DECEMBER GARDENING SPECIFICS . . . : Dividing perennials:

Each year a typical perennial gains in size by growing new roots and stems usually around the perimeter of the previous year’s growth. Eventually these clumps get too big for their space in the garden. Growth and flowering become less vigorous due to overcrowding and competition for water and nutrients. Each clump (root division) is actually a plant in itself or is capable of becoming a new plant. To keep plants such as agapanthus, day lilies, moraea (also called dietes), Shasta daisy, asters, coral bells, columbines and lamb’s ears healthy and producing abundant flowers, it is necessary to divide them every two or three years. Dividing restores plant vigor and appearance.

When to divide: A general rule would be to divide plants well after blooming, giving them plenty of time to become established before the next growing season. Early to mid-fall is an ideal time while plant growth slows down, days are shorter and warm soil temperatures encourage root growth.

Determine exactly where you want to replant the divisions.

Prepare the soil adding necessary amendments and a mild fertilizer/soil activator.

Carefully dig up entire root ball. Usually you can pull on the root mass and clearly see individual plant clumps, rhizomes and tubers. These may pull apart easily or need to be cut apart carefully if it is not clear to you which part of the root ball forms a clump. Divide the plant by cutting medium to large pieces with healthy looking foliage and roots.

Cut off any old or damaged roots and leaves once you’ve divided the plant. Cut off some of the outer leaves on each clump to compensate for root loss. Cut the remaining foliage back a bit and plant new divisions at once. Water slowly and thoroughly so entire area is saturated. Source: Cristin Fusano, Horticulturist/Merchandise Coordinator, Roger’s Gardens and Sean Cincotta, Horticulturist, Sherman Gardens.