Early May is the time up north to divide overgrown clumps of daylilies, Shasta daisies, garden chrysanthemums, hardy perennial asters, perennial phlox, physostegia, plantain lilies (funkia), lythrum, garden heliotrope and speedwell (veronica).
It is especially important to divide garden mums that have survived the winter. Small divisions of the clump containing a stout sprout and a good piece of root produce better plants and more abundant blooms.
Garden chrysanthemums are not hardy perennials in the North. They do not come through the rugged winters like peonies, iris, and other hardy garden perennials. Some winters they survive almost 100% and other winters only a small percent come through alive.
New plants should be secured and planted early in May in order to get maximum growth and flowering. Later plantings result in smaller plants and fewer flowers.
This also is a good time to plant regal lilies and all of the summer and fall flowering varieties of hardy garden perennials. Spring flowering varieties are better planted in late summer or early fall. Gladiolus corms and dahlia tubers are planted in early May.
Toward the end of the month, window boxes and planters in sunny locations are stocked with appropriate plants such as petunias, geraniums, lobelia, sweet alyssum, and verbena. Those located in shady places are planted with tuberous begonias, caladiums, ivy and patience plants (impatiens).
For best results use new soil each year in window boxes and planters. The soil should be a porous, loamy type enriched with a complete fertilizer. There should be a drainage zone beneath the soil consisting of coarse gravel and or broken pieces of flower pots, also drainage holes in the bottom to allow moisture from rains and watchmaking to escape.
Water-logging of the soil would be sure death to the plants.
Ready for Crabgrass
Pre-emergence crabgrass and bug killers are applied to lawns infested with this most difficult to combat weed just like also with the indoor plant pests like the plant bugs.
Also, along toward the end of the month set the lawnmower to cut at two inches and mow the lawn more frequently, at least once a week or every five or six days. The higher grass will shade the crabgrass seed and cut down on its germination.
Leave the grass clippings on the lawn where they will disintegrate and supply a small but significant amount of protection for the turf and eventually contribute humus or organic matter.
As soon as the days get warmer, and the dandelions are making rapid growth, they should be sprayed with an approved weed killer.
Be sure to choose a calm day for application because the slightest amount of mist from the spray could damage garden flowers, trees and shrubs.
If possible, do spot spraying of dandelions, plantain and chickweed, and repeat applications within 10 days for control of the latter two weeds. If necessary, spray a third time.