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When to Plant Cucumber in Latah County, ID

Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

Latah County, Idaho is in USDA Zone 5b. The average last spring frost is May 11 and the first fall frost is September 23, giving you a growing season of approximately 135 days.

At an elevation of 5,530 feet, Latah County receives approximately 14.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Cucumber during the growing season. With low rainfall, drip irrigation is essential for growing Cucumber successfully. Mulch heavily to conserve soil moisture.

Latah County, ID (Zone 5b) Short season
135 days
Last Spring Frost May 11
135 growing days
First Fall Frost September 23

Latah County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Start indoors: Mar 30 Transplant: May 18 🍅 Harvest: Jul 13 – Sep 7
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 6 Transplant: May 25 🍅 Harvest: Jul 20 – Sep 14
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: May 1 Transplant: Jun 19 🍅 Harvest: Aug 14 – Oct 9

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.8″/week
Watering frequency 2-3 times/week
Season total 2,148 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Cucumber needs ~870 GDD — county provides 1,957 GDD Excellent fit

Cucumber Planting Timeline โ€” Latah County, ID

Cucumber Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 โ€“ Apr 20
Transplant Outdoors May 25 May 25 โ€“ Jun 8
Direct Sow May 18 May 18 โ€“ Jun 8
Harvest July 20 Jul 20 โ€“ Sep 14

Plant 0.5" deep ยท 24" apart ยท Rows 48" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

50โ€“70 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

135 days

Growing Tips for Latah County

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Level Up Your Garden

Frequently Asked Questions

When should I plant Cucumber in Latah County, ID?

Latah County is in Zone 5b with an average last frost of May 11. Plan your Cucumber planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Latah County, ID?

Latah County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 11 and first fall frost is September 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Latah County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Latah County, ID. Local conditions may vary. Last updated: April 2026.