When to Plant Radish in Lake County, CA
Top priorities for Lake County, California gardeners in May
Here's what deserves your attention in Lake County, California this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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.
Lake County, California is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.
At an elevation of 154 feet, Lake County receives approximately 30.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 83°F, so choose short-season varieties of Radish to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Radish will need more frequent watering and organic matter to retain nutrients.
Lake County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.1-6.9
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 Lake County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (6.1–6.9) is within Radish's preferred range (6.0–7.0).
Soil Texture
Sandy soil in Lake County warms quickly in spring but drains fast. Radish will need more frequent watering and regular compost additions to retain nutrients.
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 23 to harvest before frost.
For a dedicated fall crop, sow by Oct 02.
Plant Water Budget
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 | — | 6.2" | 0" | ❄️ Dormant |
| Feb | — | 6.5" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Jun | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Oct | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Nov | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 5.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Lake 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 — Lake County, CA
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | February 9 | Feb 9 – Mar 2 |
| Harvest | March 9 | Mar 9 – Mar 30 |
| Fall Sowing | October 2 | Oct 2 – Oct 16 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Direct Sow |
| March | Direct Sow Harvest |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| 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: ideal
🗺️ USDA Zone
Zone 9a
📆 Growing Season
270 days in Lake County
Growing Tips for Radish in Lake County
Direct sow Radish outdoors after March 02 in Lake County when soil has warmed and frost danger has passed.
Sandy soil in Lake 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 270.0-day season in Lake 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 Lake County, CA?
Lake County is in Zone 9a with an average last frost of March 2. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lake County, CA?
Lake County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 27.
Your Lake County Garden Planner — Free
A 24-page printable planner built for Lake County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.