Blog

When to plant Celosia in Randolph County County,

In Zone 7a (Randolph County County), direct-sow Celosia between April 11 and May 2 for spring, after the April 11 last-frost mark.

When to Plant Celosia in Randolph County, IL

Randolph County, Illinois Zone 7a June

June to-do list for Randolph County, Illinois

June is a pivotal month for Randolph County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 11
Avg. first frost October 20
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Pick celosia

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

Coming up in July — start thinking about
  • First harvests: celosia

Instant PDF download. No spam, unsubscribe any time.

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.

Randolph County, Illinois is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 20, giving you a growing season of approximately 192 days.

At an elevation of 501 feet, Randolph County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Celosia during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Randolph County, IL (Zone 7a) Moderate season
192 days
Last Spring Frost April 11
192 growing days
First Fall Frost October 20

Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Mar 8 Transplant: Apr 5 🌸 Bloom: Jun 7 – Oct 4
Recommended (50%) ✓ Fits season (10 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🌸 Bloom: Jun 13 – Oct 10
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🌸 Bloom: Jun 25 – Oct 22

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 Randolph County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Celosia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — 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 192-day season

Sow every 6.9 weeks. Last sowing by Jul 22 to harvest before frost.

Celosia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 1.2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.3" 0" ✅ Rainfall sufficient
Jul 2.2" 3.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Randolph 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 ~1,088 GDD — county provides 2,784 GDD Excellent fit

Celosia Planting Timeline — Randolph County, IL

Celosia Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow April 11 Apr 11 – May 2
Bloom June 13 Jun 13 – Oct 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Direct Sow
June Bloom
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 7a

📆 Growing Season

192 days in Randolph County

Growing Tips for Celosia in Randolph County

Direct sow Celosia outdoors after April 11 in Randolph 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 Randolph County, IL?

Randolph County is in Zone 7a with an average last frost of April 11. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, IL?

Randolph County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 20.

When should I plant Celosia in Randolph County County, ?

In Randolph County County, , plant Celosia after the last frost (around April 11) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Randolph County County, for Celosia?

Randolph County County sits in USDA Zone 7a. Celosia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Celosia grow in Randolph County County's climate?

Yes — Celosia grows well in Randolph County County's temperate climate. Randolph County County averages a 192-day frost-free season, with last frost around April 11 and first frost around October 20.

🌱

Your Randolph County Garden Planner — Free

A 22-page printable planner built for Randolph County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Randolph County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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