Blog

When to Plant Radish in Harding County, NM

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

Harding County, New Mexico is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 8, giving you a growing season of approximately 159 days.

At an elevation of 6,903 feet, Harding County receives approximately 13 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Radish to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Radish will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Radish successfully. Mulch heavily to conserve soil moisture.

Harding County, NM (Zone 5b) Moderate season
159 days
Last Spring Frost May 2
159 growing days
First Fall Frost October 8

Harding County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Transplant: Apr 28 🍅 Harvest: May 26 – Jun 16
Recommended (50%) ✓ Fits season (110 days to spare)
Transplant: May 2 🍅 Harvest: May 30 – Jun 20
Safe Start (90%) ✓ Fits season (103 days to spare)
Transplant: May 19 🍅 Harvest: Jun 16 – 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 Harding County

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

Soil pH

Your soil pH (7.2โ€“8.8) is more alkaline than Radish prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Radish.

Organic Matter

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

How to Plant Radish

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 Radish

9
successive plantings in your 159-day season

Sow every 2.4 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Jul 30.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 521 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Radish

Radish needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Radish Needs Rainfall You Supplement Action
Jan โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 0.7" 0" โ„๏ธ Dormant
Apr โ€” 0.4" 0" โ„๏ธ Dormant
May 2.2" 0.3" 1.9" ๐Ÿšฟ Regular watering
Jun 2.2" 0.5" 1.7" ๐Ÿšฟ Regular watering
Jul 2.2" 2.2" 0" โœ… Rainfall sufficient
Aug 2.2" 2.7" 0" โœ… Rainfall sufficient
Sep 2.2" 1.8" 0.4" ๐Ÿ’ง Light watering
Oct 2.2" 1.3" 0.9" ๐Ÿ’ง Light watering
Nov โ€” 0.6" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Harding County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Radish 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.

Radish needs ~370 GDD — county provides 2,067 GDD Excellent fit

Radish Planting Timeline โ€” Harding County, NM

Radish Planting Calendar

Activity When Date Range
Direct Sow April 18 Apr 18 โ€“ May 9
Harvest May 16 May 16 โ€“ Jun 6
Fall Sowing July 30 Jul 30 โ€“ Aug 13

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

159 days in Harding County

Growing Tips for Radish in Harding County

Direct sow Radish outdoors after May 02 in Harding County when soil has warmed and frost danger has passed.

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

Your generous 159.0-day season in Harding County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.

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

General growing tips

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Harding County, NM?

Harding County is in Zone 5b with an average last frost of May 2. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harding County, NM?

Harding County, New Mexico is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harding County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Harding County, NM. Local conditions may vary. Last updated: April 2026.