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When to plant Celosia in Glenn County, CA

For Celosia in Glenn County, the safe spring window opens around February 13 and closes around March 6. Last expected frost is March 6, first fall frost November 28, giving a 267-day growing season.

When to Plant Celosia in Glenn County, CA

Glenn County, California Zone 9b June

Glenn County, California gardeners: here's your June plan

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Glenn County, California.

Avg. last frost March 6
Avg. first frost November 28
Soil temp (4") 85°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs
  1. Start harvesting celosia

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

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.

Glenn County, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 270 feet, Glenn County receives approximately 27.1 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Celosia during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Glenn County, CA (Zone 9b) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28

Glenn County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.9

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Jan 26 Transplant: Feb 2 🌸 Bloom: Apr 6 – Oct 26
Recommended (50%) ✓ Fits season (22 days to spare)
Start indoors: Feb 6 Transplant: Feb 13 🌸 Bloom: Apr 17 – Nov 6
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: Mar 21 Transplant: Mar 28 🌸 Bloom: May 30 – Dec 19

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 Glenn County

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

Soil pH

Your soil pH (6.5–7.9) is more alkaline than Celosia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). 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 267-day season

Sow every 6.9 weeks. Last sowing by Aug 30 to harvest before frost.

Celosia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 210 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 5.6" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 2.2" 4.4" 0" ✅ Rainfall sufficient
Apr 2.2" 2.5" 0" ✅ Rainfall sufficient
May 2.2" 0.7" 1.5" 🚿 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" 0.3" 1.9" 🚿 Regular watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 2.2" 2.5" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Glenn 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 ~1,200 GDD — county provides 4,272 GDD Excellent fit

Celosia Planting Timeline — Glenn County, CA

Celosia Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow February 13 Feb 13 – Mar 6
Bloom April 17 Apr 17 – Nov 6

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Direct Sow
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
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

267 days in Glenn County

Growing Tips for Celosia in Glenn County

Direct sow Celosia outdoors after March 06 in Glenn 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 Glenn County, CA?

Glenn County is in Zone 9b with an average last frost of March 6. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Glenn County, CA?

Glenn County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 6 and first fall frost is November 28.

When should I plant Celosia in Glenn County, CA?

In Glenn County, CA, plant Celosia after the last frost (around March 6) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Glenn County, CA for Celosia?

Glenn 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 Glenn County's climate?

Yes — Celosia grows well in Glenn County's temperate climate. Glenn County averages a 267-day frost-free season, with last frost around March 6 and first frost around November 28.

🌱

Your Glenn County Garden Planner — Free

A 22-page printable planner built for Glenn 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 Glenn County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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