When to Plant Stevia in San Diego County, CA
May in the garden — San Diego County, California
Your garden in San Diego County, California is working on a schedule, even when you're not. Here's where you should be this May.
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Begin indoor sowing: stevia
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
June prep starts now
- First harvests: stevia
Stevia is a subtropical herb whose leaves contain natural sweeteners 200-300 times sweeter than sugar. It is grown as an annual in most climates.
San Diego County, California is in USDA Zone 10b. The average last spring frost is April 16 and the first fall frost is November 1, giving you a growing season of approximately 199 days.
At an elevation of 2,613 feet, San Diego County receives approximately 18.2 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Stevia during the growing season. With low rainfall, drip irrigation is essential for growing Stevia successfully. Mulch heavily to conserve soil moisture.
San Diego County Soil Profile
Soil Type
Loam
Soil pH
5.7-7.5
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 Diego County
How your county's soil matches Stevia's growing requirements.
Soil pH
Your soil pH (5.7–7.5) overlaps with Stevia's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in San Diego County is excellent for Stevia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Stevia.
How to Plant Stevia
Succession Planting Stevia
Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Stevia
Stevia 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 | Stevia Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| May | 2.2" | 0.5" | 1.7" | 🚿 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" | 0.2" | 2" | 🚿 Regular watering |
| Oct | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Nov | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in San Diego County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Stevia 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.
Stevia Planting Timeline — San Diego County, CA
Stevia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 5 | Mar 5 – Mar 19 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Harvest | June 25 | Jun 25 – Sep 3 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 10b
📆 Growing Season
199 days in San Diego County
Growing Tips for Stevia in San Diego County
Direct sow Stevia outdoors after April 16 in San Diego County when soil has warmed and frost danger has passed.
Common pests for Stevia in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors under lights or buy transplants. Pinch flowers to encourage leaf production. Harvest leaves before flowering for maximum sweetness. Dry leaves for year-round use.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Stevia in Other Locations
Frequently Asked Questions
When should I plant Stevia in San Diego County, CA?
San Diego County is in Zone 10b with an average last frost of April 16. Plan your Stevia planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Diego County, CA?
San Diego County, California is in USDA Hardiness Zone 10b. The average last spring frost is April 16 and first fall frost is November 1.
Your San Diego County Garden Planner — Free
A 24-page printable planner built for San Diego County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.