Dig up the garden soil with a spade or gardening fork until it is free of large clumps. Add 3 inches of peat moss and blend it into the soil to a depth of 6 inches.
Space the leopard lilies 4 inches apart in the garden, planted 4 inches deep. Water to a depth of 6 inches after planting.
Fertilize the leopard lilies once a month while they are growing. Use a 5-10-10 fertilizer at half the recommended rate. Throw it on the soil around the lilies and water to a depth of 6 inches to soak the fertilizer to the root zone. Use the hose to wash off any fertilizer that lands on the plants.
Control weeds around the leopard lily to avoid competition for soil moisture and nutrients. Weeds also harbor pests and fungal pathogens.
Keep the soil moist at all times of the year.