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When to plant Snapdragon in San Bernardino County County,

Plant Snapdragon in San Bernardino County County, when soil hits 50°F — usually December 16. Continue planting through January 6 for the spring crop. A second sowing from August 19 to September 2 extends the harvest into fall.

When to Plant Snapdragon in San Bernardino County, CA

San Bernardino County, California Zone 10a June

June in the garden — San Bernardino County, California

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 24
Avg. first frost November 25
Soil temp (4") 86°F
Watering Critical
Pest pressure High
Daylight 14.3 hrs
  1. Bring in the snapdragon

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

A few tasks this June that'll pay off in July
  • First harvests: snapdragon

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Snapdragons (Antirrhinum majus) are classic cool-season annuals whose upright spikes of dragon-lipped flowers are among spring's most dramatic displays. Tolerating light frosts, they bloom from early spring until summer heat shuts them down — then often revive in fall. In zones 9-11 they are grown as fall-planted winter annuals and may re-seed to naturalize.

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 Snapdragon may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Snapdragon successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
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

Snapdragon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Transplant: Jan 2 🌸 Bloom: Mar 6 – Jul 31
Recommended (50%) ✓ Fits season (106 days to spare)
Transplant: Jan 13 🌸 Bloom: Mar 17 – Aug 11
Safe Start (90%) ✓ Fits season (109 days to spare)
Transplant: Jan 24 🌸 Bloom: Mar 28 – Aug 22

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 Snapdragon's growing requirements.

Soil pH

Your soil pH (5.9–7.2) overlaps with Snapdragon's range (6.2–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Snapdragon

9"
Between Plants
12"
Between Rows

Fall planting: Sow 14 weeks before your first frost date for a fall harvest.

Succession Planting Snapdragon

4
successive plantings in your 274-day season

Sow every 8 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 19.

Snapdragon 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 Snapdragon

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

Month Snapdragon 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.

Snapdragon 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.

Snapdragon needs ~1,934 GDD — county provides 6,256 GDD Excellent fit

Snapdragon Planting Timeline — San Bernardino County, CA

Snapdragon Planting Calendar

Activity When Date Range
Transplant Outdoors January 13 Jan 13 – Jan 27
Direct Sow December 16 Dec 16 – Jan 6
Bloom March 17 Mar 17 – Aug 11
Fall Sowing August 19 Aug 19 – Sep 2

· 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Transplant Outdoors Direct Sow
February
March Bloom
April Bloom
May Bloom
June Bloom
July Bloom
August Fall Sowing Bloom
September Fall Sowing
October
November
December Direct Sow
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6.2–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

274 days in San Bernardino County

Growing Tips for Snapdragon in San Bernardino County

Direct sow Snapdragon 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 Snapdragon and water deeply in the morning.

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

General growing tips

Start indoors 10-12 weeks before last frost; seeds need light to germinate — press into moist medium and do not cover. Transplant after hardening off, even if light frosts remain. Pinch seedlings once to encourage branching. Deadhead to prolong blooming. In zones 8-11, sow in fall for a winter-to-spring show. Tall varieties (24-36") make excellent cut flowers.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

San Bernardino County is in Zone 10a with an average last frost of February 24. Plan your Snapdragon 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.

When should I plant Snapdragon in San Bernardino County County, ?

In San Bernardino County County, , plant Snapdragon after the last frost (around February 24) and before the first frost (around November 25). Best results when soil holds above 50°F.

What growing zone is San Bernardino County County, for Snapdragon?

San Bernardino County County sits in USDA Zone 10a. Snapdragon grows reliably in zones 2a through 11b, so it's a good fit here.

Can Snapdragon grow in San Bernardino County County's climate?

Yes — Snapdragon grows well in San Bernardino County County's temperate climate. San Bernardino County County averages a 275-day frost-free season, with last frost around February 24 and first frost around November 25.

🌱

Your San Bernardino County Garden Planner — Free

A 22-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: June 2026.

Sources & credits

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