Blog

When to Plant Cress in Twin Falls County, ID

Garden cress is one of the fastest-growing edibles, producing peppery sprouts in as little as two weeks. It is excellent for microgreens and garnishes.

Twin Falls County, Idaho is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 4,584 feet, Twin Falls County receives approximately 21.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Cress during the growing season.

Twin Falls County, ID (Zone 6a) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4

Twin Falls County Soil Profile

Soil Type

Loam

Soil pH

6.5-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (115 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: May 15 – Jun 5
Recommended (50%) ✓ Fits season (112 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: May 24 – Jun 14
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Apr 30 Transplant: Jun 4 🍅 Harvest: Jun 18 – Jul 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
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 592 gal / 100 sq ft
Drought risk

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

Cress needs ~254 GDD — county provides 2,131 GDD Excellent fit

Cress Planting Timeline โ€” Twin Falls County, ID

Cress Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 โ€“ Apr 19
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow April 26 Apr 26 โ€“ May 17
Fall Sowing July 26 Jul 26 โ€“ Aug 9
Harvest May 24 May 24 โ€“ Jun 14

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

14โ€“21 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

147 days

Growing Tips for Twin Falls County

Sow seeds thickly on moist soil or paper towels. Keep moist and harvest when 2-3 inches tall. Succession sow every few days for continuous supply. Grows well indoors year-round.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Cress in Twin Falls County, ID?

Twin Falls County is in Zone 6a with an average last frost of May 10. Plan your Cress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Twin Falls County, ID?

Twin Falls County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Twin Falls County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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