Magazine article Sunset

Perennials Forever ... Free

Magazine article Sunset

Perennials Forever ... Free

Article excerpt

ONE QUICK WAY TO DOUBLE--OR even quadruple--the size of your perennial garden at no cost is to divide overgrown and crowded clumping perennials and bulb-like plants. Not only do you get new plants to fill the gaps in existing beds or to start an entirely new border, but dividing improves the health of an established plant so it will grow vigorously and bloom profusely.

In mild-winter climates, fall is the best time to divide spring- and early-summer-blooming perennials (in cold-winter climates, divide plants earlier in fall so the roots can get established before cold weather sets in). Late-summer- and autumn-blooming plants such as aster and purple coneflower can be divided in late fall or spring.


As clumping or bulblike perennials grow, they put out new growth around the center clump. Some plants--aster and astilbe, for instance--eventually turn woody in the center; this old growth becomes less vigorous or even dies. Divide; such clumps into sections, then discard unproductive growth and save only the healthiest parts of the plants.

Most perennials, however, don't develop a woody clump; you can simply divide the entire plant into sections and replant each section.

To survive, each division must have roots and at least one stem. While you can often divide a plant into dozens of sections, remember that the smaller the section, the longer it will take to establish, mature, and put on a good show of bloom. For best results, divide plants into fewer, larger pieces--unless you're dealing with a very overgrown plant (typical of agapanthus or red-hot poker) or you need a lot of plants to start a new garden.

How often you divide perennials depends on how fast the clumps expand. Some vigorous growers, such as fortnight lily (Dietes) and lamb's ear (Stachys byzantina), often need dividing every two to three years. Slower growers, such as bleeding heart (Dicentra) and peony, need dividing only every five years or so.

If a plant is blooming poorly, has a lot of dead wood in the center, or is cramped and pushing out of the soil, it's time to divide. If the plant appears vigorous and is blooming, then wait.


The day before dividing a plant, moisten the soil thoroughly so you can dig up the plant more easily. Use a shovel or spading fork to cut a circle into the soil around the plant--6 to 12 inches beyond the plant's perimeter. Getting large, overgrown plants out of the ground is often the toughest part of the job. With more delicate plants, be careful not to damage the roots.

Once the plant is out of the ground, gently tease some soil from the rootball (hose it from fragile roots). …

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