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When to plant Celosia in Isleton, CA

Isleton gardeners should plant Celosia between January 22 and February 12 in spring. With Isleton's Zone 9b climate (last frost February 12), Celosia needs 60–90 days to mature — plant by September 2 for a full harvest.

When to Plant Celosia in Isleton, CA

Sacramento County, California Zone 9b July

Your July game plan for Sacramento County, California

Welcome to July in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 12
Avg. first frost December 1
Soil temp (4") 92°F
Watering Critical
Pest pressure High
Daylight 14.4 hrs
  1. Basket week: celosia

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

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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.

Isleton, California is in USDA Zone 9b. The average last spring frost is February 12 and the first fall frost is December 1, giving you a growing season of approximately 292 days.

At an elevation of 263 feet, Sacramento County receives approximately 33.2 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Celosia during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Isleton, CA (Zone 9b) Year-round
292 days
Last Spring Frost February 12
292 growing days
First Fall Frost December 1

Isleton Soil Profile

Soil Type

Loam

Soil pH

6.4-7.1

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Start indoors: Dec 29 Transplant: Jan 5 🌸 Bloom: Mar 9 – Sep 28
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Jan 15 Transplant: Jan 22 🌸 Bloom: Mar 26 – Oct 15
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Mar 9 Transplant: Mar 16 🌸 Bloom: May 18 – Dec 7

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 Isleton

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

Soil pH

Your soil pH (6.4–7.1) overlaps with Celosia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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 292-day season

Sow every 6.9 weeks. Last sowing by Sep 02 to harvest before frost.

Celosia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 75 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 6.1" 0" ❄️ Dormant
Feb 2.2" 7.5" 0" ✅ Rainfall sufficient
Mar 2.2" 5.7" 0" ✅ Rainfall sufficient
Apr 2.2" 2.5" 0" ✅ Rainfall sufficient
May 2.2" 0.8" 1.4" 🚿 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" 0.3" 1.9" 🚿 Regular watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 2.2" 2.7" 0" ✅ Rainfall sufficient
Dec 2.2" 5.9" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Sacramento 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 ~1,312 GDD — county provides 5,127 GDD Excellent fit

Celosia Planting Timeline — Isleton, CA

Celosia Planting Calendar

Activity When Date Range
Start Indoors January 15 Jan 15 – Jan 29
Transplant Outdoors January 22 Jan 22 – Feb 5
Direct Sow January 22 Jan 22 – Feb 12
Bloom March 26 Mar 26 – Oct 15

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: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

292 days in Sacramento County

Growing Tips for Celosia in Isleton

Direct sow Celosia outdoors after February 12 in Sacramento 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 →

When should I plant Celosia in Isleton, CA?

In Isleton, CA, plant Celosia after the last frost (around February 12) and before the first frost (around December 1). Best results when soil holds above 50°F.

What growing zone is Isleton, CA for Celosia?

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

Can Celosia grow in Isleton's climate?

Yes — Celosia grows well in Isleton's temperate climate. Isleton averages a 293-day frost-free season, with last frost around February 12 and first frost around December 1.

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