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When to Plant Watercress in Montrose County, CO

Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.

Montrose County, Colorado is in USDA Zone 6a. The average last spring frost is June 13 and the first fall frost is September 12, giving you a growing season of approximately 91 days.

At an elevation of 6,494 feet, Montrose County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Watercress during the growing season. With low rainfall, drip irrigation is essential for growing Watercress successfully. Mulch heavily to conserve soil moisture.

Montrose County, CO (Zone 6a) Very short season
91 days
Last Spring Frost June 13
91 growing days
First Fall Frost September 12

Montrose County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jun 25 – Jul 30
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Jul 25 – Aug 29
Safe Start (90%) ✓ Fits season (32 days to spare)
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Aug 7 – Sep 11

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
0.9″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 632 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Watercress needs ~762 GDD — county provides 1,387 GDD Excellent fit

Watercress Planting Timeline โ€” Montrose County, CO

Watercress Planting Calendar

Activity When Date Range
Start Indoors May 9 May 9 โ€“ May 23
Transplant Outdoors June 13 Jun 13 โ€“ Jun 27
Direct Sow May 30 May 30 โ€“ Jun 20
Fall Sowing July 4 Jul 4 โ€“ Jul 18
Harvest July 25 Jul 25 โ€“ Aug 29

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

40โ€“60 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

91 days

Growing Tips for Montrose County

Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Watercress in Montrose County, CO?

Montrose County is in Zone 6a with an average last frost of June 13. Plan your Watercress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montrose County, CO?

Montrose County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is June 13 and first fall frost is September 12.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montrose County gardeners in Zone 6a 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 Montrose County, CO. Local conditions may vary. Last updated: April 2026.