How to Care for Lilies. During active growth, water freely—especially if rainfall is less than 1 inch per week. Keep lilies mulched so that their roots are cool. The mulch should feel moist, but not wet. Read more about mulching. Apply a high-potassium liquid fertilizer every 2 weeks from planting until 6 weeks after flowering.

Caring for Your Lilies 1. Fertilize your lilies. When they first push up shoots, add a little well-balanced fertilizer. Lilies are fairly... 2. Water your lilies only as needed. Lilies generally don't need a lot of water, so only water if required. 3. Protect from freezing. During winter months, ...