When to Plant Radish in Los Alamos County, NM
What to do in May
A quick May briefing for Los Alamos County, New Mexico gardeners — what's urgent, what's next, and what can wait.
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Basket week: radish
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
June will be here before you know it — start on
- First harvests: radish
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.
Los Alamos County, New Mexico is in USDA Zone 7a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.
At an elevation of 5,220 feet, Los Alamos County receives approximately 12.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Radish during the growing season. Sandy soil warms quickly in spring — great for early planting — 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.
Los Alamos County Soil Profile
Soil Type
Sandy Loam
Soil pH
7-8.6
Drainage
Well Drained
Plant Planting Risk Windows
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 Los Alamos County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (7.0–8.6) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Los Alamos 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 (0.8%). Add 2-3 inches of compost before planting Radish.
How to Plant Radish
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Radish
Sow every 2.4 weeks. Last sowing by Sep 02 to harvest before frost.
For a dedicated fall crop, sow by Jul 29.
Plant Water Budget
Water stress score is 10/10 — 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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.6" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.4" | 0" | ❄️ Dormant |
| May | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Jun | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Jul | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Aug | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Oct | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Nov | — | 0.7" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Los Alamos County). Supplement amounts are based on average rainfall — 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" — 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.
Radish Planting Timeline — Los Alamos County, NM
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 26 | Apr 26 – May 17 |
| Harvest | May 24 | May 24 – Jun 14 |
| Fall Sowing | July 29 | Jul 29 – Aug 12 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow Harvest |
| June | Harvest |
| July | Fall Sowing |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
22–35 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
150 days in Los Alamos County
Growing Tips for Radish in Los Alamos County
Direct sow Radish outdoors after May 10 in Los Alamos County when soil has warmed and frost danger has passed.
Sandy soil in Los Alamos County dries quickly — mulch Radish with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your generous 150.0-day season in Los Alamos 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
Check more plant combinations with our Companion Planting Checker →
Radish in Other Locations
Frequently Asked Questions
When should I plant Radish in Los Alamos County, NM?
Los Alamos County is in Zone 7a with an average last frost of May 10. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Los Alamos County, NM?
Los Alamos County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 10 and first fall frost is October 7.
Your Los Alamos County Garden Planner — Free
A 24-page printable planner built for Los Alamos County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.