Can I Save My Cucumber Plant Once It Has Downy Mildew?

Downy Mildew

• Downy mildew, also called powdery mildew, grows from spores of the Erysiphe cichoracearum fungus. Symptoms include yellowing, twisty, powdery and dying leaves, though many leaves and stems take on a fuzzy white appearance before dying. Fungus spores can defoliate entire plants and reduce vegetable and fruit yields.

Treatments

• Treat powdery or downy mildew with fungicide sprays to reduce spreading. The University of California at Davis' UC IPM Online recommends commercial fungicides, horticultural oils, neem oil, jojoba oil, biological fungicides and sulfur sprays. Prune away infected foliage and dispose of it to protect the garden.

Prevention

• Prevent future outbreaks of downy mildew for the best garden success. Start new gardens with fresh new soil to eliminate old mildew spores. Cornell University's Vegetable MD Online notes that most commercial cucumber varieties demonstrate resistance to this disease. Plant these mildew-resistant cultivars at correct spacing and in full sun to encourage warm air circulation. Spray mildew-prone gardens with fungicide regularly throughout the season to prevent outbreaks.

Cucumber Care

• The right planting and care leads to healthy, resilient cucumber plants, which survive disease better than sickly, weak plants. Put cucumbers in full sunshine, and use organic compost and 5-10-10 fertilizer at planting. Stake the plants to keep them off the ground, and expose them to a constant supply of sunshine and fresh air. Give each cucumber at least 2 to 3 feet of space for air, sun and growth. Water cucumbers at their bases with 2 inches of water every week, and don't over-fertilize.