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When to plant Celosia in DeKalb County, IL

Spring Celosia in DeKalb County goes in April 29–May 20, once nighttime temps stop dipping near freezing.

When to Plant Celosia in DeKalb County, IL

DeKalb County, Illinois Zone 5b August

Your August planting checklist for DeKalb County, Illinois

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

Avg. last frost April 22
Avg. first frost October 16
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Basket week: celosia

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Get ahead of September
  • 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.

DeKalb County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 16, giving you a growing season of approximately 177 days.

At an elevation of 1,332 feet, DeKalb County receives approximately 34.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Celosia during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
DeKalb County, IL (Zone 5b) Moderate season
177 days
Last Spring Frost April 22
177 growing days
First Fall Frost October 16

DeKalb County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Mar 12 Transplant: Apr 23 🌸 Bloom: Jun 25 – Oct 1
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jul 1 – Oct 7
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: Apr 4 Transplant: May 16 🌸 Bloom: Jul 18 – Oct 24

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 DeKalb County

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Celosia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Celosia.

Organic Matter

Organic matter is excellent (5.1%) — Celosia will thrive.

How to Plant Celosia

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

Succession Planting Celosia

3
successive plantings in your 177-day season

Sow every 6.9 weeks. Last sowing by Jul 18 to harvest before frost.

Celosia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2.6" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in DeKalb 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 ~1,144 GDD — county provides 2,699 GDD Excellent fit

Celosia Planting Timeline — DeKalb County, IL

Celosia Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 29 Apr 29 – May 20
Bloom July 1 Jul 1 – Oct 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

177 days in DeKalb County

Growing Tips for Celosia in DeKalb County

Direct sow Celosia outdoors after April 22 in DeKalb 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 DeKalb County, IL?

DeKalb County is in Zone 5b with an average last frost of April 22. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is DeKalb County, IL?

DeKalb County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 16.

When should I plant Celosia in DeKalb County, IL?

In DeKalb County, IL, plant Celosia after the last frost (around April 22) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is DeKalb County, IL for Celosia?

DeKalb County sits in USDA Zone 5b. Celosia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Celosia grow in DeKalb County's climate?

Yes — Celosia grows well in DeKalb County's temperate climate. DeKalb County averages a 177-day frost-free season, with last frost around April 22 and first frost around October 16.

🌱

Your DeKalb County Garden Planner — Free

A 22-page printable planner built for DeKalb County (Zone 5b). 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 DeKalb County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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