When to Plant Cabbage in Boise, ID
Published: April 24, 2026
Cabbage Planting Dates for Boise, ID
| Start seeds indoors | February 25–March 4 |
| Last frost (average) | April 15 |
| Transplant outdoors | March 25–April 4 |
| Minimum soil temperature | 45°F |
| Expect first harvest | May 24 – July 3 |
| Fall crop planting | July 23–August 2 |
| Fall crop harvest | September 21 |
| First fall frost (average) | October 15 |
⚠ Start cabbage indoors 6–8 weeks before last frost. Transplant 2–4 weeks before last frost. Very frost tolerant — withstands temperatures as low as 20°F. Also plant in late summer for fall harvest.
Best Cabbage Varieties for Boise, ID
Consult a Boise-area nursery or your state extension office for cabbage varieties proven in Zone 5a.
Growing Cabbage in Boise
Boise sits in Zone 5a, with an average last frost of April 15 and first fall frost around October 15 — giving a 183-day frost-free growing season. Cool-season crops like cabbage benefit from Boise's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
Boise's cooler summers are close to ideal for cabbage. The same conditions that limit tomato and pepper yields benefit cool-season crops — slower bolting, sweeter flavor, and longer harvest windows. The fall cabbage crop in Boise is often more productive than the spring crop.
Boise's well-draining loam soils are among the best for cabbage growing — focus on annual organic matter additions (2 to 3 inches of compost) and consistent moisture during drier months. Water cabbage 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.
Cabbage Calendar for Boise
| Month | Task |
|---|---|
| February | Start seeds indoors under grow lights |
| April | Last frost — harden off seedlings outdoors |
| March | Transplant outdoors into warm soil |
| May | Expect first harvest window to open |
| July | Start fall crop — transplants or direct sow |
| October | First fall frost — harvest remaining, end of outdoor season |
Cabbage Tips for Boise Gardeners
- •Space plants 18 inches apart — crowding reduces head size and promotes fungal disease.
- •Side-dress with nitrogen 3–4 weeks after transplanting to support rapid leaf formation.
- •Fall plantings in Boise often out-produce spring plantings — cooler temperatures slow bolting and concentrate flavor. Light frost can actually improve the taste of cabbage.
Common Cabbage Pests in Boise
- •Cabbage Worm — peaks July in Zone 5a (active June–August); green caterpillars on brassicas; apply Bt spray or use row covers.
- •Cabbage Looper — peaks July in Zone 5a (active June–August); loop-walking green caterpillars; Bt spray works well.
- •Aphid — peaks July in Zone 5a (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 Cabbage in Boise
In Boise's cold climate, Onion and Dill are the most beneficial plants to grow alongside cabbage. Onion deters carrot fly, aphids, and several root-zone pests through sulfur compounds. Keep cabbage 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 cabbage in Boise, ID?
In Boise (Zone 5a), start cabbage seeds indoors around February 25–March 4 and transplant outdoors around March 25–April 4. The city's average last frost of April 15 is the anchor date — count 7 weeks back for seed starting and 3 weeks back for transplanting.
What zone is Boise, ID for cabbage growing?
Boise is USDA Zone 5a. For cabbage, this means a frost-free growing season of roughly 26 weeks running from April 15 to October 15. Cool-season crops like cabbage thrive in this zone with both spring and fall planting windows available.
When is cabbage harvest season in Boise?
Expect the first cabbage harvest in Boise around May 24, with harvest continuing through July 3. This is based on 60–100 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 cabbage in Boise, ID?
From transplant or direct sow to first harvest, cabbage takes 60–100 days in Boise's climate. Based on a typical planting date of March 25–April 4, expect your first harvest around May 24. Boise's cooler Zone 5a climate often lands at the slower end of this range — cooler nights slow fruit development.
What soil does cabbage need in Boise?
Boise's loam soil is near-ideal for cabbage. 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.