I have two huge whirling butterfly plants and two lavender plants I need to either move or divide before next year. How and when should this be done?

­— Carolyn

The best time of the year to divide most perennials is right now.

I usually say late September through October is the best time to divide spring- and summer-blooming perennials such as the two you have.

But wait until the weather has cooled a bit. Doing it while it's still hot puts additional stress on the plant and occasionally leads to trouble.

You could do it early next spring, but doing it now often means you'll get some flowers next year, while dividing in the spring often means a summer without flowers as the plant re-establishes itself.

To divide them, dig the whole clump up and set it aside. Clean off most of the soil around the plant so you can better see it.

Cut out and discard any roots or portions of the clump that are dead, soft, or rotted. What is left can be cut into smaller pieces for replanting.

Most people cut an older perennial into two to six pieces, depending upon the plant. You want several sprouts or growth points along with some roots attached in each piece.

Avoid the temptation of cutting your mother plant into too small of pieces. You run the risk of losing them or creating weak plants that struggle to re-establish themselves.

To cut the clumps apart, you can use a large knife you don't mind getting dull, pruning shears or a good sharp shovel, which is what I often use.

Before replanting, take advantage of having access to the soil to work in some decomposed organic matter such as Soil Pep or compost.

Our soils need all the help they can get, and your plants will appreciate it.

You will probably end up with more plants than the current spot can hold. You can set them into other parts of your yard or give them to friends and neighbors or just add them to the compost pile.

The goal is to give the plant more space and to reinvigorate it. You're giving it a new lease on life.

Dennis Hill is the nursery manager at Bookcliff Gardens, bookcliffgardens.com. Send questions to Bookcliff Gardens, 755 26 Road, Grand Junction 81506, or email info@bookcliffgardens.com.

WATER TIP

Fall yard fertilizing — Fertilize your lawn with twice the usual amount of nitrogen just before you winterize your sprinkler system.

This will increase root depth and reduce disease problems next spring and summer.

The Drought Response Information Project (DRIP) is a collaboration among the valley's domestic water utilities and the CSU Extension Service to provide information about drought and the importance of water conservation.

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