Dividing Daylilies

By Jeff Rugg

Q: Back in July, you said about daylilies, and I quote: “They … often bloom better if they are divided after about four years in the ground. Early fall is the best time to do this, so think of it as a job to do right after the kids go back to school.”

Well, the kids are back in school. How do I divide the daylilies? Mine have never been divided, and they seem to bloom OK.

A: The daylily rhizome sends up clusters of leaves. Each cluster is called a fan. The fans usually send up only one flower stalk a year, but some varieties send up a repeat flower stalk late in the season.

A few varieties, such as Stella de Oro, send up stalks on a regular basis. Each flower stalk could have a few to several dozen flowers.

Even though dividing every four years is often recommended for best blooming, many people have never divided their daylilies. Many varieties need dividing only once in five to 10 years, and many flower well for decades without being divided. A slow grower will only add a few fans to the clump each year, while a fast grower can add a dozen or more. If the clumps are planted close and start growing together so you can’t walk between them, then you may need to divide them.

For those of us who haven’t divided our daylilies in a long time, early fall is a good time to do so. Do it a month or more before your first frost is due and the plants will be well established before blooming begins next summer. If you run out of time, you can divide them in the early spring. Spring tends to be more hectic for gardeners, and planting new stuff is more important than dividing old stuff.

The fans of leaves can be cut back to six inches to make them easier to handle. Dig up the clump or just half the clump. If the soil is dry and comes off the roots easily, that’s great, but if necessary, you can wash them off with the hose. If the roots come apart easily, separate them into clusters of three or four fans by pulling them apart or with a sharp knife, if necessary. Using a shovel to cut the clumps apart will damage a lot of roots. Using two garden forks back to back and prying the clump apart can separate it with less damage.

If the plants won’t be planted right away, they can be stored in a cool, dry location. If they are going to be planted within a few days, keep the roots and remaining soil watered.

If you only dug up half the clump, fill the hole with a good composted soil mix so the plant can expand back into good soil. Plant the new clusters in holes big enough for the roots to spread out at the same depth as they were originally growing. Daylilies do best in full sun to partial shade and in soil that stays damp in dry weather and does not flood in wet weather. A balanced fertilizer such as 10:10:10 applied in the spring will be fine.

Depending on your needs, the clumps can be divided all the way down to single fans and their accompanying rhizome section and roots. Leaving several fans connected together will make for a fuller display of flowers next year. Smaller varieties can be planted 18 to 24 inches apart, and larger varieties 24 to 30 inches apart.

If you are interested in new daylilies, get “The Color Encyclopedia of Daylilies” by Ted Petit and John Peat, published by Timber Press. It has photos of thousands of daylilies, so I am sure you will find some that suit
your fancy.

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