Masses of hostas intermixed with coleus can fill the void in your part shade landscape while adding a touch of color. Hosta blooms, which display in late summer to fall, increase the visual display of this perennial plant. Hostas do not need to be divided, but by dividing large plants, you can ensure its girth is not overpowering smaller hostas nearby. Better yet, dividing increases the number of hostas you have in your landscape at no additional cost. After dividing hostas, which is best done in the spring, you can keep them in posts to grow or you can replant the divided plants immediately.
Choose a location in part shade with good drainage. Till the soil down to a depth of at least 12 inches. Add six inches of organic matter and work that into the tilled soil. The organic matter can be compost, decomposed manure or crumbled leaves.
Dig a hole in the tilled area as deep and wide as the roots of the division. Place dirt in the center of the hole to create a cone around which to spread the roots. The top of cone should come up to about ground level.
Spread the roots of the division and center it on the top of the cone. The crown of the hosta division (where the leaves meet the roots) should be at ground level. Make the cone shorter or taller if necessary so the crown is at the proper level. Backfill the hole, pushing the dirt down with your hands as you fill the hole to force out air pockets. If you are planting several divisions, use the original hosta as a gauge for how wide the hosta will grow to determine the best distance apart to plant the divisions.
Apply 2 to 3 inches of mulch if desired. Keep the mulch about 2 inches away from the crown of the plant.
Water deeply after planting and continue to water deeply every seven to 10 days unless there is a saturating rain.
Fertilize, if desired, with a general granular or liquid fertilizer. Apply the fertilizer at ground level so none gets on the leaves. Fertilizer can be applied as frequently as the manufacturer suggests; however, discontinue use of fertilizer by August.