How to Grow a Tiger Lily in Southern California

Test the soil pH in a well-draining area that receives partial shade to full sunlight at least six months before planting. Tiger lilies prefer slightly acidic soil of around 6.0 to 6.5 pH, so add 3/4 to 1 1/2 pounds of elemental sulfur per 50 square feet to lower the pH by one full point, or add 3 1/2 to 4 pounds of garden limestone per 50 square feet to raise it one full point, if necessary.

Amend the soil with 2 to 4 inches of composted steer manure or compost in early fall about two to three months before the first frost of the season, using a spade fork for the task. If you have heavy clay soil, add 4 inches of compost and 1 inch of coarse river sand; work it in 12 inches deep.

Plant tiger lily bulbs about three times as deep as the bulbs are tall, usually between 6 and 12 inches, a few days after amending the soil. Space the bulbs 8 to 12 inches apart. Plant containerized tiger lilies as deep as they were planted in the containers at any time after the threat of frost passes in spring until the end of the growing season. Look on the stem to see the mark left by the soil line to help determine how deep to plant containerized specimens. Plant tiger lilies 2 to 3 inches higher than usual if planting in heavy clay soil.

Water the lilies after planting and once a week during active growth to a depth of 6 inches. Don’t water from above to avoid wetting the foliage after they emerge, but simply place the hose near the plants' bases and allow the water to soak into the soil. Check how deep you watered by inserting a skewer in the ground about 2 inches from the lilies, pulling it out and seeing how far the water reaches.

Insert 2-foot-tall garden stakes 6 inches deep in the ground about 1 inch from where you planted the bulbs. Tie the lilies to the stakes when they reach about 1 foot tall, using twine. Change out the stakes for longer ones after every 6 inches of growth. Tiger lilies vary in height between 3 and 6 feet tall, so select stakes about 1 foot taller than the height of the flower stalks as they grow.

Mulch the soil around the lilies with 1 to 2 inches of straw mulch or shredded bark after the stalks emerge. Keep a distance of 1 to 2 inches from the stalks. Add an additional 1 or 2 inches of mulch just before the first frost of the season, and change the mulch out for fresh mulch after the threat of frost passes in spring.

Cut the stalks back to up to one-third of their total length after flowering when they turn yellow, using sterilized pruning shears for the job.

Check the tiger lily leaves regularly for aphids. Aphids measure about 1/16 inch long, have small white, green red, black or brown bodies, and usually feed on the bottoms of leaves -- but you might find them elsewhere. They leave honeydew on the leaves that leads to sooty mold fungus. Mix together 2 1/2 tablespoons of insecticidal soap with 2 percent potassium salts of fatty acids in a handheld spray bottle. Spray the aphids until covered, repeating once a week as needed, to treat.