Month by month · Oregon · Washington · Idaho
September in the garden
Harvest keeps going on the west side; frost arrives east of the Cascades and in the high desert. Time to put beds to rest.
What to plant in September
How much can go in across the five climate regions. Your region's row is highlighted once you pick a town.
| Region | Plant outside | Start indoors | September 1 – 30 |
|---|---|---|---|
| Coast | 8 plants, until Sep 17 | Nothing | |
| West-side valleys | 8 plants, until Sep 17 | Nothing | |
| East-side valleys | 8 plants, until Sep 17 | Nothing | |
| Inland Northwest | 12 plants | Nothing | |
| High desert | 6 plants, from Sep 20 | Nothing |
All 14 plants and their September dates, by region
| Plant | Coast | West-side valleys | East-side valleys | Inland Northwest | High desert |
|---|---|---|---|---|---|
| Plant Sep 3–17 | Plant Sep 3–17 | Plant Sep 3–17 | Plant Aug 31 – Sep 14 | — | |
| Plant Aug 20 – Sep 10 | Plant Aug 20 – Sep 10 | Plant Aug 20 – Sep 10 | Plant Aug 17 – Sep 7 | — | |
| Plant Aug 20 – Sep 3 | Plant Aug 20 – Sep 3 | Plant Aug 20 – Sep 3 | — | — | |
| Plant Aug 27 – Sep 10 | Plant Aug 27 – Sep 10 | Plant Aug 27 – Sep 10 | Plant Aug 24 – Sep 7 | — | |
| — | — | — | Plant Sep 25 – Oct 31 | Plant Sep 20 – Oct 20 | |
| Plant Aug 27 – Sep 17 | Plant Aug 27 – Sep 17 | Plant Aug 27 – Sep 17 | Plant Aug 24 – Sep 14 | — | |
| Plant Aug 20 – Sep 3 | Plant Aug 20 – Sep 3 | Plant Aug 20 – Sep 3 | — | — | |
| — | — | — | Plant Sep 25 – Oct 31 | Plant Sep 20 – Oct 20 | |
| — | — | — | Plant Sep 25 – Oct 31 | Plant Sep 20 – Oct 20 | |
| — | — | — | Plant Sep 25 – Oct 31 | Plant Sep 20 – Oct 20 | |
| — | — | — | Plant Sep 25 – Oct 31 | Plant Sep 20 – Oct 20 | |
| — | — | — | Plant Sep 25 – Oct 31 | Plant Sep 20 – Oct 20 | |
| Plant Aug 20 – Sep 10 | Plant Aug 20 – Sep 10 | Plant Aug 20 – Sep 10 | Plant Aug 17 – Sep 7 | — | |
| Plant Aug 13 – Sep 17 | Plant Aug 13 – Sep 17 | Plant Aug 13 – Sep 17 | Plant Aug 10 – Sep 14 | — |
Dates are for one typical town in each region: Astoria, Portland, Pendleton, Spokane and Bend and Redmond. Plant now shows your own town's dates.
September jobs
Plant and sow
- Plant a cover crop, such as crimson clover or cereal rye, in emptied beds.
- Sow spinach and mâche early in the month for overwintering. West-side valleys
- Plant garlic late in the month. High desert and Inland Northwest
- Plant spring bulbs like tulips and daffodils late in the month. East-side valleys
Start indoors
- Sow a tray of lettuce or herbs for a sunny windowsill.
Harvest
- Winter squash once the rind is hard and the stem is dry; cure it somewhere warm for two weeks.
- Tomatoes, peppers, beans and the last corn.
- Fall-bearing raspberries and late blueberries.
- Pick everything tender before the first frost. High desert and Inland Northwest
Garden care
- Pinch off new tomato flowers so the plant ripens fruit already on the vine.
- Cover tender crops on cold nights; watch the forecast. High desert and Inland Northwest
- Cut back watering as days cool, but don't let fall greens dry out.
- Write down what grew well and what didn't while you remember.
Pests and problems
- Pull and bag tomato and potato vines with late blight; don't compost them.
- Slugs come back with the fall rains. West-side valleys
Fruit, berries and flowers
- Plant and divide perennials; fall rain gets them established. West-side valleys
- Plant new strawberry plants or move runners into place.
- Lift and dry onion sets you'll replant.
Read next
Winter Cover Crops for Northwest Vegetable BedsWhy to sow cover crops in empty beds each fall, which ones grow well in Northwest gardens, and how to turn them under in spring.
When and How to Plant Garlic in Oregon, Washington and IdahoGarlic goes in during fall and comes out the next summer. Here's when to plant it where you live, which kind to buy, and how to harvest and cure it.
Fall and Winter Vegetable Gardening West of the CascadesHow to keep harvesting kale, carrots, garlic and greens through a mild Northwest winter, and when to plant for it.