Washington · zones 6b–9a
When to plant carrots in Washington.
Sow between Mar 7 to Apr 9 in a typical year, keyed to Washington's median last frost around Apr 14. A second, fall sowing fits Jul 23 to Aug 18. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Carrots dates for a typical Washington season.
Direct sow
Mar 7 to Apr 9
Keyed to the ~Apr 14 last frost. Sow 0.25" deep, 2" apart.
Fall round
Jul 23 to Aug 18
Counted back from the ~Oct 18 first frost.
Harvest
~68 days later
~0.2 lb per plant over ~2 weeks.
Washington spans more than one climate: Zone 8 is the most common zone, but the state runs 6b to 9a. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
Washington growing notes
Washington carrots split along the Cascades.
Two soils, two states
Washington's carrot story runs through the Columbia Basin, the irrigated desert east of the Cascades around Othello and Moses Lake, which grows a meaningful share of the country's processing carrots on deep sandy loam that a carrot root can push through without resistance. West of the mountains, Puget Sound gardens usually work with heavier, wetter clay-influenced soils. The Sound lowlands themselves see something like 35 to 39 inches of rain most years, well short of the 100-plus inches that lands on the Olympic Peninsula across the region's own rain shadow, but still enough to build soil that resists a straight taproot instead of welcoming one.
The fix on the wet side is mechanical: work 3 inches of compost into the top 10 inches of bed, or build a raised bed entirely, since carrots grown in unmodified west-side clay commonly fork or grow stubby no matter how good the seed is. East-side gardeners with the Columbia Basin's naturally loose soil can skip most of that labor and focus fertility instead. Rock and heavy clumps left in a west-side bed cause the same forking a dense soil does, so rake the top foot clear of anything bigger than a marble before the row goes in.
Six sowings and a cool finish
Washington's growing season supports roughly 6 carrot sowings from spring through late summer, spaced every few weeks, which spreads harvest across most of the year rather than dumping one crop all at once. The last sowing, timed to mature as fall cools down, is worth planning for specifically: carrots that finish in cooling weather convert stored starch to sugar, and a carrot pulled after a cold snap will taste noticeably sweeter than one pulled from the same row in August heat.
West-side gardeners get a bonus most of the state does not: mild winters mean a fall carrot crop can often stay in the ground under a foot of straw mulch and be dug as needed into December, rather than needing to be lifted and stored all at once the way a harder winter would force.
Rust fly pressure differs by side of the mountains
Carrot rust fly is worse in the cool, humid conditions common west of the Cascades, where the fly's preferred weather persists most of the growing season; row cover laid immediately after sowing and left on until harvest is the most reliable defense, since the fly lays eggs at the soil line and cover denies it that access entirely.
East-side gardens in the drier Columbia Basin see less rust fly pressure but more aphids feeding on foliage during the hot, irrigated summer; check leaf undersides every couple of weeks and hit visible colonies with a strong water spray before they spread to the whole row. Either side of the state, thin seedlings to 2 inches apart once tops reach 2 inches tall, or expect twisted, undersized roots at harvest. Pull thinned seedlings out at a slight angle instead of straight up, since a hard vertical pull disturbs the roots of the carrots left behind more than gardeners expect.
In Washington: watch for
The pests that find carrots here.
A middle-length season, about 187 frost-free days, means carrot overlaps carrot rust fly for a stretch each summer. Check plants every week or two and treat early.
Rusty tunnels in the roots and stunted tops.
Organic fix: Cover the row; rotate away from last year's carrots.
Big green-and-black striped caterpillars on the foliage.
Organic fix: Handpick (or leave for swallowtails); Bt if heavy.
Brown spots ringed in yellow on the oldest leaves first, darkening until the tops look scorched.
Organic fix: Water at the base rather than overhead, turn under old carrot tops, and leave 2 years between carrot crops.
Your season math: Washington gives carrots about 187 frost-free days, and it needs roughly 68 days to a first harvest. That fits about 6 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting carrots in Washington: questions
When should I plant carrots in Washington?+
In a typical Washington year, sow carrots between Mar 7 to Apr 9, keyed to the state's median last frost around Apr 14. There's also a fall window: Jul 23 to Aug 18. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Washington?+
Washington spans zones 6b–9a, mostly zone 8. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many carrots plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.