What to plant in October in the Pacific Northwest

Worked out for 11 cities from their own weather and frost dates, by zone.

What to sow and plant in October in the Pacific Northwest, by zone: frost possible, highs of 61–72 °F (Boise, Eugene and 2 more): garlic, broad bean, peas, onion, spinach and 15 more; frost-free, highs of 61–72 °F (Portland and Salem): garlic, broad bean, peas, onion, spinach and 16 more; frost-free, highs of 50–61 °F (Seattle, Olympia and 1 more): garlic, broad bean, peas, onion, spinach and 16 more; frost possible, highs of 50–61 °F (Spokane and Idaho Falls): garlic, peas, spinach, lettuce, radish and 3 more.

In the Pacific Northwest, October is fall.

Frost possible, highs of 61–72 °F: Boise, Eugene, Medford and Yakima

In October, on average, these cities have highs of 64 to 66 °F and lows of 41 to 44 °F, 1.0 to 5.2 in of rain on 5 to 12 days; the day lasts 10 h 58 min to 11 h 07 min (on the 15th).

October falls in the frost season: frost-tender crops wait. Average first frost: Boise (October 27), Eugene (October 29), Medford (October 20) and Yakima (October 24).

How	What	Where
plant cloves	Garlic	all
sow direct	Broad bean, cabbage, broccoli	Eugene and Medford
sow direct	Peas, spinach, lettuce, radish, arugula, kohlrabi	all
plant sets	Onion	Eugene and Medford
sow direct	Swiss Chard, beet, parsley, cilantro, chamomile, daikon, dill, mustard greens	Boise, Eugene and Medford
sow direct	Turnip	Eugene
plant bulbs	Crocus, daffodil, hyacinth, tulip	all

Compared with September: new — radish, daikon and turnip; no longer sown — chickpea and shallot.

Not starting in October: tomato (no month outdoors by these rules), bell pepper (no month outdoors by these rules), zucchini (April, started indoors) and green beans (May, sown direct) — dates for Boise.

Ready to harvest in October in Boise, if sown in the right month: zucchini (August), green beans (August), basil (August), bok choy (August) and borage (August).

Frost-free, highs of 61–72 °F: Portland and Salem

In October, on average, these cities have highs of 62 to 65 °F and lows of 46 °F, 4.3 to 4.8 in of rain on 11 to 12 days; the day lasts 11 h 00 min to 11 h 02 min (on the 15th).

No frost in October in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
plant cloves	Garlic	all
sow direct	Broad bean, peas, spinach, lettuce, radish, cabbage, broccoli, Swiss chard, beet, parsley, cilantro, arugula, chamomile, daikon, dill, kohlrabi, mustard greens	all
plant sets	Onion	all
sow direct	Turnip	Portland
plant bulbs	Crocus, daffodil, hyacinth, tulip	all

Compared with September: new — garlic, radish, daikon, turnip, crocus, daffodil, hyacinth and tulip; no longer sown — chickpea and shallot.

Not starting in October: tomato (March, started indoors), bell pepper (March, started indoors), zucchini (April, started indoors) and green beans (June, sown direct) — dates for Portland.

Ready to harvest in October in Portland, if sown in the right month: zucchini (August), green beans (August), watermelon (July), sweet corn (July), basil (August), arugula (September), bok choy (August) and borage (August).

Frost-free, highs of 50–61 °F: Seattle, Olympia and Tacoma

In October, on average, these cities have highs of 59 to 60 °F and lows of 46 to 47 °F, 5.1 to 5.8 in of rain on 14 to 16 days; the day lasts 10 h 56 min to 10 h 57 min (on the 15th).

No frost in October in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
plant cloves	Garlic	Seattle and Olympia
sow direct	Broad bean, peas, spinach, lettuce, radish, cabbage, broccoli, Swiss chard, beet, parsley, cilantro, arugula, chamomile, daikon, dill, kohlrabi, mustard greens, turnip	all
plant sets	Onion	all
plant bulbs	Crocus, daffodil, hyacinth, tulip	Seattle and Olympia

Compared with September: new — garlic, radish, daikon, turnip, crocus, daffodil, hyacinth and tulip; no longer sown — carrot, chickpea, kale, parsnip and shallot.

Not starting in October: tomato (March, started indoors), bell pepper (March, started indoors), zucchini (April, started indoors) and green beans (June, sown direct) — dates for Olympia.

Ready to harvest in October in Olympia, if sown in the right month: zucchini (August), green beans (August), watermelon (July), sweet corn (July), basil (August), arugula (September), bok choy (August) and borage (August).

Frost possible, highs of 50–61 °F: Spokane and Idaho Falls

In October, on average, these cities have highs of 60 °F and lows of 36 to 39 °F, 1.4 to 2.2 in of rain on 7 to 9 days; the day lasts 10 h 55 min to 11 h 05 min (on the 15th).

October falls in the frost season: frost-tender crops wait. Average first frost: Spokane (October 15) and Idaho Falls (October 14).

How	What	Where
plant cloves	Garlic	all
sow direct	Peas, spinach, lettuce, radish, arugula, turnip	all
plant bulbs	Crocus, daffodil, hyacinth, tulip	all

Compared with September: new — radish and turnip; no longer sown — broad bean, onion, cabbage, beet, parsley, cilantro, chamomile, dill and 2 more.

Not starting in October: tomato (March, started indoors), bell pepper (March, started indoors), zucchini (April, started indoors) and green beans (June, sown direct) — dates for Spokane.

Ready to harvest in October in Spokane, if sown in the right month: zucchini (August), green beans (August), watermelon (July), pumpkin (June), sweet corn (July), basil (August), arugula (September) and bok choy (August).

How we work it out

For each city we use its average weather in October and the months after (highs, lows and rain for 2016–2025, ERA5 reanalysis via Open-Meteo) and its average frost dates. A crop starts in October if the month's mean temperature reaches the minimum soil temperature for germination on its card (we use the mean air temperature as a stand-in for the soil's) and if, over its first months (up to three), the average highs stay within its group's range, with no frost for crops that cannot take it. Crops started indoors count from the month they are planted out.

Temperature groups from Colorado State University Extension: cool-season crops prefer 60–80 °F and lose quality in heat; hardy ones grow in days as cool as 40 °F, semi-hardy ones from 40–50 °F (we use 50 °F); warm-season crops need days above 55 °F, and the most tender (tomato, pepper, eggplant, melon, watermelon, squash) above 60 °F, up to 95 °F. Crops the guide does not name go into the stricter group by their frost hardiness. Fava (broad) beans, which the guide does not name, count as hardy: hardy varieties are sown in fall and overwinter (RHS). Garlic and bulbs: a month before the first frost, and later only while the ground is not frozen (as on each city's page).

This is a general rule from averages: your garden can be a week or two earlier or later, and a greenhouse or a cold frame brings the season forward. Greenly works out the dates for your location.