September is a pivotal month in the gardens for me. In zones 7 and 8 in the Pacific Northwest, the heat starts to settle down by the end of August. We still get warm days, but the heat dissipates as the sun sets, leading to cooler nights. The soil is still warm though, which helps the crops finish up.
The milder days are some of my favorite ones, to be in the garden working, cleaning up for the year, but also putting in next years ideas. This is the perfect month for garden tasks, where you can get a lot of work done, and sweat less. And it isn’t dark at 5 pm!
- Clean your beds of dead or dying back plants.
- As bean and pea plants die back, cut the plants to the ground, leave the roots in, to help with nitrogen. You can blend this in in spring.
- At the start of the month, trim tomato plants back of any blooms, so that the energy goes to the tomatoes to finish ripening.
- Place a clean board or brick under pumpkins, to keep them off the soil, as they finish ripening.
- Cut back leaves over pumpkins and winter squash, to let in light.
- Plant cold friendly annuals for a pop of color in fall. Nurseries will have plenty right now, and they often bloom into November and December. They will often come back in Spring, unless we have a very harsh winter.
- Start prepping your garlic and fall onion beds. Amend the soil as desired and mark the spots. Don’t plant though till the end of the month at the earliest (October is even fine for planting), however it is easiest to move the soil in September as it is still warm.
- Buy garlic and onion to plant, if needed.
- Trim back herbs, and save to dry. Do this in the early morning and stash in new brown paper bags to dry. Mark each bag with what is inside. Once dry, store in mason jars out of direct sunlight.
- Do a fall fertilizing of blueberry bushes and trees, water well after.
- If building new beds for next year (the cooler weather makes it a nice time!) lay down a lot of cardboard to help smother weeds.
- Clean out your garden shed (If you have one).
- Sharpen tools and clean them for winter storage.
- Clean your greenhouse (if you have one), removing dead plants and giving it a good sweeping out.
- Wash and dry empty pots, stack for fall storage, out-of-the-way, so fall storms don’t blow them away.
- Water and turn your compost piles/bins.
- Should you find any deals on berry or fruit trees, get them in the ground this month.
- Avoid ANY desire to prune trees. Wait till it is winter! Trees and bushes are starting to go into being dormant, and need their rest.