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When to Plant Watercress in Daniels County, MT

Daniels County, Montana Zone 3b May

This month in Daniels County, Montana

Each item below is timed to Daniels County, Montana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 20
Avg. first frost September 16
Soil temp (4") 33°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Get watercress in the ground

    Frost risk is low now in Daniels County, Montana. If you've been covering beds overnight, you can stop.

  2. Seed watercress outdoors

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

June will be here before you know it — start on
  • Fall sowing: watercress

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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.

Daniels County, Montana is in USDA Zone 3b. The average last spring frost is May 20 and the first fall frost is September 16, giving you a growing season of approximately 119 days.

At an elevation of 6,023 feet, Daniels County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Watercress to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Watercress successfully. Mulch heavily to conserve soil moisture.

Daniels County, MT (Zone 3b) Short season
119 days
Last Spring Frost May 20
119 growing days
First Fall Frost September 16
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Daniels 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 (40 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Jun 25 – Jul 30
Recommended (50%) ✓ Fits season (42 days to spare)
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Jul 1 – Aug 5
Safe Start (90%) ✓ Fits season (34 days to spare)
Start indoors: Apr 28 Transplant: Jun 9 🍅 Harvest: Jul 21 – Aug 25

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 Daniels County

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

Soil pH

Your soil pH (6.3–7.8) overlaps with Watercress's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Watercress.

How to Plant Watercress

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Watercress

3
successive plantings in your 119-day season

Sow every 4.6 weeks. Last sowing by Jul 18 to harvest before frost.

For a dedicated fall crop, sow by Jun 24.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,211 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Watercress

Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watercress Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 6.5" 1.9" 4.6" 🚿 Regular watering
Jun 6.5" 1.1" 5.4" 🚿 Regular watering
Jul 6.5" 1.2" 5.3" 🚿 Regular watering
Aug 6.5" 1.6" 4.9" 🚿 Regular watering
Sep 6.5" 1.3" 5.2" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Watercress 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.

Watercress needs ~425 GDD — county provides 1,011 GDD Excellent fit

Watercress Planting Timeline — Daniels County, MT

Watercress Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 13 May 13 – Jun 3
Harvest July 1 Jul 1 – Aug 5
Fall Sowing June 24 Jun 24 – Jul 8

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 3b

📆 Growing Season

119 days in Daniels County

Growing Tips for Watercress in Daniels County

Direct sow Watercress outdoors after May 20 in Daniels County when soil has warmed and frost danger has passed.

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

Daniels County receives only 16" of rain annually. Watercress needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watercress in Daniels County, MT?

Daniels County is in Zone 3b with an average last frost of May 20. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Daniels County, MT?

Daniels County, Montana is in USDA Hardiness Zone 3b. The average last spring frost is May 20 and first fall frost is September 16.

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Your Daniels County Garden Planner — Free

A 24-page printable planner built for Daniels County (Zone 3b). 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 Daniels County, MT. 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.