When to Plant Broccoli in Riverside County, CA
This month in Riverside County, California
Each item below is timed to Riverside County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Collect broccoli at their peak
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong June, finish these tasks
- First harvests: broccoli
Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.
Riverside County, California is in USDA Zone 10a. The average last spring frost is February 24 and the first fall frost is December 4, giving you a growing season of approximately 283 days.
At an elevation of 1,206 feet, Riverside County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Broccoli may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Broccoli successfully. Mulch heavily to conserve soil moisture.
Riverside County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 Riverside County
How your county's soil matches Broccoli's growing requirements.
Soil pH
Your soil pH (6.2–7.8) overlaps with Broccoli's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Riverside County is excellent for Broccoli — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Broccoli.
How to Plant Broccoli
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Broccoli
Sow every 6.9 weeks. Last sowing by Sep 05 to harvest before frost.
For a dedicated fall crop, sow by Oct 09.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Broccoli
Broccoli needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Broccoli Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.5" | 0" | ❄️ Dormant |
| Feb | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Mar | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Oct | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Nov | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Dec | 4.3" | 2.4" | 1.9" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Riverside County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Broccoli 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.
Broccoli Planting Timeline — Riverside County, CA
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 27 | Jan 27 – Feb 10 |
| Transplant Outdoors | February 24 | Feb 24 – Mar 10 |
| Direct Sow | February 3 | Feb 3 – Feb 24 |
| Harvest | April 28 | Apr 28 – Jun 9 |
| Fall Sowing | October 9 | Oct 9 – Oct 23 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 10a
📆 Growing Season
283 days in Riverside County
Growing Tips for Broccoli in Riverside County
Direct sow Broccoli outdoors after February 24 in Riverside County when soil has warmed and frost danger has passed.
Summer highs in Riverside County reach 102°F — grow Broccoli as a spring or fall crop. Use shade cloth if planting in summer.
Common pests for Broccoli in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Riverside County receives only 16" of rain annually. Broccoli needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.
Recommended Broccoli Varieties for Riverside County
Heat-tolerant broccoli — plant as early spring or fall crop
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.
Broccoli in Other Locations
Frequently Asked Questions
When should I plant Broccoli in Riverside County, CA?
Riverside County is in Zone 10a with an average last frost of February 24. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.
What planting zone is Riverside County, CA?
Riverside County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 24 and first fall frost is December 4.
Your Riverside County Garden Planner — Free
A 24-page printable planner built for Riverside County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.