Our late summer weather is bringing us cool mornings and the promise of a lovely fall. Soon it will be time to prepare our gardens for fall and winter by removing summer vegetable and ornamental plants, and putting in winter crops, pansies and other colorful winter plants.

Some of us have already started seeds in preparation for fall planting, and others look forward to fall plant sales.

Don’t give up on some of those summer annuals yet though because many will bloom until first frost.

You can give them a haircut by cutting them back by at least a third and up to a half. Give them a boost by applying a liquid fertilizer, and they will be rejuvenated with new growth in the cooler weather that is coming our way.

Pansies and other winter annuals should be planted by the middle of October so they can get some roots established before the cold winter weather hits.

Fall is a great time to add organic matter to your soil; a pansy bed should contain at least 25 percent composted material (soil amendments) mixed with your native soil.

Good soil amendments include your own compost, purchased compost or garden soil, well-rotted and composted manure, and soil conditioner. Mix the amendments into the top 6 inches of soil, and then you’re set to plant.

Remember to adjust your sprinkler system in the fall. While many of our sandy lawns and gardens require the application of 1½ inches of water per week in the hot summer, you can get by in the cooler fall with applying one inch of water per week.

Turfgrass care

Clemson suggests that no nitrogen be applied in this climate zone on any southern turf after Sept. 1. That means you should avoid the fall “weed and feed” products that are widely available.

If you are overseeding with rye or fescue that can be an exception (see next paragraph); look for a detailed lawn fertilization schedule by using the search function on Clemson’s online Home and Garden Information Center at www.clemson.edu/extension/hgic/.

An application of potassium (0-0-10 or 0-0-15) in mid- to late-September will enhance the cold tolerance of your lawn. Have your soil tested now to see if you have a potassium deficiency in your lawn areas.

Many Aiken residents overseed their lawn for winter, but note that Clemson does not recommend overseeding our southern turfgrasses.

Because centipede and St. Augustine are not completely dormant in our mild winters, any nitrogen fertilizer applied will encourage new growth in those warm season turfgrasses as well as the overseeded turf, and can result in the death of any tender new growth and cause winter die-back.

Overseeding Bermuda and/or zoysia is also not recommended because it will slow spring green-up by about three weeks.

In the fall, to control winter annual weeds, apply pre-emergence herbicides when nighttime lows reach 55 degrees to 60 degrees for four consecutive days.

On average, this is around Sept. 15. If you miss that application then use a post-emergence herbicide after your lawn has gone dormant (lost its green color) and the weeds are easily viewed.

Remember that cold temperatures reduce the effectiveness of herbicides. Consider delaying an application if temperatures drop below 50 degrees.

A preventative fungicide can be applied to your lawn in the late summer/early fall (now) to prevent fungus problems next year. If you have questions about caring for your turfgrass in the fall, give us a call at our office on weekday mornings at 803-649-6297, ext. 122.

September garden chores

It’s time to divide spring-blooming perennials like daylilies, iris and monkey grass (liriope or mondo grass). It’s best to divide spring-blooming plants in the fall and to divide fall-blooming plants in the spring.

How do you know when a plant needs to be divided? Most perennials need to be divided every few years, but when the center of a plant is dying out, it is definitely time to divide it.

Dig out the plant and gently pull the roots, bulbs or rhizomes apart; if necessary use a garden fork or knife to pry or cut the root ball apart.

Once divided you can place a portion of the plant back in its original location with newly-amended soil and either place the rest of the plant in another location in your garden or share it with a friend.

A favorite garden writer

Walter Reeves is a retired Georgia extension agent, author, and television personality who has a wonderful website (walterreeves.com) for gardeners here in the Southeast.

On the website you can sign up to receive his bi-weekly email gardening newsletter, keep yourself on track through the seasonal calendar, and read articles of interest to you.

Walter has also written several gardening books and has an active Facebook page. Gardeners love to learn about their favorite hobby, and Walter supplies professional and timely information.

The science of gardening

At least one-third of our food crops rely on honey bees for pollination. So remember that honey bees and other pollinators need water and nectar until they retreat to their hives if/when we have a harsh winter.

At our last lunch box lecture, Master Gardener Hank Smalling recommended these pollen-producing fall bloomers for our Aiken gardens: Mexican sage, pineapple sage, Anthony Parker sage, redneck girl sage, sunflowers, asters, confederate rose, knotweed (red dragon), tea olive and goldenrod.

Most people will not purposely plant goldenrod, but if you have a natural field of it then let it grow and feed the bees. For winter he recommended camellia, helleborus and rosemary.

Upcoming Aiken Master Gardener events

The “Meet A Master Gardener” team will be at the Aiken Farmers Market on Saturday from 8 a.m. to noon to answer your lawn and garden questions.

The next installment of our free monthly lunch box lecture series will be at 12:30 p.m. on Sept. 15 at Trinity United Methodist Church, 2724 Whiskey Road. The speaker will be South Carolina naturalist Rudy Mancke with a talk on “Natural Places to Visit in South Carolina.”

The lunch box lecture series is open to the public, lasts about one hour and requires no reservations.

Aiken Master Gardener volunteers are busy preparing for our large fall educational gardening event that will be held on Oct. 4. This event is held in conjunction with the City of Aiken’s fall festival at the Aiken Farmers Market and will include a small plant sale, composting and turfgrass demonstrations, activities for all ages and many other educational displays.

If you have questions about these events or any other lawn and garden topics, call the Aiken Master Gardeners at 803-649-6297 ext. 122; send an email to info1@aikenmastergardeners.org; or visit us weekday mornings in our office at 1555 Richland Ave. E.

Happy gardening!

Pam Glogowski moved to Aiken in 2001 from Janesville, Wisconsin, and has been an active master gardener volunteer since 2007.