When to Plant Radish in San Juan County, NM
Your May planting checklist for San Juan County, New Mexico
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in San Juan County, New Mexico.
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Pick radish
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Get ahead of June
- 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.
San Juan County, New Mexico is in USDA Zone 7a. The average last spring frost is May 12 and the first fall frost is October 6, giving you a growing season of approximately 147 days.
At an elevation of 8,301 feet, San Juan County receives approximately 14.3 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.
San Juan County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.3-8.5
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 San Juan County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (7.3–8.5) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in San Juan 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
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 01 to harvest before frost.
For a dedicated fall crop, sow by Jul 28.
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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.5" | 0" | ❄️ Dormant |
| May | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Jun | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Jul | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in San Juan 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 — San Juan County, NM
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | May 26 | May 26 – Jun 16 |
| Fall Sowing | July 28 | Jul 28 – Aug 11 |
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 · Only during dry spells
📅 Days to Maturity
22–35 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
147 days in San Juan County
Growing Tips for Radish in San Juan County
Direct sow Radish outdoors after May 12 in San Juan County when soil has warmed and frost danger has passed.
Sandy soil in San Juan 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 147.0-day season in San Juan 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 San Juan County, NM?
San Juan County is in Zone 7a with an average last frost of May 12. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Juan County, NM?
San Juan County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 12 and first fall frost is October 6.
Your San Juan County Garden Planner — Free
A 24-page printable planner built for San Juan 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.