When to Divide Hostas
By: Julie Day
Irene asks, “When can hostas be divided and transplanted?”
The best time to divide and transplant hostas is in August or September, about a month before your first frost date. Hostas respond well to early fall division because:
- Fall growth spurt: When the midsummer heat eases off and rains return, hostas often have a growth spurt. Dividing during this growth spurt will help them establish new roots quickly. If you’re planning to make tiny divisions (to turn one hosta into ten), fall is definitely the best season.
- Spring success: By next spring, the plant will be well established and will sprout more mature looking leaves, giving a better appearance.
Many gardeners prefer to divide hostas in spring, because it’s easier to see the clumps before the leaves get so huge. This may be more convenient, but keep in mind that spring divided hostas have some risks:
- Growth:Spring divisions often look scraggly the first year, because the stress of transplanting will stunt the leaves. If you must divide in spring, make very large divisions that leave a substantial clump intact.
- Health: Hosta divisions are also more susceptible to severe spring weather. Hostas put out leaves first, and roots second. If you interrupt the spring leaf burst, you’ll delay root formation for a month or more, leaving your new hostas vulnerable to the cool soil, drying winds, and unpredictable heat waves of spring.
Hosta Dividing Tips
Whenever you divide your hostas, keep these tips in mind:
- Plant Age: Hostas that are around three years old generally transplant best – they’re large enough to divide while not being too dense to cut apart.
- Heat and Drought: Severe heat and drought are dangerous to newly divided hostas. Keep them well watered, especially if the humidity is low.