Metro areas

Gardening in Spokane-Spokane Valley, WA

This metro spans USDA zones 6a to 7a, so there is no single zone for Spokane-Spokane Valley, WA and anyone who gives you one is rounding. 69% of its ZIP codes are zone 6b; the rest are not.

USDA zones 6a–7a 3 zones across 55 ZIP codes
ZIP codes 55 55 have a NOAA station within range
Weather stations 11 NOAA 1991–2020 normals, across 4,241 sq mi

Which zone you are in depends where you are

Spokane-Spokane Valley, WA covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 69% in zone 6b and wrong for the other 31%. Here is the actual split.

Zone ZIP codes Share  
6b 38 69%
7a 13 24%
6a 4 7%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

Last spring freeze April 26 – June 6
First fall freeze September 4 – October 15

Those are the earliest and latest medians among the 11 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.

The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.

Your growing season

NOAA publishes a growing-season length for each station, and across the 11 stations serving Spokane-Spokane Valley, WA it runs 94–170 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 78–85 °F , below the 90 °F point where cool-season crops reliably bolt.

When to start seeds in Spokane-Spokane Valley, WA

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 11 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.

Crop Job When Offset
Green Onions Start indoors March 1 – April 11 8 weeks before
Peppers Start indoors March 1 – April 11 8 weeks before
Broccoli Start indoors March 15 – April 25 6 weeks before
Cabbage Start indoors March 15 – April 25 6 weeks before
Collards Start indoors March 15 – April 25 6 weeks before
Kale Start indoors March 15 – April 25 6 weeks before
Leaf Lettuce Start indoors March 15 – April 25 6 weeks before
Peas Direct sow March 15 – April 25 6 weeks before
Spinach Direct sow March 15 – April 25 6 weeks before
Sweet Potato Start indoors March 15 – April 25 6 weeks before
Tomatoes Start indoors March 15 – April 25 6 weeks before
Bok Choy Start indoors March 22 – May 2 5 weeks before
Kohlrabi Start indoors March 22 – May 2 5 weeks before
Swiss Chard Start indoors March 22 – May 2 5 weeks before
Arugula Direct sow March 29 – May 9 4 weeks before
Baby Salad Greens Direct sow March 29 – May 9 4 weeks before
Beets Direct sow March 29 – May 9 4 weeks before
Green Onions Direct sow March 29 – May 9 4 weeks before
Mustard Greens Direct sow March 29 – May 9 4 weeks before
Okra Start indoors March 29 – May 9 4 weeks before
Radishes Direct sow March 29 – May 9 4 weeks before
Turnips Direct sow March 29 – May 9 4 weeks before
Cabbage Set out April 5 – May 16 3 weeks before
Carrots Direct sow April 5 – May 16 3 weeks before
Collards Direct sow April 5 – May 16 3 weeks before
Collards Set out April 5 – May 16 3 weeks before
Cucumbers Start indoors April 5 – May 16 3 weeks before
Green Onions Set out April 5 – May 16 3 weeks before
Kale Direct sow April 5 – May 16 3 weeks before
Kale Set out April 5 – May 16 3 weeks before
Kohlrabi Direct sow April 5 – May 16 3 weeks before
Kohlrabi Set out April 5 – May 16 3 weeks before
Leaf Lettuce Direct sow April 5 – May 16 3 weeks before
Pumpkins Start indoors April 5 – May 16 3 weeks before
Summer Squash Start indoors April 5 – May 16 3 weeks before
Winter Squash Start indoors April 5 – May 16 3 weeks before
Zucchini Start indoors April 5 – May 16 3 weeks before
Bok Choy Direct sow April 12 – May 23 2 weeks before
Bok Choy Set out April 12 – May 23 2 weeks before
Broccoli Set out April 12 – May 23 2 weeks before
Cilantro Direct sow April 12 – May 23 2 weeks before
Leaf Lettuce Set out April 12 – May 23 2 weeks before
Swiss Chard Direct sow April 12 – May 23 2 weeks before
Swiss Chard Set out April 12 – May 23 2 weeks before
Dill Direct sow April 19 – May 30 1 week before
Bush Beans Direct sow May 3 – June 13 1 week after
Cucumbers Set out May 3 – June 13 1 week after
Pumpkins Direct sow May 3 – June 13 1 week after
Pumpkins Set out May 3 – June 13 1 week after
Summer Squash Direct sow May 3 – June 13 1 week after
Summer Squash Set out May 3 – June 13 1 week after
Sweet Corn Direct sow May 3 – June 13 1 week after
Tomatoes Set out May 3 – June 13 1 week after
Winter Squash Direct sow May 3 – June 13 1 week after
Winter Squash Set out May 3 – June 13 1 week after
Zucchini Direct sow May 3 – June 13 1 week after
Zucchini Set out May 3 – June 13 1 week after
Cucumbers Direct sow May 10 – June 20 2 weeks after
Okra Direct sow May 10 – June 20 2 weeks after
Okra Set out May 10 – June 20 2 weeks after
Peppers Set out May 10 – June 20 2 weeks after
Southern Peas Direct sow May 10 – June 20 2 weeks after
Sweet Potato Set out May 10 – June 20 2 weeks after

The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.

What survives the winter changes across Spokane-Spokane Valley, WA

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 58 come through the winter in zone 7a and only 51 in zone 6a. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
6a 4 51 of 74 0
6b 38 51 of 74 0
7a 13 58 of 74 1

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

The 11 stations behind these numbers

Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.

Station NOAA ID Last spring freeze First fall freeze Season
Chewelah, WA USC00451395 May 16 September 15 120 days
Colville, WA USC00451630 May 2 October 2 153 days
Davenport, WA USC00452007 June 6 September 11 94 days
Deer Park AP, WA USW00094119 May 22 September 14 112 days
Northport, WA USC00455946 May 8 October 1 143 days
Plummer 3 Wsw, ID USC00107188 May 11 October 5 143 days
Rosalia, WA USC00457180 May 7 September 28 144 days
Spokane 17 Ssw, WA USW00004136 May 30 September 4 94 days
Spokane Felts FLD, WA USW00094176 April 26 October 15 170 days
Spokane INTL AP, WA USW00024157 April 26 October 12 168 days
Spokane Wfo, WA USC00457941 May 10 September 26 137 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Where these numbers come from

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

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