When to Plant Turnips in Beaverton, OR
Published: April 24, 2026
Turnip Planting Dates for Beaverton, OR
| Start seeds indoors | Year-round |
| Last frost (average) | May 7 |
| Direct sow outdoors | April 16–26 |
| Minimum soil temperature | 40°F |
| Expect first harvest | May 21 – June 15 |
| Fall crop planting | August 6–16 |
| Fall crop harvest | September 10 |
| First fall frost (average) | October 1 |
⚠ Direct sow turnips 2–4 weeks before last frost for spring crop. Best planted in late summer (6–8 weeks before first fall frost) for fall harvest — frost sweetens the roots. Fast-growing: some varieties ready in just 35 days.
Best Turnip Varieties for Beaverton, OR
Consult a Beaverton-area nursery or your state extension office for turnip varieties proven in Zone 4b.
Growing Turnips in Beaverton
Beaverton sits in Zone 4b, with an average last frost of May 7 and first fall frost around October 1 — giving a 147-day frost-free growing season. Cool-season crops like turnip benefit from Beaverton's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
Beaverton's cooler summers are close to ideal for turnip. The same conditions that limit tomato and pepper yields benefit cool-season crops — slower bolting, sweeter flavor, and longer harvest windows. The fall turnip crop in Beaverton is often more productive than the spring crop.
Beaverton's well-draining loam soils are among the best for turnip growing — focus on annual organic matter additions (2 to 3 inches of compost) and consistent moisture during drier months. Water turnip at 1 inches per week; loam holds moisture evenly without the drought-crack cycle of heavy clay or the rapid-drain losses of pure sand.
Turnip Calendar for Beaverton
| Month | Task |
|---|---|
| Year | Start seeds indoors under grow lights |
| May | Last frost — soil warming, prepare bed |
| April | Direct sow seeds into warm soil |
| May | Expect first harvest window to open |
| August | Start fall crop — transplants or direct sow |
| October | First fall frost — harvest remaining, end of outdoor season |
Turnip Tips for Beaverton Gardeners
- •Thin seedlings to 4-inch spacing when plants are 3 inches tall — crowded turnips produce small woody roots.
- •Both roots AND greens are edible — harvest baby turnip greens 4 weeks after sowing, roots 5–9 weeks.
- •Fall plantings in Beaverton often out-produce spring plantings — cooler temperatures slow bolting and concentrate flavor. Light frost can actually improve the taste of turnip.
Common Turnip Pests in Beaverton
- •Flea Beetle — peaks July in Zone 4b (active June–August); tiny black beetles that riddle leaves with holes; row covers protect seedlings.
- •Aphid — peaks July in Zone 4b (active June–August); monitor closely during peak season and treat early.
- •Cabbage Root Maggot — peaks July in Zone 4b (active June–August); monitor closely during peak season and treat early.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Turnips in Beaverton
In Beaverton's cold climate, Pea and Mint are the most beneficial plants to grow alongside turnip. Pea improves nearby plant health and pest resistance. Keep turnip away from Potato — it competes for nutrients and shares blight diseases. In short-season gardens, interplanting companions at transplant time maximizes each bed's productive weeks.
Frequently Asked Questions
When should I plant turnip in Beaverton, OR?
In Beaverton (Zone 4b), direct sow turnip around April 16–26. Soil must be at 40°F or warmer at 2-inch depth before sowing — cold soil rots the seeds.
What zone is Beaverton, OR for turnip growing?
Beaverton is USDA Zone 4b. For turnip, this means a frost-free growing season of roughly 21 weeks running from May 7 to October 1. Cool-season crops like turnip thrive in this zone with both spring and fall planting windows available.
When is turnip harvest season in Beaverton?
Expect the first turnip harvest in Beaverton around May 21, with harvest continuing through June 15. This is based on 35–60 days from transplant or direct sow. A fall crop planted August 6–16 adds a second harvest around September 10.
How long does it take to grow turnip in Beaverton, OR?
From transplant or direct sow to first harvest, turnip takes 35–60 days in Beaverton's climate. Based on a typical planting date of April 16–26, expect your first harvest around May 21. Beaverton's cooler Zone 4b climate often lands at the slower end of this range — cooler nights slow fruit development.
What soil does turnip need in Beaverton?
Beaverton's loam soil is near-ideal for turnip. Work in 2–3 inches of compost before planting to boost organic matter and nutrient content. Minimal amendment is needed beyond that — loam holds moisture evenly without the drought-crack cycle of clay or the nutrient-loss issues of sandy soil.