When to plant turnips in Friday Harbor and the San Juans, WA

Plant turnips from seed, directly in the garden in Friday Harbor and the San Juans, Mar 1 – Apr 12. For a fall harvest, plant again Aug 13–27.

Easy Plant seeds in the ground

Difficulty: Easy
Sun: Full sun
Spacing: Thin to 4 inches apart
Planting depth: ½ inch deep
Frost: Handles light frost
First harvest: About 50 days after planting

Why these dates

Friday Harbor and the San Juans's typical last spring frost is March 26. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the west-side valleys, though, the soil usually isn't ready to work until about March 1.

West-side valleys. The Willamette Valley, Puget Sound and southern Oregon valleys. Long frost-free seasons, but soil stays cold and wet into May, so warm crops wait for warm soil, not just the last frost.

How to grow turnips in Friday Harbor and the San Juans

Prepare the bed: loosen the soil and mix in an inch or two of compost.
Plant seeds Mar 1 – Apr 12, ½ inch deep, Thin to 4 inches apart.
Keep the soil evenly moist until sprouts appear, which can take one to three weeks in cool soil.
Plant again Aug 13–27 for a fall harvest.
Harvest: Pull at 2 to 3 inches across for tender roots. The greens are good to eat too.

Key numbers

50–85°FSoil to sprout
6.0–7.5Soil pH
About 35–55Days to harvest
Root maggotsBiggest risk

Growing notes

What makes the difference in Northwest gardens, in plain language.

Soil and sowing

Turnips grow best in loose, well-drained soil with a pH of about 6.0 to 7.5. Mix in some compost, but avoid heavy nitrogen, which grows leaves instead of roots. Sow seeds directly, keep the soil moist until they sprout, and thin early so each plant has room. Crowded turnips stay small and lopsided. Steady watering keeps roots sweet and smooth; dry soil makes them hot and woody.

Spring vs fall, and why fall is sweeter

Turnips are a cool-season crop. In spring, warm weather and long days can make roots tough and plants bolt, so sow as early as the soil allows and pick young. Fall crops, sown in mid to late summer, mature as the weather cools, and a light frost turns some of their starches to sugar. West of the Cascades, fall turnips often hold in the ground into early winter. East of the Cascades, harvest before the soil freezes hard. Hakurei is a quick, mild salad turnip, while Purple Top White Globe is the classic for cooking and storage.

Root maggots, harvest and storage

Cabbage root maggots tunnel into turnips in cool, wet soil, leaving brown trails. Row cover laid on at sowing keeps the egg-laying flies away, and rotating where you plant cabbage-family crops helps too. Pull roots at 2 to 3 inches across for the most tender texture. Twist off the greens, which are good cooked, and store roots in a bag in the fridge for several weeks. Larger fall turnips can keep for months in a cold, damp root cellar.

Common questions

When is the last frost in Friday Harbor and the San Juans, WA?

Typically March 26. In 9 years out of 10, frost is over by April 21. These are 1991–2020 NOAA climate normals for Friday Harbor Airport.

Is it too late to plant turnips in Friday Harbor and the San Juans?

The spring planting window runs through April 12. If you miss it, plant again for fall from August 13 to August 27.

How long until I can harvest turnips?

About 50 days after planting. Pull at 2 to 3 inches across for tender roots. The greens are good to eat too.

Why are my turnips woody or bitter?

They were probably left in the ground too long, grew in hot weather, or dried out. Pick turnips small, about 2 to 3 inches across, and keep the soil moist. Fall crops are usually the sweetest.

Can you eat turnip greens?

Yes, turnip greens are tasty cooked like spinach or collards. Young greens are the most tender. Take a few leaves from each plant if you still want good roots.

When should I plant turnips for fall?

Sow in mid to late summer so roots mature in the cool fall weather. Keep the seedbed moist during the heat of August. Check your local calendar for exact dates.

Also plant in Friday Harbor and the San Juans around the same time

Planting dates for turnips in nearby areas

Bellingham, WA Mar 1 – Apr 12
Mount Vernon and Burlington, WA Mar 1 – Apr 12
Anacortes, WA Mar 1 – Apr 12
Oak Harbor and Whidbey Island, WA Mar 1 – Apr 12
Portland, OR Mar 1 – Apr 12
Gresham, OR Mar 1 – Apr 12

Full planting calendar for Friday Harbor and the San Juans · Turnips in every city