When to Plant Broccoli in Kent, WA
Published: April 21, 2026
Broccoli Planting Dates for Kent, WA
| Start seeds indoors | March 26–April 2 |
| Last frost (average) | May 7 |
| Transplant outdoors | April 9–19 |
| Direct sow outdoors | April 9–19 |
| Minimum soil temperature | 40°F |
| Expect first harvest | June 8 – June 28 |
| Fall crop planting | July 23–August 2 |
| Fall crop harvest | September 21 |
| First fall frost (average) | October 1 |
Best Broccoli Varieties for Kent, WA
For Zone 4b Kent, the best-performing broccoli varieties are Arcadia, Belstar, and Diplomat — all short-season varieties chosen for cool-climate reliability. These varieties are typically stocked by local nurseries and are the safest bets for gardeners new to broccoli in Kent.
Growing Broccoli in Kent
Kent 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 broccoli benefit from Kent's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
Kent's cooler summers are close to ideal for broccoli. The same conditions that limit tomato and pepper yields benefit cool-season crops — slower bolting, sweeter flavor, and longer harvest windows. The fall broccoli crop in Kent is often more productive than the spring crop.
Kent's well-draining loam soils are among the best for broccoli growing — focus on annual organic matter additions (2 to 3 inches of compost) and consistent moisture during drier months. Water broccoli at 1.5 inches per week; loam holds moisture evenly without the drought-crack cycle of heavy clay or the rapid-drain losses of pure sand.
Broccoli Calendar for Kent
| Month | Task |
|---|---|
| March | Start seeds indoors under grow lights |
| May | Last frost — harden off seedlings outdoors |
| April | Transplant outdoors into warm soil |
| June | Expect first harvest window to open |
| July | Start fall crop — transplants or direct sow |
| October | First fall frost — harvest remaining, end of outdoor season |
Broccoli Tips for Kent Gardeners
- •For spring: start indoors 6 weeks before last frost and transplant outdoors 4 weeks before last frost.
- •For fall: start indoors in summer — count 10 weeks back from your first fall frost date.
- •Fall plantings in Kent often out-produce spring plantings — cooler temperatures slow bolting and concentrate flavor. Light frost can actually improve the taste of broccoli.
Common Broccoli Pests in Kent
- •Cabbage Worm — peaks July in Zone 4b (active June–August); green caterpillars on brassicas; apply Bt spray or use row covers.
- •Cabbage Looper — peaks July in Zone 4b (active June–August); loop-walking green caterpillars; Bt spray works well.
- •Aphids — peaks July in Zone 4b (active June–August); clusters on leaf undersides; blast with a strong water spray or apply neem oil.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Broccoli in Kent
In Kent's cold climate, Onion and Garlic are the most beneficial plants to grow alongside broccoli. Onion deters carrot fly, aphids, and several root-zone pests through sulfur compounds. Keep broccoli away from Tomato — it competes for nutrients or shares pest pressure. In short-season gardens, interplanting companions at transplant time maximizes each bed's productive weeks.
Frequently Asked Questions
When should I plant broccoli in Kent, WA?
In Kent (Zone 4b), start broccoli seeds indoors around March 26–April 2 and transplant outdoors around April 9–19. The city's average last frost of May 7 is the anchor date — count 6 weeks back for seed starting and 4 weeks back for transplanting.
What zone is Kent, WA for broccoli growing?
Kent is USDA Zone 4b. For broccoli, this means a frost-free growing season of roughly 21 weeks running from May 7 to October 1. Cool-season crops like broccoli thrive in this zone with both spring and fall planting windows available.
When is broccoli harvest season in Kent?
Expect the first broccoli harvest in Kent around June 8, with harvest continuing through June 28. This is based on 60–80 days from transplant or direct sow. A fall crop planted July 23–August 2 adds a second harvest around September 21.
How long does it take to grow broccoli in Kent, WA?
From transplant or direct sow to first harvest, broccoli takes 60–80 days in Kent's climate. Based on a typical planting date of April 9–19, expect your first harvest around June 8. Kent's cooler Zone 4b climate often lands at the slower end of this range — cooler nights slow fruit development.
What soil does broccoli need in Kent?
Kent's loam soil is near-ideal for broccoli. 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.