The four dates that matter
| Date | When | What it means |
|---|---|---|
| Last spring frost (50%) | Apr 27 | Half of all years see a freeze after this date. It is an average, not a guarantee. |
| Last spring frost (10%) | May 10 | Only one year in ten freezes after this. Use it for anything you cannot afford to replant. |
| First fall frost (50%) | Oct 11 | Half of all years freeze before this date. Fall crops are counted back from here. |
| First fall frost (10%) | Sep 28 | An early-freeze year. If a crop must finish, aim to harvest before this. |
Spring & summer planting in Pasco
Dates are calculated from this location's own last-frost date, not from a generic zone chart. โBest moon daysโ are the days inside each window that fall in the crop's traditional phase โ the same rule the app uses.
| Crop | Start seed indoors | Plant outdoors | Best moon days | Days to harvest |
|---|---|---|---|---|
| Strawberry (crowns) transplant |
โ | Feb 26 โ Apr 6 | Mar 3, Apr 1 Full Moon |
perennial โ first real harvest next season |
| Garlic cloves/sets Better planted in fall โ see below |
โ | Mar 11 โ Apr 11 | Apr 2โ7 Waning Gibbous |
240โ300 |
| Asparagus (crowns) transplant |
โ | Mar 16 โ Apr 20 | Mar 25 First Quarter |
perennial โ first real harvest 2โ3 years |
| Chives either |
Mar 2 | Mar 16 โ Apr 20 | Mar 19โ24 Waxing Crescent |
75โ90 |
| Onion (from sets/transplants) cloves/sets |
โ | Mar 16 โ Apr 20 | Apr 2โ7 Waning Gibbous |
90โ120 |
| Peas (English/snap) direct sow |
โ | Mar 16 โ Apr 20 | Mar 25 First Quarter |
55โ75 |
| Spinach direct sow |
โ | Mar 16 โ Apr 20 | Mar 19โ24 Waxing Crescent |
35โ50 |
| Cabbage transplant |
Feb 23 | Mar 23 โ Apr 20 | Mar 23โ24, Apr 18โ20 Waxing Crescent |
65โ90 |
| Collards either |
Mar 16 | Mar 23 โ May 11 | Mar 23โ24, Apr 18โ21 Waxing Crescent |
55โ85 |
| Kale either |
Mar 16 | Mar 23 โ Apr 27 | Mar 23โ24, Apr 18โ21 Waxing Crescent |
50โ65 |
| Lettuce (leaf) either |
Mar 23 | Mar 23 โ May 18 | Mar 23โ24, Apr 18โ21 Waxing Crescent |
40โ55 |
| Potato cloves/sets |
โ | Mar 23 โ Apr 27 | Apr 1 Full Moon |
70โ120 |
| Radish direct sow |
โ | Mar 23 โ May 18 | Apr 2โ7 Waning Gibbous |
22โ35 |
| Turnip direct sow |
โ | Mar 23 โ May 4 | Apr 2โ7 Waning Gibbous |
40โ60 |
| Broccoli transplant |
Feb 23 | Mar 28 โ Apr 27 | Apr 18โ22 Waxing Crescent |
55โ80 |
| Brussels Sprouts transplant |
Feb 23 | Mar 28 โ Apr 27 | Apr 18โ22 Waxing Crescent |
90โ110 |
| Leek transplant |
Feb 16 | Mar 28 โ Apr 27 | Apr 2โ7 Waning Gibbous |
100โ120 |
| Lettuce (head) transplant |
Mar 9 | Mar 28 โ Apr 27 | Apr 18โ22 Waxing Crescent |
60โ85 |
| Parsley either |
Feb 23 | Mar 28 โ May 4 | Apr 18โ22 Waxing Crescent |
70โ90 |
| Parsnip direct sow |
โ | Mar 28 โ May 4 | Apr 1, May 1 Full Moon |
100โ150 |
| Shallot cloves/sets Better planted in fall โ see below |
โ | Mar 28 โ Apr 27 | Apr 2โ7 Waning Gibbous |
90โ120 |
| Beet direct sow |
โ | Mar 30 โ May 18 | Apr 1, May 1 Full Moon |
50โ65 |
| Kohlrabi either |
Mar 16 | Mar 30 โ May 4 | Apr 18โ22 Waxing Crescent |
45โ60 |
| Carrot direct sow |
โ | Apr 6 โ May 18 | May 1 Full Moon |
65โ85 |
| Cauliflower transplant |
Feb 23 | Apr 6 โ Apr 27 | Apr 18โ22 Waxing Crescent |
55โ80 |
| Cilantro direct sow |
โ | Apr 6 โ May 18 | Apr 18โ22, May 17 Waxing Crescent |
45โ70 |
| Swiss Chard direct sow |
โ | Apr 6 โ May 27 | Apr 18โ22, May 17 Waxing Crescent |
50โ60 |
| Dill direct sow |
โ | Apr 13 โ May 27 | Apr 18โ22, May 17 Waxing Crescent |
40โ60 |
| Cucumber either |
Apr 6 | Apr 27 โ May 27 | May 23 First Quarter |
50โ70 |
| Green Beans (bush) direct sow |
โ | Apr 27 โ Jun 11 | May 23 First Quarter |
50โ65 |
| Oregano transplant |
Mar 2 | Apr 27 โ May 18 | โ First Quarter |
cut as needed |
| Sage transplant |
Mar 2 | Apr 27 โ May 18 | โ First Quarter |
cut as needed |
| Sweet Corn direct sow |
โ | Apr 27 โ Jun 11 | May 23 First Quarter |
60โ100 |
| Thyme transplant |
Mar 2 | Apr 27 โ May 18 | โ First Quarter |
cut as needed |
| Zucchini / Summer Squash either |
Apr 6 | Apr 27 โ May 27 | May 23 First Quarter |
45โ60 |
| Basil either |
Mar 16 | May 4 โ May 27 | May 17โ22 Waxing Crescent |
30โ60 |
| Dry Beans direct sow |
โ | May 4 โ Jun 1 | May 23 First Quarter |
85โ100 |
| Pole Beans direct sow |
โ | May 4 โ Jun 6 | May 23 First Quarter |
60โ75 |
| Pumpkin direct sow |
Apr 6 | May 4 โ Jun 1 | May 23 First Quarter |
90โ120 |
| Rosemary transplant |
Apr 27 | May 4 โ May 27 | May 23 First Quarter |
cut as needed |
| Tomatillo transplant |
Mar 16 | May 4 โ May 27 | May 23 First Quarter |
60โ75 |
| Tomato transplant |
Mar 16 | May 4 โ May 27 | May 23 First Quarter |
60โ85 |
| Winter Squash direct sow |
Apr 6 | May 4 โ Jun 1 | May 23 First Quarter |
85โ110 |
| Cantaloupe / Muskmelon either |
Apr 6 | May 11 โ Jun 1 | May 23 First Quarter |
75โ90 |
| Eggplant transplant |
Mar 2 | May 11 โ Jun 1 | May 23 First Quarter |
60โ90 |
| Okra direct sow |
Mar 30 | May 11 โ Jun 6 | May 23 First Quarter |
50โ70 |
| Pepper transplant |
Mar 2 | May 11 โ Jun 1 | May 23 First Quarter |
60โ90 |
| Sweet Potato slips |
โ | May 11 โ Jun 6 | Jun 1โ6 Waning Gibbous |
90โ150 |
| Watermelon either |
Apr 6 | May 11 โ Jun 1 | May 23 First Quarter |
70โ90 |
Fall planting in Pasco
Fall dates count backward from the first frost, and they add time back for the โfall factorโ โ days are shortening and cooling, so a crop grows slower than the seed packet promises. Sowing late is the single most common way a fall garden fails.
| Crop | Sow or set out | Best moon days | Days to harvest | Hardiness |
|---|---|---|---|---|
| Brussels Sprouts | May 29 โ Jun 15 | Jun 15 | 90โ110 | hardy |
| Potato | Jun 3 โ Jul 5 | Jun 29 | 70โ120 | semi-hardy |
| Pole Beans | Jun 18 โ Jul 1 | Jun 21 | 60โ75 | tender |
| Parsley | Jun 21 โ Jul 5 | โ | 70โ90 | semi-hardy |
| Okra | Jun 23 โ Jul 23 | Jul 21 | 50โ70 | very tender |
| Cabbage | Jun 28 โ Jul 10 | โ | 65โ90 | hardy |
| Carrot | Jun 28 โ Jul 10 | Jun 29 | 65โ85 | semi-hardy |
| Collards | Jun 28 โ Jul 20 | Jul 15โ20 | 55โ85 | hardy |
| Cucumber | Jun 28 โ Jul 11 | โ | 50โ70 | tender |
| Broccoli | Jul 3 โ Jul 20 | Jul 15โ20 | 55โ80 | hardy |
| Cauliflower | Jul 3 โ Jul 20 | Jul 15โ20 | 55โ80 | semi-hardy |
| Green Beans (bush) | Jul 3 โ Jul 11 | โ | 50โ65 | tender |
| Lettuce (head) | Jul 3 โ Jul 15 | Jul 15 | 60โ85 | semi-hardy |
| Peas (English/snap) | Jul 3 โ Jul 20 | โ | 55โ75 | hardy |
| Beet | Jul 8 โ Jul 25 | โ | 50โ65 | semi-hardy |
| Kale | Jul 8 โ Jul 25 | Jul 15โ20 | 50โ65 | hardy |
| Swiss Chard | Jul 8 โ Jul 25 | Jul 15โ20 | 50โ60 | semi-hardy |
| Zucchini / Summer Squash | Jul 8 โ Jul 16 | โ | 45โ60 | tender |
| Basil | Jul 13 โ Jul 31 | Jul 15โ20 | 30โ60 | very tender |
| Kohlrabi | Jul 13 โ Jul 30 | Jul 15โ20 | 45โ60 | hardy |
| Cilantro | Jul 18 โ Jul 30 | Jul 18โ20 | 45โ70 | semi-hardy |
| Lettuce (leaf) | Jul 18 โ Aug 4 | Jul 18โ20 | 40โ55 | semi-hardy |
| Turnip | Jul 18 โ Aug 4 | Jul 30โAug 4 | 40โ60 | hardy |
| Spinach | Jul 23 โ Aug 9 | โ | 35โ50 | hardy |
| Dill | Jul 28 โ Aug 4 | โ | 40โ60 | semi-hardy |
| Radish | Jul 28 โ Aug 22 | Jul 30โAug 4 | 22โ35 | hardy |
| Garlic | Sep 11 โ Nov 1 | Sep 27โOct 2 | 240โ300 | hardy |
| Shallot | Sep 25 โ Oct 26 | Sep 27โOct 2 | 90โ120 | hardy |
Where these numbers come from
The frost dates on this page are observed station normals, not estimates: they come from Pasco Tri Cities Ap (GHCN USW00024163), one of 6,808 U.S. stations in NOAA's 1991โ2020 Climate Normals. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map. Crop timing is expressed as offsets from your frost dates, drawn from university Extension planting guides.
How precise is any of this?
Extension recommendations for the same crop routinely disagree by two to four weeks, and occasionally more, so these offsets should be presented as windows and starting points rather than deadlines. Three things drive the spread. (1) Regional risk tolerance: for warm-season crops, Colorado State and Utah State put tomatoes, peppers and melons out about 14 days after the last frost, while University of Missouri's calendar works out to roughly 25-35 days after the last frost and University of Maryland's window runs from the frost date itself out to 45 days past it. That is a real 6-week spread for the single most popular garden crop, and it exists because a short-season mountain state is optimizing against a short season while a humid continental state is optimizing against cold, wet spring soil. (2) Soil temperature versus calendar date: most Extension services now say the honest trigger is soil temperature at 4 inches, not the frost date, and the frost-relative number is a convenience translation. A cold, wet spring can push the real date two or three weeks past the calendar recommendation. (3) Days-to-maturity is variety-specific and is measured differently for direct-seeded versus transplanted crops - seed catalogs count from transplant date for tomatoes, peppers, eggplant and cole crops, but from sowing for roots and greens - so a 'days to maturity' range of 60-85 for tomato is genuinely 60-85 depending on which packet you bought. Additionally, the average last frost is a 50% probability, meaning half of all years have a frost after that date; Extension services commonly advise waiting 1-2 weeks past it for anything frost-tender, or being prepared to cover. Treat every number here as plus or minus about 10-14 days.
On the station itself: a weather station is one point. Cities hold their heat, valleys pool cold air, and a garden on a north slope can run two weeks behind one a mile away. Treat this page as your starting point and let your own garden correct it โ that is exactly what the journal in the app is for.
Nearby locations
Planting reminders for Pasco
A short note at each new and full moon telling you what is in its window right now for Pasco โ worked out from the frost dates on this page. Free, one click to stop.
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