organic farmer, you already know that every day in every way something must be done to manage your crops without harmful pesticides. It is work. But it is good work. And the potatoes are your reward.