When should I divide my maiden grass "Gracillimus'?

There's an old saying among gardeners: Divide spring-flowering perennial plants in fall and fall-flowering perennials in spring. The same is true for Gracillimus, commonly called maiden grass.

Division is usually done when a plant has grown to considerable size and needs better spacing. It may also be needed to promote optimal health. If roots at the center of the plant have begun to die, they should be removed to make way for new roots and to eliminate the potential of diseases. Most ornamental grasses that bloom in the fall should be divided in the spring when there is time for roots to develop and grow.

After the first freeze, the foliage and seed heads of showy ornamental grasses can be left in place to extend the perennial garden's season as well as to provide shelter for birds through the winter.

I purchased a bag of bulbs, and the instructions say to place them in the refrigerator for six weeks before planting. Do I really need to do that in our area? I've never done it before and had great spring blooms!

The term "stratification" means the breaking of dormancy in seeds or bulbs. Most bulbs have simple stratification needs, either cold, warmth, moisture or some combination. Most bulbs purchased for planting in the fall will have been stratified by the growers. Our own natural freezing and thawing cycles likely will be sufficient to cause the bulbs to sprout in the spring. Still, it is always best to follow label directions carefully on packaging.

My mums have stopped blooming in my flower pots and I want to plant them in the garden. Can I divide them now before I plant them?

Chrysanthemums are best divided every two or three years in the spring. Even though dividing now after bloom would not disturb the formation of flower buds, the onset of cold weather and our first freeze could further stress the roots of recently divided plants.

My butterfly bushes are still in bloom. Should I continue dead-heading the flowers to promote continued blooming or prune them back for winter?

Butterfly bushes, or buddleias, produce beautiful blooms that attract hummingbirds and butterflies all summer and fall. It is a great idea to prolong blooms by dead-heading until first frost because, unlike roses that need to form hips to prepare for winter, most flowering perennials and annuals will bloom fine until dieback from cold.

For pruning back the tall branches, it is best to wait until early spring, before new buds begin to form. This will prevent dieback of new growth. Buddleias, which can grow to 12 feet tall, can be pruned to one third of the bush or occasionally down to 8 inches from the ground. Leaving brown branches on most perennials during the winter provides some protection for the roots and crown from drying winds and cold temperatures.