When to Plant Radish in San Benito County, CA
Your May planting checklist for San Benito County, California
Your San Benito County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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 Benito County, California is in USDA Zone 9b. The average last spring frost is February 21 and the first fall frost is November 29, giving you a growing season of approximately 281 days.
At an elevation of 149 feet, San Benito County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Radish during the growing season. With low rainfall, drip irrigation is essential for growing Radish successfully. Mulch heavily to conserve soil moisture.
San Benito County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.4
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 Benito County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (6.5–7.4) overlaps with Radish's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in San Benito County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Radish.
How to Plant Radish
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Radish
Sow every 2.4 weeks. Last sowing by Oct 25 to harvest before frost.
For a dedicated fall crop, sow by Oct 04.
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 | — | 2.5" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| May | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Jun | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Oct | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Nov | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in San Benito 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 Benito County, CA
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | January 31 | Jan 31 – Feb 21 |
| Harvest | February 28 | Feb 28 – Mar 21 |
| Fall Sowing | October 4 | Oct 4 – Oct 18 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Direct Sow |
| February | Direct Sow Harvest |
| March | Harvest |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| 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: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
281 days in San Benito County
Growing Tips for Radish in San Benito County
Direct sow Radish outdoors after February 21 in San Benito County when soil has warmed and frost danger has passed.
Summer highs in San Benito County reach 94°F — grow Radish as a spring or fall crop. Use shade cloth if planting in summer.
Your generous 282.0-day season in San Benito 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 Benito County, CA?
San Benito County is in Zone 9b with an average last frost of February 21. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Benito County, CA?
San Benito County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 21 and first fall frost is November 29.
Your San Benito County Garden Planner — Free
A 24-page printable planner built for San Benito County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.