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When to Plant Cress in Garfield County, CO

Garfield County, Colorado Zone 6a May

Your May planting checklist for Garfield County, Colorado

May is a pivotal month for Garfield County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 25
Avg. first frost September 21
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Time to transplant cress

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Direct-sow cress

    Your soil is 35°F — warm enough for these to germinate without babying.

Get ahead of June
  • Starting indoors: cress
  • First harvests: 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.

Garfield County, Colorado is in USDA Zone 6a. The average last spring frost is May 25 and the first fall frost is September 21, giving you a growing season of approximately 119 days.

At an elevation of 7,997 feet, Garfield County receives approximately 21.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Cress to ensure they mature before fall.

Garfield County, CO (Zone 6a) Short season
119 days
Last Spring Frost May 25
119 growing days
First Fall Frost September 21

Garfield County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: May 28 – Jun 18
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Apr 20 Transplant: May 25 🍅 Harvest: Jun 8 – Jun 29
Safe Start (90%) ✓ Fits season (81 days to spare)
Start indoors: May 10 Transplant: Jun 14 🍅 Harvest: Jun 28 – Jul 19

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 Garfield County

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

Soil pH

Your soil pH (6.5–7.9) is more alkaline than Cress prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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

10
successive plantings in your 119-day season

Sow every 1.6 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 315 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Garfield 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 ~228 GDD — county provides 1,547 GDD Excellent fit

Cress Planting Timeline — Garfield County, CO

Cress Planting Calendar

Activity When Date Range
Start Indoors April 20 Apr 20 – May 4
Transplant Outdoors May 25 May 25 – Jun 8
Direct Sow May 11 May 11 – Jun 1
Harvest June 8 Jun 8 – Jun 29
Fall Sowing July 13 Jul 13 – Jul 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

14–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

119 days in Garfield County

Growing Tips for Cress in Garfield County

Direct sow Cress outdoors after May 25 in Garfield County when soil has warmed and frost danger has passed.

Your generous 119.0-day season in Garfield 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.

Garfield County receives only 21" 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 Garfield County, CO?

Garfield County is in Zone 6a with an average last frost of May 25. Plan your Cress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Garfield County, CO?

Garfield County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 25 and first fall frost is September 21.

🌱

Your Garfield County Garden Planner — Free

A 24-page printable planner built for Garfield 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 Garfield County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

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