Divide summer- and fall-blooming perennials, such as Shasta daisies and chrysanthemums, now to promote better bloom later this year. Wait until autumn to divide spring-flowering perennials, such as candytuft, bleeding hearts, and creeping phlox.
After the danger of a hard frost is past, prune fall-flowering clematis back to the strongest stems. Wait to prune spring-flowering clematis until after blooming has finished. After pruning, broadcast fertilizer on the soil beneath the plants, scratch it in, and water well.
Prepare New Beds
When the soil is dry enough to work, till the soil to a depth of 6 to 8 inches. Spread a 3-inch-thick layer of compost or well-rotted manure over the bed and dig it in, then rake the bed smooth. The bed is now ready to plant once the weather warms.
Plant bare-root plants of asparagus, horseradish, and rhubarb. Asparagus crowns are best planted in a 1-foot-deep trench that's filled in as the plant grows. Plant in a sunny location in soil amended with compost. Keep the area well watered and weed free this summer for best growth.
The best control for little bittercress -- one of the earliest weeds to start growing in spring -- is to go on daily patrols, removing the small whorls of leaves before the plant has a chance to produce a flowering stem. If allowed to flower, the plant forms seeds that are literally catapulted from a pod the minute it's touched.