When to Plant Goji Berries in San Mateo County, CA
Your May planting checklist for San Mateo County, California
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in San Mateo County, California.
Goji berries are a deciduous shrub producing small, bright red berries valued as a superfood. The plants are extremely hardy and drought-tolerant once established.
San Mateo County, California is in USDA Zone 10a. The average last spring frost is January 18 and the first fall frost is December 12, giving you a growing season of approximately 328 days.
At an elevation of 277 feet, San Mateo County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Goji Berries to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Goji Berries successfully. Mulch heavily to conserve soil moisture.
San Mateo County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
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 Mateo County
How your county's soil matches Goji Berries's growing requirements.
Soil pH
Your soil pH (6.8–7.2) is within Goji Berries's preferred range (6.5–8.0).
Soil Texture
The loam soil in San Mateo County is excellent for Goji Berries — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Goji Berries.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Goji Berries.
How to Plant Goji Berries
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Goji Berries
Goji Berries 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 | Goji Berries Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Feb | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.2" | 1" | 💧 Light watering |
| May | 2.2" | 0.4" | 1.8" | 🚿 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" | 0.7" | 1.5" | 🚿 Regular watering |
| Nov | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Dec | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Jan–Dec in San Mateo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Goji Berries 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.
Goji Berries Planting Timeline — San Mateo County, CA
Goji Berries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 1 | Feb 1 – Feb 15 |
· 48" apart · Rows 72" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 6.5–8 · Your soil: ideal
🗺️ USDA Zone
Zone 10a
📆 Growing Season
328 days in San Mateo County
Growing Tips for Goji Berries in San Mateo County
Direct sow Goji Berries outdoors after January 18 in San Mateo County when soil has warmed and frost danger has passed.
Your 329.0-day growing season in San Mateo County is tight for Goji Berries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Goji Berries in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
San Mateo County receives only 17" of rain annually. Goji Berries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Plant in well-drained soil in full sun. Prune annually to manage the arching, somewhat wild growth habit. Berries ripen over an extended period in summer and fall. Can be trellised.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Goji Berries in Other Locations
Frequently Asked Questions
When should I plant Goji Berries in San Mateo County, CA?
San Mateo County is in Zone 10a with an average last frost of January 18. Plan your Goji Berries planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Mateo County, CA?
San Mateo County, California is in USDA Hardiness Zone 10a. The average last spring frost is January 18 and first fall frost is December 12.
Your San Mateo County Garden Planner — Free
A 24-page printable planner built for San Mateo 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.