Eremurus are known for their distinctive, bottle brush flowers that can rise to a height of 7 feet. The blossoms open from the bottom up and are available in colors ranging from white and pink to yellow and orange. These impressive early summer perennials, also known as foxtail lilies or desert candles, tower above other plants and add excitement to any flower garden.
Eremurus are native to the arid grasslands of Afghanistan and Iran. They are relatively cold tolerant if grown in very well-drained soil. Most varieties are winter hardy in zones 6-11.
These clump-forming perennials can have leaves that are grasslike or strappy. The foliage emerges in early spring and the leaves are sensitive to frost. If necessary, protect the foliage with horticultural fabric. In cool climates, plant eremurus in a sheltered location.
After flowering, the leaves will die back and the plant will be dormant until the following year. During summer, fall and winter, it's important for the roots to be in soil that is dry, rather than consistently moist.
Plant eremurus in fertile soil with excellent drainage. When preparing the planting area, add organic matter to lighten the soil and if possible, raise the soil level to improve drainage. A sandy loam is ideal.
Choose a warm location where the plants will get full sun and the tall flowers will be protected from strong winds. Keep in mind that the roots of eremurus are shallow and they don't like being crowded or forced to compete with neighboring plants. Once midsummer arrives and the eremurus are dormant, it’s fine for other perennials to overshadow them.
Eremerus roots resemble starfish: a prominent crown encircled by long, fleshy roots. Handle the roots gently and plant them as soon as possible. Don’t be concerned if the roots appear spongy and discolored, but if they are completely dry it’s unlikely they will grow.
Dig a 6-8” deep planting hole that is wider than the roots. Make a mound of sand in the center of the hole and place the crown on top of the sand. Then refill the hole. It’s important not to plant too deeply. The crown should be just an inch or two below soil level.
Space the crowns 1 to 3 feet apart, depending on the ultimate size of the cultivar. After planting, mark the location of the crowns so you don’t accidently step on them.
In windy areas and with cultivars that are extremely tall, the flowers may need staking. When bloom time is over, you can cut the stems back to the base of the plant. If you want try letting the plants self-sow, allow the spent flowers to stay on until they drop their seed. Always wait until the foliage has completely yellowed before removing it.
Though eremurus dislike wet soil, they need consistent moisture in the spring when the plants are in active growth. This is also the best time to fertilize them, using a high potassium fertilizer.
If your eremurus become crowded and need to be divided, do it in late summer or early fall. Go slowly, taking extra care not to damage the brittle roots. Gently tease the crowns apart and replant them so the crown is only an inch or two below the soil surface.
In wet winters, eremurus are at risk of being damaged by waterlogged soil. Clear debris away from the soil surface and keep any mulch away from the crown of the plant.