Most gardeners think of dividing hosta in the spring when gardening enthusiasm is at its highest. In practice, hosta can be divided at any point in the gardening year that the ground isn’t frozen, but there are times that are better than others. One of the drawbacks to dividing in the spring is that root growth won’t catch up with leaf growth for a while. This can lead to wilting of the plants because there isn’t the root structure in place to support the plant if we get a few hot days in the spring. This generally will not kill the plant, but may retard its growth for the season. Only the faster growing hosta should be divided in the spring.
Late summer or fall division is preferred by many, especially for the slower growing plants. The soil is warmer which promotes root growth. The plants generally have peaked in their appearance and are on the decline as the days get shorter, so the thought is that we will trade the less than perfect looking plants now for the promise of better looking plants in the spring. Fall divisions should be performed at least a month before the first expected frost. Also, they should have some of the larger leaves removed and should be mulched and kept moist.
Hosta are hardy and forgiving plants. Some gardeners like to divide their hosta by chopping through them with a spade. While this will work, it will place more stress on the plant.
The following steps should cause less stress.
- Dig around the plant with a spade to a depth of 8-10 inches
- Dig under the plant with your spade or garden fork and lift the plant out.
- Wash the soil from the plants to see where the best places to divide the plant are
- Cut through the crown with a sharp knife leaving 3 or more shoots per division. Do not cut any roots.
- Prepare the new planting area by adding some compost. If you are dividing in the spring, work a little balanced fertilizer into the soil, if you are dividing in the fall, wait until early next spring to fertilize.
- Make the hole slightly larger than the division and place the division in the new hole, being careful not to damage the roots. Plant the divisions at the same depth as they were growing. Carefully back fill and firm up the soil around the divisions.
- Water fall divisions well and mulch to conserve moisture. Spring divisions should be kept moist, but hold off on mulching until the soil warms up.
Dividing hosta helps the plants by keeping them from becoming over grown, but it also helps you by multiplying these versatile landscaping plants.