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When to plant Celosia in Solano County, CA

Plant Celosia in Solano County, when soil hits 50°F — usually January 19. Continue planting through February 9 for the spring crop.

When to Plant Celosia in Solano County, CA

Solano County, California Zone 9b June

Your June game plan for Solano County, California

A quick June briefing for Solano County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 9
Avg. first frost December 3
Soil temp (4") 85°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Pick celosia

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to July
  • First harvests: celosia

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Celosia (Celosia argentea) encompasses the vivid cockscomb (cristata) and feathery plumed (plumosa) types that explode with color in summer heat. Drought-tolerant and disease-resistant, they thrive in the hottest parts of the season and produce long-lasting blooms both in the garden and as cut or dried flowers. A reliable filler in sunny annual beds.

Solano County, California is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.

At an elevation of 376 feet, Solano County receives approximately 40.4 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Celosia may need afternoon shade and extra watering during peak heat.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Solano County, CA (Zone 9b) Year-round
297 days
Last Spring Frost February 9
297 growing days
First Fall Frost December 3

Solano County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Dec 28 Transplant: Jan 4 🌸 Bloom: Mar 8 – Sep 27
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Jan 12 Transplant: Jan 19 🌸 Bloom: Mar 23 – Oct 12
Safe Start (90%) ✓ Fits season (36 days to spare)
Start indoors: Feb 13 Transplant: Feb 20 🌸 Bloom: Apr 24 – Nov 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 Solano County

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

Soil pH

Your soil pH (6.8–7.3) is more alkaline than Celosia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Solano County is excellent for Celosia — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Celosia.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Celosia.

How to Plant Celosia

0.1"
Planting Depth
9"
Between Plants
12"
Between Rows

Succession Planting Celosia

5
successive plantings in your 297-day season

Sow every 6.9 weeks. Last sowing by Sep 04 to harvest before frost.

Celosia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 257 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Celosia

Celosia 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 Celosia Needs Rainfall You Supplement Action
Jan 8.9" 0" ❄️ Dormant
Feb 2.2" 8.4" 0" ✅ Rainfall sufficient
Mar 2.2" 6.6" 0" ✅ Rainfall sufficient
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 1" 1.2" 🚿 Regular watering
Jun 2.2" 0.2" 2" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.4" 1.8" 🚿 Regular watering
Oct 2.2" 1.9" 0.3" 💧 Light watering
Nov 2.2" 3.3" 0" ✅ Rainfall sufficient
Dec 2.2" 7.1" 0" ✅ Rainfall sufficient

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

Celosia 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.

Celosia needs ~1,594 GDD — county provides 6,332 GDD Excellent fit

Celosia Planting Timeline — Solano County, CA

Celosia Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 – Jan 26
Transplant Outdoors January 19 Jan 19 – Feb 2
Direct Sow January 19 Jan 19 – Feb 9
Bloom March 23 Mar 23 – Oct 12

Plant 0.1" deep · 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February Transplant Outdoors Direct Sow
March Bloom
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
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 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

297 days in Solano County

Growing Tips for Celosia in Solano County

Direct sow Celosia outdoors after February 09 in Solano County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 4–6 weeks before last frost, or direct-sow after soil warms above 60°F. Does not transplant well from large pots — sow in small cells or direct-sow. Needs full sun and warm soil; cold stress causes stunting. Pinch first bloom to encourage branching. Water at the base; wet foliage encourages fungal issues. Excellent dried flower — harvest before seeds set for the best color retention.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celosia in Solano County, CA?

Solano County is in Zone 9b with an average last frost of February 9. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Solano County, CA?

Solano County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 3.

When should I plant Celosia in Solano County, CA?

In Solano County, CA, plant Celosia after the last frost (around February 9) and before the first frost (around December 3). Best results when soil holds above 50°F.

What growing zone is Solano County, CA for Celosia?

Solano County sits in USDA Zone 9b. Celosia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Celosia grow in Solano County's climate?

Yes — Celosia grows well in Solano County's temperate climate. Solano County averages a 298-day frost-free season, with last frost around February 9 and first frost around December 3.

🌱

Your Solano County Garden Planner — Free

A 22-page printable planner built for Solano County (Zone 9b). 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 Solano County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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