When to Plant Cucumbers in Green Bay, WI
Published: April 21, 2026
Cucumber Planting Dates for Green Bay, WI
| Start seeds indoors | March 25–April 1 |
| Last frost (average) | April 15 |
| Transplant outdoors | April 22–May 2 |
| Direct sow outdoors | April 22–May 2 |
| Minimum soil temperature | 60°F |
| Expect first harvest | June 11 – July 1 |
| Fall crop planting | August 6–16 |
| Fall crop harvest | September 25 |
| First fall frost (average) | October 15 |
Best Cucumber Varieties for Green Bay, WI
For Zone 5a Green Bay, the best-performing cucumber varieties are Spacemaster, Bush Pickle, and Fanfare — all short-season varieties chosen for cool-climate reliability. Calypso is worth trialing in containers or a small plot — its extra cold tolerance gives a backup if your main crop is lost to a late spring frost. These varieties are typically stocked by local nurseries and are the safest bets for gardeners new to cucumber in Green Bay.
Growing Cucumbers in Green Bay
Green Bay 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. Warm-season crops like cucumber need soil at 60°F or above before transplanting; Green Bay's frost calendar puts that window clearly in the late-spring to early-fall range.
Green Bay's short growing season makes indoor seed starting essential for cucumber. Missing the March 25–April 1 start date by even two weeks often means plants do not reach producing size before the first fall frost shuts them down. Row covers and cold frames extend both ends of the season by 2–3 weeks each.
Green Bay's clay-loam soils are productive but benefit from annual compost amendment — 2 to 3 inches worked in before planting improves drainage and nutrient availability for cucumber. Consistent watering (1.5 inches per week) paired with organic mulch maintains the even moisture that clay-loam holds well. Avoid working wet soil in spring, which causes severe compaction in clay-loam blends.
Cucumber Calendar for Green Bay
| Month | Task |
|---|---|
| March | Start seeds indoors under grow lights |
| April | Transplant outdoors into warm soil |
| June | Expect first harvest window to open |
| August | Start fall crop — transplants or direct sow |
| October | First fall frost — harvest remaining, end of outdoor season |
Cucumber Tips for Green Bay Gardeners
- •Direct sow after last frost rather than transplanting — cucumbers establish faster from seed in warm soil.
- •Trellis vertically to save space and reduce powdery mildew from soil splash.
- •Cover transplants with floating row covers for the first 2–3 weeks after setting them out in Green Bay. The 3–5°F of extra warmth dramatically improves early establishment.
Common Cucumber Pests in Green Bay
- •Cucumber Beetle — peaks July in Zone 5a (active June–August); yellow and black striped beetles that spread bacterial wilt; trap with yellow sticky traps.
- •Squash Vine Borer — peaks July in Zone 5a (active June–August); sudden wilting with frass at stem base; inject Bt into the stem or use row covers through flowering.
- •Powdery Mildew — peaks July in Zone 5a (active June–August); white powdery coating on leaves; improve airflow and apply milk spray (1:9 milk-to-water).
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Cucumbers in Green Bay
In Green Bay's cold climate, Radish and Nasturtium are the most beneficial plants to grow alongside cucumber. Radish deters cucumber beetles and matures fast enough to harvest between slower neighbors. Keep cucumber away from Aromatic Herbs — it generally slow cucumber growth when planted too close. In short-season gardens, interplanting companions at transplant time maximizes each bed's productive weeks.
Frequently Asked Questions
When should I plant cucumber in Green Bay, WI?
In Green Bay (Zone 5a), start cucumber seeds indoors around March 25–April 1 and transplant outdoors around April 22–May 2. The city's average last frost of April 15 is the anchor date — count 3 weeks back for seed starting and 1 weeks forward for transplanting.
What zone is Green Bay, WI for cucumber growing?
Green Bay is USDA Zone 5a. For cucumber, this means a frost-free growing season of roughly 26 weeks running from April 15 to October 15. This is a tight window for warm-season crops like cucumber — short-season varieties maximize harvest.
When is cucumber harvest season in Green Bay?
Expect the first cucumber harvest in Green Bay around June 11, with harvest continuing through July 1. This is based on 50–70 days from transplant or direct sow. A fall crop planted August 6–16 adds a second harvest around September 25.
How long does it take to grow cucumber in Green Bay, WI?
From transplant or direct sow to first harvest, cucumber takes 50–70 days in Green Bay's climate. Based on a typical planting date of April 22–May 2, expect your first harvest around June 11. Green Bay's cooler Zone 5a climate often lands at the slower end of this range — cooler nights slow fruit development.
What soil does cucumber need in Green Bay?
Green Bay's clay-loam soil is productive for cucumber but benefits from annual compost amendment. Work 2–3 inches of compost into the top 10 inches before planting. Avoid working wet soil in spring — clay-loam compacts badly when wet. Consistent watering paired with organic mulch maintains the even moisture these soils hold well.