Garden Update - September

(Updated: Aug. 26, 2025, 12:41 p.m.)
Purple hyacinth beans and moonflower
Purple hyacinth bean and moonflower vines are at their peak in September. Plant together to highlight the purple and white flowers. Collect seeds from both vines after the first frost in October and save them in a paper sack for next year.

Plants in Flower

Crapemyrtle, Rose-of-Sharon, Dahlia, Canna, Ginger Lily, Chrysanthemum, Spider Lily, Fall Crocus, Liriope, Sedum, Asters, Goldenrod, Joe Pye Weed, and summer annuals

What to Fertilize

Fertilize lawns (see below).

If you are trying to push trees or shrubs to grow as vigorously as possible, you can fertilize with 5-10-15 fertilizer this month.

What to Plant
  • September is a good time to set out landscape plants. Shop early to find the nicest shrubs. When planting containerized plants, try to be certain to disturb or “open up” the plants’ root ball.
  • Set out new chrysanthemum plants this month.
  • Plant pansies to add color to your yard in the autumn, winter and spring months.
  • Groundcovers will become well established if planted now.
  • Transplant any evergreen trees or shrubs that need moving this month.
  • Plant the following fall vegetables in September: mustard, onion, radish and turnip. If you do not have a fall vegetable garden plant legume cover crops like crimson clover or hairy vetch. Wait until October for small grains.

viburnum
What to Prune
  • Do NOT prune shrubs in September or October.
  • Remove “weed” or unnecessary trees from your landscape.
  • Root prune any trees or plants you plan to move next spring.

Pest Outlook
  • Scout the following landscape shrubs for the following insect pests: arborvitae, hemlock and juniper(spider mites), azalea and pyracantha (lace bug) and euonymus (scale).
  • Scout for peach tree borer on your nectarine and peach tree trunks.
  • Scout roses.
  • Scout fall vegetable plants. Insects and diseases are more severe in the autumn.
  • Control woody weeds by spraying the recommended herbicide.

fesuce
Lawn Care
  • Scout for fall armyworms now.
  • Aerate, lime, fertilize and overseed tall fescue and bluegrass lawns this month.
  • Remember to mulch the new grass seed areas with wheat or barley straw.
  • Keep watered.
  • Do NOT fertilize zoysia now.
  • Homeowners can apply an insecticide for lawn grubs in early September if not completed in August.

Propagation
  • Spring flowering bulbs can be divided and replanted this month.
  • Daffodils will be the bulbs that most likely need this consideration.

late summer flowers
Specific Chores
  • Clean up garden sprayers and lawn equipment if not in use.
  • Prepare house plants to reenter your home. Check them carefully for insect pests.
  • If you do not have a fall vegetable garden, it is a good time to chop, till, burn or discard dead vegetable plants.
  • Look for spring flowering bulbs to plant in October.
  • Purchase locally grown apples.
  • You can get last year’s poinsettia to flower by placing it in total uninterrupted darkness for 15 hours a day, starting the last week of the month and continuing until colored bracts appear. Give them plenty of sunlight during the day.
lawn care calendar
Taking care of your lawn does not have to be difficult. Here is a simple lawn care calendar.