Summer’s end finds this gardener hard at work preparing the garden for fall …taking inventory of what worked and what fizzled; cutting back any plant that has finished blooming or is diseased; and preparing the beds to receive new perennials.

I am taking advantage of the cooler September weather to divide overgrown spring and summer blooming perennials such as black-eyed susans, daylilies, peonies, Asiatic lilies, moss pinks and yarrow. Dividing these overgrown perennials will result in healthier plants and provide me with free plant material to fill in bare areas in my garden beds.

Dividing and replanting the divisions of black-eyed Susans, peonies and moss pinks is relatively easy; you simply cut into the crown of the plant with a shovel edge and dig up foliage and roots for replanting.  When dividing daylilies and Asiatic lilies the gardener should first cut back foliage by half and remove the dirt from the roots of the plant.

Daylily roots can be very fibrous and tough, requiring a sharp shovel or knife to break apart the mass of the root. Remove the old center and plant divisions of the roots that are about 6 to 8 inches across.

If you have shrubs you need to transplant, autumn is also the perfect time to do this — the roots of the plant will have time to become established and the plant will have a chance to settle into its new site before the first frost.

All this digging in the garden provides a good opportunity to dig up and store tender bulbs that need to overwinter in the garage or greenhouse, such as dahlias, cannas, tuberous begonias and caladiums.

September is also an opportune time to end your houseplants’ summer break. Houseplants need to be transitioned from the warm temperatures and daylight of outer garden beds or patios to a porch or semi-shady area where they can be acclimated to the lower light levels in your house. Check for ants or other outdoor pests before taking the plant indoors—a steady stream of water from a hose will often rinse these pests from the pots and prevent a home invasion as they winter indoors.

Although I have done away with my lawn, September is the month to make lawn improvements. Aerating and reseeding (or overseeding) is best done now, because the grass seed is able to sprout and grow without having to compete with annual grass weeds that sprout in the spring. The grass that develops from overseeding in the fall will have a chance to form a dense mat, leaving less room for weeds to sprout in the spring.

This diligent effort of cleaning up, cutting back and digging up the garden reveals the garden in its simplicity, and the gardener can now enjoy the opportunity to purchase and incorporate new plants. I have begun to scour the recently arriving garden catalogs for spring blooming bulbs (a subject for an upcoming column) — it’s time to order bulbs for planting in October and November. 

Finally, you might want to check out the Fall Garden Day from 9 a.m. to 3 p.m. Saturday, Sept. 22., at Green Spring Garden Park. Savvy gardeners arrive by 8:30 a.m. to get a choice parking spot and browse the vendors before the sale opens. Lots of local growers will be on hand to offer perennials, annuals, shrubs and trees for sale and most are happy to offer advice on choosing and growing plants in this area.

In addition to acquiring plants, you can enjoy great food, a program featuring live raptors, a monarch butterfly program and a silent auction to benefit the horticultural programs provided to the public by Green Spring Garden Park. I too will be there, filling up my little red wagon and enjoying a picnic on the lawn. I hope to see many of you there as well.

Eleni Silverman is a Master Gardener, Vice President of the Belle Haven Garden Club, Chair of the Landscape Committee at Thomas Jefferson High School for Science and Technology and author of the garden blog "Belle Haven Garden Maven." She is sole proprietor of The Well Tended Garden, providing garden grooming, coaching and design.  She admits to a fascination with all things gardening, believes even compost is engaging, and will eagerly discuss the relative merits of leaf mold versus hardwood mulch.