It's preferable to divide hostas in the late summer and early fall, roughly 4 weeks before first frost.
Dig all around the hosta clump and, using a garden shovel or fork, pop the clump out of the ground. Rinse as much of the old soil off as you can without damaging the roots and then move your hosta to its new home. Beware, hosta clumps are heavy! If you’re thinking about dividing your plants, now’s the time to do it. If your hostas are too large to lift out of the ground, use your shovel to cut the clump into divisions. Carefully dig out the sections and replant them. Here's a hint: Many gardeners find that it's easiest to divide hostas using a garden fork or flat spade. When to Divide Hostas. The best time of year to divide hostas is in late summer (August or early September). But, don't worry if you forget: You can divide hostas anytime from spring to fall. The best time to transplant hostas is in the spring, but that’s really because it’s easier on you, the gardener, than on the transplant. Hosta plants always need plenty of water and the trauma of transplant, no matter how slight, increases that need. 1. Choose the right time of year. While many gardeners choose spring for time to move and divide plants, it can have a negative effect on the plants, especially in hotter climates. It's preferable to divide hostas in the late summer and early fall, roughly 4 weeks before first frost. Hostas are fairly tough plants, though, and can be divided at any time during the growing season if you carefully replant, water, and mulch the divided clumps. How to Divide Hostas. If your hostas aren't too large, dig out the entire clump. One way to do this is to dig around the clump in a circle, then use your shovel like a lever to lift the clump out of the ground.
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when can i separate my hostas