Examine potato plants regularly to detect pest outbreaks before they become major problems. Many pests can be controlled without using chemicals, especially if detected early. In most cases, disease control will not be necessary in the home garden. The most critical period for weed competition is during early growth, from emergence until plants are approximately 12 inches tall. Control common annual weeds such as redroot pigweed, lambsquarters, and nightshade by hoeing or pulling during the hilling operation.
Cultivation can actually spread troublesome weeds, such as thistle and quackgrass.
Once plants reach their full size, cultivation must be shallow to avoid pruning potato roots near the soil surface. The adult beetles, which overwintered in the soil, emerge in the spring to lay eggs on susceptible host plants. Adult beetles have round, hard, yellow wings with ten black stripes. Larval feeding defoliates the plants. Larvae are brick-red with two rows of black spots on each side.