After a nice, hot summer and productive growing season, gardeners are winding down by the time that September rolls in. While warm weather is still hovering around, days are getting shorter and brisker mornings and cooler nights are becoming more prominent.
September gardening tends to shift as annual plants are slowing down, summer veggies give their last push to finish off production, and the temperatures are dipping.
Keep your gardens growing strong with some tips from our September Garden Checklist Zones 6-8. With a little bit of upkeep, fall planting, and planning, you can transition into fall with ease.
September Garden Planning & Reflection
It’s time to jot down the successes and shortcomings of this garden season and start developing goals for next year. We’ve highlighted some planning essentials that will help you grow and excel even more as a gardener.
- Grab your garden journal and make a note of high-performing and underwhelming plant varieties. Add your favorites to your list to buy seeds or plants for next year.
- Make some notes in your garden journal about the weather and how it impacted your garden this year. Were there any significant storms, droughts, or heavy rains?
- Decide which spring flower bulbs to plant this fall and buy them from garden centers when the selection is at its best.
- It’s not too early to acquire your seeds for spring if they are available.
- Sketch and/or photograph your vegetable garden layouts and keep them in your garden journal. This way, you will know how to rotate your crops for next year.
- Think about ways to add color and draw beneficial pollinators to your fall gardens. Consider planting nasturtiums, marigolds, asters, cosmos, mums, and anemones.
- Plan out your fall flower planters. Summer blooms are fading, but there are many opportunities to add color and visual interest to your landscape. Try pairing some fall showstoppers like heuchera, mums, asters, ornamental cabbage, and variegated ivy.
- Make a note of any diseased or spotty plants as you remove them from your garden. Include the variety of plants and where it was planted, and discard the debris far away from your garden or compost pile.
- Decide if you will plant a cover crop this fall and acquire the seeds for planting.
- Consider season-extending tools like hoop-houses, cold frames, and greenhouses. You can also stock up on row covers to protect crops from upcoming frosts. Be prepared for any early frosts.
- Look around your yard for anything that needs repair or change. Would you like to start a compost area? Does a fence need repair? Does your vegetable garden need more secure fencing? Would you like to build raised beds or build some climbing structures? Write down any materials that you might need for these projects.
- Check back to your gardening wish list in your garden journal for any items that may be on clearance racks at the end of the summer season. Now is a great time to pick them up at a discount.
- Consider what new perennials and shrubs you’d like to add to your landscape. Early fall is an excellent time for planting.
- Are your seed packets in a jumbled mess after this summer of vigorous planting? Consider ordering some seed organizing supplies and write this down as a late fall or winter task.
Fall Garden Prep & Maintenance
September gardening is big for prep and maintenance. Not sure what you should be doing in the garden this month? Here are some key tasks to get you started.
Late Summer Garden Weeding
Keep up with organic weed control during September gardening. You may be tempted to let them be and have future frosts kill them off. Avoid this methodology because you don’t want those weeds to go to seed and be even more of a problem next year.
- It gives the yard and garden a fresh look.
- Mulch enriches the soil over time as it breaks down.
- Mulch stomps out those fall weeds.
- Prevents soil erosion from heavy rains, winds, and storms.
- Retains moisture during bouts of drier weather.
- Insulates bulbs, perennial root systems for the upcoming cold weather.
End of Summer Watering
It can be much drier in September for those in Zones 6-8. Watering is vital to help new perennials and trees establish their root systems and for those already set plant root systems to stay adequately hydrated. Conversely, annual plantings are slowing down a bit in their growth, and cooler temperatures may mean they don’t need as much water as they did during the peak of summer.
When & What to Fertilize in September
- Stop fertilizing trees and shrubs during September gardening if you haven’t done so already. Cooler weather is approaching, and new growth established from fertilization can cause those limbs to be susceptible to damage.
- Fertilize vegetable gardens as needed. This includes gardens that include summer vegetable plants that are still producing, fall vegetable gardens, and gardens that have finished producing. Organic fertilizers help to build the soil and take time to break down to be available to plants for the next growing season.
- If you have a cool-season lawn variety, it’s time to fertilize your lawn. If you are unsure what kind of grass that you have, bring a small clump to your local extension office and ask for some guidance.
Fall Garden Pruning
- Stop pruning trees and shrubs. Cooler weather and frosts can cause new growth to be susceptible to damage.
- When September gardening, remove some foliage from pumpkin plants to allow fruits to ripen.
- Remove female flowers and immature fruits from squash, tomato, melons, pumpkins, and eggplants as they have little chance of maturing. Pinching them off will push the energy to fruits that are already established.
- Allow perennial plants to die back before cutting them back. Allow some seed heads to remain on plants for birds to feed on and for seed collection.
Other Garden Tasks on September Garden Checklist Zones 6-8
- It’s a great time to divide perennials like hostas, daylilies, rudbeckia, Shasta daisies, etc.
- Plant new hardy perennial plants in the cooler days of September. This gives plenty of time for roots to get established before winter sets in.
- Dig up tubers of gladiolus, dahlias, cannas, and caladiums and store them in a dry peat moss over the winter.
- Bring in any houseplants that you’ve had outside this summer. This includes potted citrus trees.
- Tidy up your garden landscape, picking up any dried foliage, dropped fruit, or dropped leaves.
- If you’ve been growing any tropical plants, start transitioning them indoors. They need to adjust to the change in lighting conditions gradually to prevent leaf drop.
- Start assembling your fall container gardens. Create an eye-catching pop of color and textural intrigue.
- Collect seeds from high-performing plants and store them in seed collection envelopes. Don’t forget to label them.
- Plant your spring bulbs. If you live in Zone 8, you may need to perform a cold treatment in the fridge for your bulbs before planting.
Late Summer Harvesting
Those in Zones 6-8 can continue harvesting all crops that continue to produce in the vegetable garden. It’s also apple picking time! Harvest your vegetable garden before the danger of frost or to make room for your fall plantings. Discard healthy spent leaves and plants into your compost pile.