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When to Plant Guava in San Bernardino County, CA

San Bernardino County, California Zone 10a May

Your May game plan for San Bernardino County, California

Each item below is timed to San Bernardino County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 24
Avg. first frost November 25
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs

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Guava is a tropical fruit tree producing fragrant, vitamin C-rich fruits with pink, white, or yellow flesh. Some varieties can tolerate brief cold snaps.

San Bernardino County, California is in USDA Zone 10a. The average last spring frost is February 24 and the first fall frost is November 25, giving you a growing season of approximately 274 days.

At an elevation of 1,012 feet, San Bernardino County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 97°F, so Guava may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Guava successfully. Mulch heavily to conserve soil moisture.

San Bernardino County, CA (Zone 10a) Year-round
274 days
Last Spring Frost February 24
274 growing days
First Fall Frost November 25
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San Bernardino County Soil Profile

Soil Type

Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Feb 27
Recommended (50%) ✓ Fits season
Transplant: Mar 10
Safe Start (90%) ✓ Fits season
Transplant: Mar 21

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 Bernardino County

How your county's soil matches Guava's growing requirements.

Soil pH

Your soil pH (5.9–7.2) overlaps with Guava's range (5.0–7.0), though not a perfect match.

Soil Texture

The loam soil in San Bernardino County is excellent for Guava — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Guava.

How to Plant Guava

36"
Between Plants
48"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,179 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Guava

Guava needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Guava Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 4.3" 3.8" 0.5" 💧 Light watering
Mar 4.3" 2.2" 2.1" 💧 Light watering
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 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" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.7" 2.6" 🚿 Regular watering
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in San Bernardino County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Guava 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.

Guava needs ~12,456 GDD — county provides 6,256 GDD May not mature

Guava Planting Timeline — San Bernardino County, CA

Guava Planting Calendar

Activity When Date Range
Transplant Outdoors March 10 Mar 10 – Mar 24

· 36" apart · Rows 48" apart

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April
May
June
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

274 days in San Bernardino County

Growing Tips for Guava in San Bernardino County

Direct sow Guava outdoors after February 24 in San Bernardino County when soil has warmed and frost danger has passed.

With summer highs reaching 97°F in San Bernardino County, provide afternoon shade for Guava and water deeply in the morning.

Your 275.0-day growing season in San Bernardino County is tight for Guava (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

San Bernardino County receives only 17" of rain annually. Guava needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant in a sheltered location with full sun. Water regularly during fruiting. In marginal zones, grow in large containers. Prune to maintain size and shape. Fruits ripen year-round in the tropics.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Guava in San Bernardino County, CA?

San Bernardino County is in Zone 10a with an average last frost of February 24. Plan your Guava planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Bernardino County, CA?

San Bernardino County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 24 and first fall frost is November 25.

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Your San Bernardino County Garden Planner — Free

A 24-page printable planner built for San Bernardino 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for San Bernardino County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.