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When to Plant Watercress in Lea County, NM

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.

Lea County, New Mexico is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 7, giving you a growing season of approximately 219 days.

At an elevation of 4,857 feet, Lea County receives approximately 17.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 93ยฐF, providing good warmth for Watercress during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Watercress will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Watercress successfully. Mulch heavily to conserve soil moisture.

Lea County, NM (Zone 7b) Long season
219 days
Last Spring Frost April 2
219 growing days
First Fall Frost November 7

Lea County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (140 days to spare)
Start indoors: Feb 17 Transplant: Mar 24 🍅 Harvest: May 5 – Jun 9
Recommended (50%) ✓ Fits season (142 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: May 14 – Jun 18
Safe Start (90%) ✓ Fits season (135 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 2 – Jul 7

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 Lea County

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

Soil pH

Your soil pH (7.3โ€“8.9) is more alkaline than Watercress prefers (6.5โ€“7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Lea County warms quickly in spring but drains fast. Watercress will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Watercress is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Watercress.

How to Plant Watercress

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

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

Succession Planting Watercress

6
successive plantings in your 219-day season

Sow every 4.6 weeks. Last sowing by Sep 08 to harvest before frost.

For a dedicated fall crop, sow by Aug 29.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.3″/week
You supply
2.0″/week
Watering frequency 2-3 times/week
Season total 3,794 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” 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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 0.8" 0" โ„๏ธ Dormant
Apr 6.5" 0.6" 5.9" ๐Ÿšฟ Regular watering
May 6.5" 0.3" 6.2" ๐Ÿšฟ Regular watering
Jun 6.5" 0.5" 6" ๐Ÿšฟ Regular watering
Jul 6.5" 2.9" 3.6" ๐Ÿšฟ Regular watering
Aug 6.5" 3.7" 2.8" ๐Ÿ’ง Light watering
Sep 6.5" 2.4" 4.1" ๐Ÿšฟ Regular watering
Oct 6.5" 1.6" 4.9" ๐Ÿšฟ Regular watering
Nov 6.5" 1.1" 5.4" ๐Ÿšฟ Regular watering
Dec โ€” 1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Lea County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~988 GDD — county provides 4,325 GDD Excellent fit

Watercress Planting Timeline โ€” Lea County, NM

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 โ€“ Mar 12
Transplant Outdoors April 2 Apr 2 โ€“ Apr 16
Direct Sow March 19 Mar 19 โ€“ Apr 9
Harvest May 14 May 14 โ€“ Jun 18
Fall Sowing August 29 Aug 29 โ€“ Sep 12

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

219 days in Lea County

Growing Tips for Watercress in Lea County

Direct sow Watercress outdoors after April 02 in Lea County when soil has warmed and frost danger has passed.

Sandy soil in Lea County dries quickly โ€” mulch Watercress with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 219.0-day season in Lea County allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.

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

Lea County receives only 17" of rain annually. Watercress needs consistent moisture โ€” 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 Lea County, NM?

Lea County is in Zone 7b with an average last frost of April 2. Plan your Watercress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lea County, NM?

Lea County, New Mexico is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lea County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Lea County, NM. Local conditions may vary. Last updated: April 2026.