A cucumber plant wilts from lack of water, but after a good watering, it perks back up. Cucumber plants that continue wilting and begin dying even after watering are likely suffering from bacterial wilt. In this case, the wilting process cannot be stopped, but there are ways to prevent it.
Bacterial wilt is the major cause of cucumber plants that wilt and die. It is an infection that spreads through the entire plant, plugging up leaves and stems with a gooey, sticky substance that prevents water and nutrients from travelling through the plant. The easiest way to tell if a cucumber plant has bacterial wilt is to cut off a stem and place a finger on the cut end. If a sticky substance comes out of the cut end and sticks to your finger, the plant is suffering from the disease.
Cucumber beetles are responsible for spreading bacterial wilt. When they feed on an infected plant, the bacteria stays in their body, even through an entire winter. When the infected beetles feed on a healthy plant with a deep cut or wound, the bacteria pass into the plant, infecting it. Since cucumber beetles feed on cucumber plants already suffering from wilt, most carry the bacteria and spread it from plant to plant.
Eliminating cucumber beetles is the best way to prevent bacterial wilt. Clear out all remaining vegetation in the fall so that the beetles have no place hide during the winter. Tilling the soil in the spring kills any eggs. Covering emerging cucumber plants with cheesecloth or floating row covers keeps the beetles out. Insecticides containing pyrethrum kills adults, reducing the population and the risk of spreading the bacteria.
There is no treatment for cucumber vines infected with bacterial wilt. Dig up and discard the affected vines. This helps prevent the spread of the disease among remaining cucumber vines and other garden plants, such as pumpkin, cantaloupe and squash. Infected vines allowed to remain in place also attract other pests that damage other garden plants.