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When to Plant Cress in Owyhee County, ID

Owyhee County, Idaho Zone 6a April

April in the garden — Owyhee County, Idaho

Your garden in Owyhee County, Idaho is working on a schedule, even when you're not. Here's where you should be this April.

Avg. last frost June 9
Avg. first frost September 20
Soil temp (4") 39°F
Watering High
Pest pressure Low
Daylight 13.2 hrs
A few tasks this April that'll pay off in May
  • Direct-sowing: cress

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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.

Owyhee County, Idaho is in USDA Zone 6a. The average last spring frost is June 9 and the first fall frost is September 20, giving you a growing season of approximately 103 days.

At an elevation of 4,621 feet, Owyhee County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Cress during the growing season. With low rainfall, drip irrigation is essential for growing Cress successfully. Mulch heavily to conserve soil moisture.

Owyhee County, ID (Zone 6a) Short season
103 days
Last Spring Frost June 9
103 growing days
First Fall Frost September 20

Owyhee County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Start indoors: Apr 27 Transplant: Jun 1 🍅 Harvest: Jun 15 – Jul 6
Recommended (50%) ✓ Fits season (68 days to spare)
Start indoors: May 5 Transplant: Jun 9 🍅 Harvest: Jun 23 – Jul 14
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: May 15 Transplant: Jun 19 🍅 Harvest: Jul 3 – Jul 24

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.

Soil Compatibility in Owyhee County

How your county's soil matches Cress's growing requirements.

Soil pH

Your soil pH (6.3–7.8) is more alkaline than Cress prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Owyhee County is excellent for Cress — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Cress.

How to Plant Cress

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Cress

9
successive plantings in your 103-day season

Sow every 1.6 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 288 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cress

Cress needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cress Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.3" 0" ❄️ Dormant
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Owyhee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cress Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Cress needs ~306 GDD — county provides 1,802 GDD Excellent fit

Cress Planting Timeline — Owyhee County, ID

Cress Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 – May 19
Transplant Outdoors June 9 Jun 9 – Jun 23
Direct Sow May 26 May 26 – Jun 16
Harvest June 23 Jun 23 – Jul 14
Fall Sowing July 12 Jul 12 – Jul 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

14–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

103 days in Owyhee County

Growing Tips for Cress in Owyhee County

Direct sow Cress outdoors after June 09 in Owyhee County when soil has warmed and frost danger has passed.

Your generous 103.0-day season in Owyhee County allows multiple plantings of Cress. Sow every 7.0 days for continuous harvest.

Common pests for Cress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Owyhee County receives only 18" of rain annually. Cress needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cress in Owyhee County, ID?

Owyhee County is in Zone 6a with an average last frost of June 9. Plan your Cress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Owyhee County, ID?

Owyhee County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is June 9 and first fall frost is September 20.

🌱

Your Owyhee County Garden Planner — Free

A 24-page printable planner built for Owyhee County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Owyhee County, ID. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.