The process for planting hostas is not much more different than any other plant. The planting hole should be dug at least a foot deep. The width of the hole should be one and a half times the expected mature size of the clump. Check with the nursery or web site where you purchased your hosta for the plants expected mature size. Generally, hosta roots grow and spread horizontally, so a large wide hole is best. When planting hostas that are in a container, carefully remove the plant from the container. Sometimes the roots may be bound to the container. Tapping the container sides should loosen the roots from the pot. If the roots are difficult to loosen, it may be necessary to cut through some of them, make several vertical cuts in the routable. Shake the excess soil from the roots and do not use potting soil in the planting hole.
When planting hostas in the selected planting hole, take care to plant it at the same level as it grew in the container. The area where the leaves and roots meet should be at ground level. Soak the root zone thoroughly with water to remove dry pockets and air pockets in the surrounding soil.
Hostas can also be purchased barefoot. Planting hostas that are barefoot require a few extra steps. Before planting, soak the roots (barefoot means no soil) in tepid water for about 30 minutes prior to planting. The soaking should hydrate the roots before they are planted. Form a small cone in the bottom of the hole and then spread the roots over the small cone area and then add the soil. Water thoroughly to collapse the soil around the roots and to remove any air pockets.
Dividing hostas is easily achieved. Most home gardeners will propagate their hostas by division. Hosta division should be done when no shoots are growing from the center of the mature clump as this bare area detracts from the appearance of the plant. Dividing hostas this way will improve the plants appearance. Lift the entire hosta clump and wash the soil from the roots to make it easier to see where to cut and divide the clump. Use a sharp knife to make the cuts for dividing the hosta. Place the divided plants in their planting holes and keep them well watered for the first two weeks.
Spring is a good time for dividing hostas because the new shoots are only a few inches high and the leaves have not expanded. Spring division may cause leaf wilting on warm days, since the roots have been reduced in size or they were cut while dividing the hosta.
The month of August is also a good time for dividing hostas. The warm soil and humid weather promotes better root growth. The divided plants can get established before winter sets in. The hot weather usually experienced in August will create a high demand for water. Keep the plants very moist for the first two weeks after plant division.