When to Separate Hosta Plants

Hostas range from a few inches to more than 4 feet in height.

Hosta, available in a range of colors, forms and sizes, is valued for its foliage and ability to provide interest to the landscape, even in shady areas where few plants will grow. Like most perennials, hosta benefits from occasional division. The result is a healthier, more vibrant plant.

Why to Divide

Dividing hosta is restores a mature plant to vibrant, vigorous growth. In time, the center of mature plants becomes woody and unproductive, while the outer leaves are scruffy and unattractive. Divide your hosta when the plant looks unattractive or outgrows its boundaries. Division is easiest and most inexpensive way of creating a new plant from a mature plant.

When to Divide

Although hosta can be divided at any time in the growing season, early spring is ideal. The shoots have begun emerging but and the plant is not in full leaf. The soil will be moist and cool. Late summer when the plant begins dying down is also a good time. If you divide your hosta in late summer, allow at least 30 days before the first expected hard frost in your area, as the roots need time to settle before freezing weather. Hosta can be divided during the heat of summer, but the job is more difficult and the plant needs extra care and plenty of water to promote rooting.

How to Divide

Use a shovel or garden fork to dig up the entire plant. Rinse the roots with a garden hose, so you can see the natural divisions, and then cut the plant into smaller sections with a sharp knife. If the hosta is large, leave the plant in the ground and use your shovel to dig an outer section. Don't make the divisions too small, as each division needs a healthy root system. Plant the division immediately in soil that has been amended with compost.

Care After Division

Water the divided hosta plants immediately after planting, and then spread 1 to 2 inches of organic mulch around the plant. Mulch, such as shredded bark keeps, the soil cool and moist while the roots become established. Keep the soil moist for at least two weeks after dividing your hosta. Thereafter, give your hosta about an inch of water every week during warm, dry weather. Hosta benefits from a feeding in early spring, using a balanced, slow-release fertilizer.

References

• Washington State University; Propagation of the Hosta: Kurt Easterday
• University of Minnesota: Dividing Hosta Plants