September in the Pacific Northwest is a very short period. The garden wants to continue summer, but it will also enter autumn. The gardener’s two very different chores may conflict, but don’t let it stop you from maintaining your garden. The weather is still quite warm and sunny, leading to the familiar “second summer” here in the Pacific Northwest, but autumn rains will also begin to help with more traditional fall chores. By taking care of summer and autumn housework in September, you can enjoy your garden even more.
Collect and sow seeds. go through Collect seeds From your early summer annuals, biennials and perennials, you can greatly increase your garden collection, especially the plants you have successfully grown. Collecting seeds is also a fun way to interact with your garden in a completely different way. Spanish poppy (poppy, Area 6-9), Tall verbena (Verbena, Districts 7-11), and “Sunset Boulevard” Evening Primrose (Evening primrose “Sunset Boulevard”, areas 4–10b) are some of the easiest and most productive self-planters that can be collected in your garden, redistributed or given to gardening friends. I like to plant seeds immediately after collection or at least later in the fall to ensure that the seeds have a period of vernalization (cold treatment). Most seeds need some cooling period or even winter cold to germinate and grow in early spring.
Take care of your lawn. Speaking of reseeding, September is a good month to supervise the lawn and correct any exposed spots or areas that require additional coverage. The beginning of the autumn rain also reduces the amount of watering you need to do. All lawns need to be maintained every six months to keep them in their best condition. Take care of this task now and your lawn will look great next year. I like to spread a fine layer of compost on my lawn, and then replant it with some dolomite lime to offset the typical acidic soils in the Northwest (always follow the recommended application rate on the package), thereby creating a new lawn Seeds provide extra power.For more tips on lawn care in the fall, read on here.
Replace failed plants. September is a good time to reassess the garden. Plants that fail to perform in the placement location may require a new location or be completely removed from your garden. Especially in smaller urban gardens, space is very precious. If a plant does not work, find one that works. There is no harm in editing your garden when needed. The removed plants can be used in other more suitable areas of your garden, given to friends, or composted in the worst case.
Repair the hydrophobic potting soil of the container. If you find that your small pots dry out quickly or your plants seem to be struggling, try soaking them in a bucket of water. The container soil will completely dry out in the late summer when it is hot, and then the soil will become hydrophobic. One sign of this situation is that when you water the container plant, the water just flows from the bottom of the container, but the soil does not get wet. When this happens, take a garden bathtub or a 5-gallon bucket, fill it with water, and completely submerge the container for 20 to 30 minutes. Usually, you will notice bubbles in very dry soil. Once rehydrated, these containers should look better, but when you hand over water, they should also be ready to absorb additional moisture. If your plants can no longer hydrate or have passed their heyday, it may be time to look for cool annuals and other plants that can provide interest in the fall and beyond. Just remember the soaking technique until the autumn rain begins. This is equally effective for new plants that have not been planted due to lack of rain.
Continue to fall. Finally, in order for your garden to blossom and bear fruit in September and beyond, remember to plant headless roses and dahlias (Dahlia Genus and cvs., zones 7-11), sage (Salvia Genus and cvs., Zones 5-11) and other late-season perennials to encourage re-flowering or use as late-season bouquets at home.
Regardless of the weather, September is a good time to work in the garden. The sunny days in the late season, coupled with the cool and sometimes rainy nights, are a good time to recharge. Be sure to enjoy all the hard work you put in the garden this year. This is also a good time to reflect and make necessary changes, but go out and enjoy it anyway.
—Jason Jorgensen is a landscape architect in Seattle.