“September days have the warmth of summer in their briefer hours, but in their lengthening evenings a prophetic breath of autumn.”

— Rowland E. Robinson

Fall Perennial Chores

The fall is a great time to plant, transplant, and divide perennials. Here are a few tips to help you maintain your perennial gardens:

• Divide spring blooming perennials in the autumn. Later season bloomers can be divided in the spring. 
• If perennials start to die from the center out, it may be time to divide them. This is very common in plants like hostas and ornamental grasses. 

• Cut perennials back to 6 inches before transplanting.

• Aim to do your planting and transplanting 4 to 6 weeks before the first frost in order to give your plants enough time to settle in before the ground freezes.

• Newly transplanted perennials should be adequately hydrated and monitored until the ground freezes. Plants should get one inch of water per week. If rain is not meeting that minimum, supplemental water will be needed.

• Plant spring bulbs at this time too, including daffodils, tulips and hyacinth. 

Perennials

How and When to Divide Perennials

Fall Foliage Predictions are Here!

The beauty of fall leaves here in New England is undeniable, and while many of us are hanging on to the last days of summer, the changing of leaves will be here sooner than we realize!

Some sources are predicting a slightly earlier autumn change of leaves this year. And some of us have already noticed early leaf drop in our trees and shrubs at home from a stressful growing season. Weather events, environmental pressures, and the natural physiology of our beloved trees all factor in to when, why and how the leaves change colors each year. Know what to look out for so you can plan your leaf peeping accordingly!

CT DEEP Fall Foliage Report

2025 Fall Foliage Prediction Map

How Weather Affects Fall Colors

Fall Colors: A lesson in Color Theory and Chemistry

 Hope for Biologic Control of Spotted Lanternfly

In the late summer/early fall, we start to see Spotted Lanternfly moths flying around, bringing a heightened awareness to this invasive pest.
As research continues, there are promising findings that native species may be starting to find and prey on the Spotted Lanternfly. While findings are still preliminary, many of the beneficial predators identified have already been found to benefit our gardens with other common pests.

Promoting a healthy garden ecosystem, removing the Tree of Heaven host plants, and regular scouting are still the best methods for control at this point, but keep an eye out for future findings!

Natural Insect Predators May Serve as Allies in Spotted Lanternfly Battle

Detection of Spotted Lanternfly by Bats

Spotted Lanternfly Resources for Connecticut

Native Plant: Fringed Gentian

Mother Nature likes to save her best flowers for last.

Fringed Gentian (Gentianopsis crinita), one of New England’s most beautiful wildflowers, makes its appearance from late August to October in wet meadows and fields, on stream banks and in moist open woods. It's one of the last native wildflowers to bloom each year in the Northeast. The flower is easily identified by its fine fringed petals and striking blue to purple-blue color. 
 

Learn More About Fringed Gentian

The Connecticut Native Perennial, Tree, & Shrub Availability List

Word from the WiSE

Women in Soil Ecology, UConn Student Chapter

Knowledge to Grow On

Upcoming Events and Things to Do

• 39 Things to do in Connecticut this September

• September is the peak of Fair Season in Connecticut! 

From late August to Mid-October, hundreds of thousands of Tree Swallows near the mouth of the Connecticut River converge at dusk and form large clouds from which they descend into the communal roost along the shoreline. Just west of the mouth of the Connecticut River in Old Lyme is Goose Island,  seventy-five acres of uninhabited reeds making it a mecca for the Tree Swallows.  There are many ways to observe this phenomenon. By boat or kayak. It is a spectacle that no one who is interested in birds should miss.

Educational Opportunities & Workshops

September Gardening Tips

• Lawn seeding, whether it's renovation, repair, or spot seeding should take place between August 15th and September 15th

• Mid to late September is a great time to add accent plants, like vivid mums and starry asters, that will provide autumn colors in the landscape. Use them along with cool-colored ornamental cabbages and kales to replace bedraggled annuals in containers as well

• Visit a local nursery or garden center and select spring flowering bulbs to add to your gardens. Plant the bulbs among perennials, under trees and shrubs, or in larger groups for a splendid spring show. Choose colors that complement other spring flowering plants as well as nearby plantings. Work a little Bulb Booster or 5-10-10 into the bottom of the planting holes.

• Examine houseplants carefully for insect pests before bringing them back inside. Give them a good grooming if necessary. You may want to spray plants with insecticidal soap after hosing off the foliage. Let the plants dry first.

• As tomatoes end their production, cut down plants, pick up any debris and put dead/diseased plant parts in the trash or take to a landfill. Many diseases will over-winter on old infected leaves and stems so these are best removed from the property.

• If pesky seedlings of woody plants, such as maple, elm or hackberry are found growing in your yard, remove them as soon as possible so they won’t take over gardens and other landscape plantings.

• Continue to water any new tree, shrub, or perennial plantings until the first hard frost if fall rains are scarce.

• Limit herbaceous plant material located a few feet away from the house to eliminate hiding places for insects and mice that could wind up indoors as temperatures plummet.

• Continue to turn and moisten compost piles to speed decomposition.

• Scout for and remove bagworm egg masses from evergreen shrubs to eliminate the spring hatch from over-wintered eggs. 

• Late season cabbage and beets can stay in the garden until a light frost for best flavor. Some root crops, including certain varieties of beets, carrots and parsnips, may be left in the ground for storage. Wait until temperatures drop and growth stops and cover with a thick layer of straw or leaves. Harvest as needed during the winter. This may not be an option in areas with heavy vole populations.

This Month’s Newsletter Contributors: 
Heather Zidack, Pamm Cooper, Marie Woodward, Nora Doonan