Answer: Bacterial wilt, a problem for growers in Northeastern and North Central states, is spread by spotted and striped cucumber beetles. Keeping the beetles away, therefore, is the key to protecting your plants from wilt. Start by ordering resistant varieties of cucumbers, then plant a ring of radishes or some marigolds around each cucumber hill as a beetle deterrent. Heavy mulching is highly recommended, and, if yours growing season permits, plant late, after beetles lay their eggs. You might also dust seedlings with rotenone early in the season before beetles reproduce. Finally, if the disease does hit, destroy affected plants, and, if practical, cover, the remaining plants with cheesecloth.