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When to Plant Dill in San Bernardino County, CA

San Bernardino County, California Zone 10a May

May in the garden — San Bernardino County, California

A quick May briefing for San Bernardino County, California gardeners — what's urgent, what's next, and what can wait.

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

    If you can't use it all right away, check the food-preservation section of your planner.

To set up a strong June, finish these tasks
  • First harvests: dill

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Dill is a feathery annual herb with aromatic leaves and seeds. Its fine foliage and umbrella-shaped flower heads attract beneficial insects to the garden.

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 Dill may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Dill 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

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 (182 days to spare)
Start indoors: Jan 16 Transplant: Feb 6 🍅 Harvest: Mar 20 – May 22
Recommended (50%) ✓ Fits season (176 days to spare)
Start indoors: Jan 27 Transplant: Feb 17 🍅 Harvest: Mar 31 – Jun 2
Safe Start (90%) ✓ Fits season (179 days to spare)
Start indoors: Feb 7 Transplant: Feb 28 🍅 Harvest: Apr 11 – Jun 13

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 Dill's growing requirements.

Soil pH

Your soil pH (5.9–7.2) overlaps with Dill's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Dill

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Dill

8
successive plantings in your 274-day season

Sow every 4.6 weeks. Last sowing by Sep 26 to harvest before frost.

For a dedicated fall crop, sow by Sep 30.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 710 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Dill

Dill 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 Dill Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 2.2" 3.8" 0" ✅ Rainfall sufficient
Mar 2.2" 2.2" 0" ✅ Rainfall sufficient
Apr 2.2" 1.5" 0.7" 💧 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" 0.7" 1.5" 🚿 Regular watering
Nov 2.2" 1.7" 0.5" 💧 Light 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.

Dill 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.

Dill needs ~1,138 GDD — county provides 6,256 GDD Excellent fit

Dill Planting Timeline — San Bernardino County, CA

Dill Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors February 17 Feb 17 – Mar 3
Direct Sow February 3 Feb 3 – Feb 24
Harvest March 31 Mar 31 – Jun 2
Fall Sowing September 30 Sep 30 – Oct 14

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors Transplant Outdoors Direct Sow
March Transplant Outdoors Harvest
April Harvest
May Harvest
June Harvest
July
August
September Fall Sowing
October Fall Sowing
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

274 days in San Bernardino County

Growing Tips for Dill in San Bernardino County

Direct sow Dill 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 Dill and water deeply in the morning.

Your generous 275.0-day season in San Bernardino County allows multiple plantings of Dill. Sow every 20.0 days for continuous harvest.

Common pests for Dill in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring as dill has a taproot and dislikes transplanting. Succession sow for continuous leaf harvest. Allow some plants to flower for seeds and to attract beneficial insects.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

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

🌱

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.