Eremurus, commonly known as foxtail lilies, should be planted in the fall so the tuberous root structures can become established during the winter months and grow their fleshy roots. Eremurus bloom in the spring and early summer and have long tail-like flowers in various colors such as crème, orange and pink. Plant eremurus tubers in full sun. They are hardy to USDA hardiness zone 5.
Prepare the soil by amending it with a couple inches of organic matter such as sand, peat moss, cow manure or compost. Till the top 12 to 18 inches with a garden rake, hoe or tiller and then mix it all together to make a rich, well draining planting bed.
Use a trowel to dig holes that are three times as tall as the Eremurus tubers. Typically, holes that are about 6 to 8 inches deep will suffice.
Set one tuber in each hole with the bud facing up toward the sky. Space multiple Eremurus tubers about 12 to 15 inches apart.
Backfill the soil and pack it down with the palms of your hands. The soil needs to be firm so there are no air pockets, which can later rot the tubers.
Water the planting site well and mulch, if desired, with 2 to 3 inches of mulch (e.g., pine needles, bark), which will help retain water.