What Time of the Year Do You Divide Hostas?

Time

• The best time to divide hostas is in the spring, according to the University of Wisconsin Extension. Wait until the ground thaws enough to be easily worked, and plan for a day when you will have enough time to immediately replant the divided hostas. Wait until the new leaves are between 1 and 3 inches tall. At that size, they are easy to handle, but the leaves aren't so large that you will damage them. If they are damaged, simply clip them off before replanting the plants.

Method

• Gently loosen the soil around the plant clump, and lift it out of the soil with a garden fork or spade. Shake the loose soil from the roots and lay the clump on a flat surface. Cut apart the roots with a sharp knife or pruning shears. Cut cleanly through the root ball, and ensure each new clump has two or three sprouts on it.

Culture

• Plant the divided clumps in moist, loamy soil in a location that is exposed to afternoon shade. Some cultivars can tolerate more sun than others, but all do best if shaded from the hot, direct rays of the afternoon sunlight. Plant them at the depth they were before and surround the plants with 2 inches of mulch to help retain moisture in the soil.

Considerations

• Although spring is the best time of year to divide hostas, they are hardy enough plants that they can be dug up and divided any time, according to the Clemson Cooperative Extension. Plants divided in the summer and replanted need careful irrigation, however, if the weather is hot, and the ground may be too hard to easily divide hostas in the winter.