September Garden To-Do List: What to Tackle This Month

September is one of the best months of the year to work in the garden. Cooler temperatures make outdoor projects more comfortable, while warm soil helps newly planted trees, shrubs, and perennials establish roots before winter.

It is also an important transition month. A little attention now can improve fall color, strengthen lawns and landscapes, and set the stage for a healthier garden next spring.

Here are some of the most important garden tasks to tackle this September.

1. Keep Planting

Do not assume the gardening season is over. September is an excellent time to plant many trees, shrubs, perennials, and ornamental grasses.

The combination of cooler air and warm soil encourages root growth without the stress of summer heat. Just remember that new plantings still need consistent watering while they become established.

If there is a section of your landscape you have been meaning to improve, fall can be an ideal time to get started.

2. Refresh Tired Containers

Summer containers can start looking a little worn by September. Remove tired or declining plants and refresh pots with fall favorites such as:

• Garden mums
• Pansies and violas
• Ornamental kale and cabbage
• Ornamental peppers
• Grasses
• Heuchera and other colorful foliage plants

You do not necessarily need to replace the entire container. Sometimes adding two or three fresh plants is enough to give it a completely new look.

3. Give Your Lawn Some Attention

Early fall is an important time for lawn repair. Cooler temperatures and more consistent moisture create favorable conditions for grass growth.

September lawn projects may include seeding thin areas, overseeding, aerating compacted soil, controlling weeds, and applying an appropriate fall fertilizer.

Repairing summer damage now can make a noticeable difference next spring.

4. Keep Watering

Cooler weather can make it easy to forget about watering, but plants can still become stressed during dry periods.

Pay particular attention to anything planted this year, including trees, shrubs, and perennials. Established gardens may also need supplemental water when rainfall is limited.

Deep, thorough watering is generally better than frequent shallow watering.

5. Divide Overgrown Perennials

Some established perennials benefit from being divided every few years. September can be a good time to divide plants that have become crowded, are producing fewer flowers, or have developed an empty area in the center.

Dividing plants can improve their vigor while also giving you additional plants to use elsewhere in the landscape.

6. Continue Deadheading — But Leave Some Seed Heads

Remove spent flowers from annuals and some perennials to keep gardens looking tidy and encourage additional blooms.

However, there is no need to clean up everything. Seed heads from plants such as coneflowers and black-eyed Susans can provide food for birds and add winter interest to the garden.

A slightly less aggressive fall cleanup can also provide valuable habitat for beneficial insects.

7. Start Thinking About Spring Bulbs

Tulips, daffodils, crocus, alliums, and other spring-flowering bulbs are planted in fall.

September is a good time to decide where you want spring color and begin purchasing bulbs while the best selections are available. Planting typically takes place once soil temperatures begin cooling.

A little planning now can produce a dramatic display next spring.

8. Add Fall Color to the Landscape

September gardens do not have to look tired. Many perennials, ornamental grasses, shrubs, and annuals reach their peak late in the season.

Look for plants with colorful foliage, berries, seed heads, and late flowers. Mixing several types of plants can keep the landscape attractive well beyond the traditional summer gardening season.

9. Start Light Cleanup

Remove diseased foliage, damaged branches, weeds, and declining annuals as needed, but avoid cutting the entire garden down too early.

Many plants continue providing color and structure well into fall, and leaving some stems and seed heads can benefit wildlife.

Major cleanup can wait until later in the season.

10. Walk the Garden and Make Notes

September is also a good time to evaluate what worked this year.

Ask yourself:

• Which areas need more color?
• Are any plants becoming overcrowded?
• Where could you use more shade or screening?
• Did certain areas stay too wet or too dry?
• Are there spots where a new tree or shrub could improve the landscape?

Making those observations now makes future garden planning much easier.

September Is Still Gardening Season

Fall is not simply the end of the gardening year. In many ways, it is one of the best opportunities to improve your landscape.

Whether you are repairing the lawn, refreshing containers, planting trees and shrubs, adding fall color, or planning ahead for spring, there is still plenty to accomplish.

Stop by Bru-Mar Gardens for plants, seasonal color, fall gardening supplies, and advice to help you make the most of September in the garden.

September Garden FAQ

Is September too late to plant?
No. September is an excellent planting month for many trees, shrubs, perennials, and grasses because cooler temperatures reduce stress while the soil remains warm enough for root development.

Should I stop fertilizing my plants in September?
Avoid pushing tender new growth on many landscape plants late in the season. Lawn fertilization, however, is often an important part of fall lawn care. Ask the Bru-Mar team about the right product for your particular plants or lawn.

How often should newly planted trees and shrubs be watered?
Water deeply and consistently while plants establish, adjusting for rainfall, soil conditions, and temperature. Newly planted material should not be allowed to completely dry out.

Should I cut back all of my perennials in fall?
Not necessarily. Leaving selected stems and seed heads provides winter interest, bird food, and habitat for beneficial insects. Diseased plant material should generally be removed.

When should I plant spring-flowering bulbs?
Spring bulbs are planted during fall once the soil begins cooling. Shopping earlier gives you the best selection and plenty of time to plan your display.