Lawns
Most years, September is the perfect time to renovate the lawn or seed a new one. This is the preferred time as weeds are less likely to be a problem. The soil is warmer than it is in the spring. Grass seed germinates sooner. But freshly sown grass seed wants to be watered 2-3 times a day until germination, and this year water is in short supply; see Water restrictions below.
Fertilize established lawns early in the month to support renewed cool-season growth. Grass plants are actively producing roots and take up more mineral nutrients than at any other time of year.
Adjust timing on automated irrigation systems. As days get shorter and cooler weather arrives, turf will require less water. With regular rainfall, irrigation may not be needed.
Do not attempt to control crabgrass and other annual grass weeds now; they will die as cool weather and frosts occur. Decreasing the mowing height and collecting clippings will reduce the number of seeds available to germinate next year. A crabgrass pre-emergent herbicide, such as corn gluten, can be applied next spring when forsythia is in bloom.
Have your garden and lawn soil tested this month to see if lime is needed. Go to soiltest.umass.edu for complete information on taking and sending a sample to the UMass Soil Testing Lab. If needed, limestone is best applied in fall. The Library of Things at the Acton Memorial Library includes a soil testing kit with soil auger, sample bags, and directions.
Water restrictions: Now at Level 3
As of September 23, 2026, the Acton Water District (AWD) restrictions on non-essential outdoor water use have been relaxed from Level 4 to Level 3. The AWD website says: “Nonessential outdoor water uses that are subject to mandatory restrictions include lawn and landscape irrigation via aboveground sprinklers and automated irrigation systems… These activities are restricted to one day per week before 7AM and after 7PM. No outdoor water use is permitted on Mondays. Any violations will be subject to a fine of up to $200 per incident.” To see which day of the week applies to your property, refer to map on this page.
The AWD continues: “Please note that watering of lawns, gardens, and ornamental plantings using a handheld spring-loaded hose nozzle or watering can is permitted in Level 3 following the odd/even schedule. Even-numbered homes may water by hand on Tuesday, Thursday, and Saturday; and odd-numbered homes may water by hand on Wednesday, Friday, and Sunday. Limiting these activities to before 7 a.m. and after 7 p.m. is encouraged as a best practice. Watering via harvested rainwater, a private well, or other privately owned water source is exempt from mandatory restrictions.”
Perennials – Woody plants
Dead-leaf daylilies, astilbes, ferns and other perennials may have dried out in the extreme heat this summer. Keep up with weeding in the garden beds.
Divide perennials that are too large, have a dead spot in the middle, or older plants that are not blooming well.
Plant, divide or move early blooming perennials. The general rule is to divide spring blooming perennials in the fall and fall bloomers in the spring. Therefore, this is the time to divide Hosta (funkia), Hemerocallis (daylily), Dicentra (bleeding heart), Heuchera (coral bells), Pulmonaria (lungwort) and Paeonia (peony).
Transplant evergreens until the end of the month. Water these plants regularly until Thanksgiving so they have an opportunity to establish themselves.
Late summer flowering shrubs may be pruned if blooming is complete.
No longer apply fertilizer to your plants, so that they can harden off before frost.
Cut down and dispose of plants that are infected with powdery mildew. The fungus that causes powdery mildew overwinters on infected leaves. Disposing of those plants now can help reduce recurrence of the disease next year. Do not compost infected leaves.
A sunflower stands tall in the sunlight
Photo: AM Testarmata”
Bulbs
Begin planning for fall bulb planting of spring flowering bulbs. The “minor bulbs” are those for small, early-blooming plants. Shop now for spring bulbs to get the best selection.
Rabbits, squirrels, and chipmunks love tasty tulips. Use a sprinkle of blood meal or the repellent of your choice when planting, to deter them. For particularly pesky critters, use chicken wire to fence the area. Daffodils, alliums, and hyacinths are deer and rodent resistant.
Dig up summer bulbs, tubers or rhizomes of plants such as: gladioli, tuberous begonias, dahlias, caladiums and cannas. Allow them to dry, cut off the leaves, and store them in mesh bags in a dry, cool, airy space. Most unfinished basements will work.
Other garden hints and trivia
Goldenrod is not responsible for the sniffling, sneezing, runny nose and watery eyes associated with hay fever and allergies. It is falsely accused because it flowers at the same time as many other annual weeds.
Many evergreens lose their older needles (the inner needles). This is normal and is most noticeable on white pine and arborvitae. Look at other trees to see if this is also occurring on them.
Bring houseplants back indoors as nighttime lows start to approach the mid-40’s. Before bringing houseplants inside, check carefully for pests. Aphids, whiteflies, and spider mites are all common pests that may hitchhike indoors where they will eventually become a problem. Adjust plants slowly to the new conditions. Avoid overwatering after the plants return indoors.
Check for yellow jackets and bald-faced hornet nests before pruning or shearing. Strike the hedge with a long-handled rake and carefully watch for flying wasps. Ground wasps can also be a problem. Spray them in the evening when wasps have returned to their hole.
Judy Dembsey is chair of environmental education for the Acton Garden Club.
