MONTHLY GARDENING TIPS
Here’s what to do, what’s in bloom, and lots of tips and tricks for each month of the year. Check back each month to find new, seasonal tips for ornamental gardening, lawn care, edible gardening, and indoor plant care in the Pacific Northwest!
September Tips for PNW Gardeners
In the Garden
Mulch now to help minimize weeds and protect plants as the weather gets colder.
Want to add some blooms to the late-summer garden? Check out our Favorite Fall Perennials & Annuals, as well as our Favorite Fall Trees & Shrubs!
September is a great month to freshen up your containers with new plants. See our ideas in Refreshing Your Containers for Fall.
Now through October, you can transplant and divide spring-flowering perennials and bulbs.
Your plants need water to thrive, especially those that are newly planted, and September can still be a dry month in the PNW. Take a look at our Best Watering Practices.
Fall is the time to mulch your garden beds to add nutrients and help protect plant roots this winter.
Edible Gardening
Keep harvesting! Zucchinis are best harvested small for sweet, tender flesh. Tomatoes should be left to ripen as long as possible on the plant before picking.
You can plant these vegetables now for fall and winter harvests: arugula, lettuce, kale, Asian greens, and radishes. Learn more about Planting a Fall Vegetable Garden.
Battling Powdery Mildew? It's very common here in the PNW, but there are things you can do to help control it.
As fall approaches, some vegetable plants will slow their growth and will begin to die off. Promptly remove any dead plants from the garden and compost them. Note: If a plant is diseased or infested with insects, do not put it in your home compost pile.
If you have empty vegetable beds, sow a cover crop like vetch, crimson clover, or rye to improve soil structure and add nutrients over the winter! Learn more about Cover Crops.
Lawn Care
In September, you can begin fertilizing your lawn. Be sure to water regularly after fertilizing, especially in drier weather.
This is a great month to tackle Lawn Renovation by aerating, filling in low spots, and sowing grass seed.
Don't mow still-dormant sections of lawn. You can mow green lawn areas.
Remember that the height of the grass generally equals the depth of the roots, so keeping grass a little longer helps build a strong support system. Set your mower to medium height to avoid cutting off more than 30% at a time.
Indoor plants
You can still fertilize your actively growing houseplants in September, but begin tapering down on frequency as we move into fall. See our September Checklist for Fall & Winter Houseplant Care.
As the weather cools, be sure to bring inside any houseplants that have "summered" out of doors. Check carefully for insects that might be tagging along and consider keeping these plants separated from others until they are bug-free. Not sure what pest you’re dealing with? See our blog post, What’s Attacking My Houseplant?
Don’t have a green thumb? We can help! Try these 5 Easy Houseplants.