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When to plant Celosia in Adams County, CO

Adams County's climate puts the Celosia spring window between May 11 and June 1. time plantings around the expected last-frost window for best survival.

When to Plant Celosia in Adams County, CO

Adams County, Colorado Zone 6a June

Your June gardening checklist

Each item below is timed to Adams County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 4
Avg. first frost October 5
Soil temp (4") 52°F
Watering High
Pest pressure High
Daylight 14.8 hrs
  1. Time to start celosia inside

    Label every cell. You will absolutely forget which is which otherwise.

Coming up in July — start thinking about
  • 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.

Adams County, Colorado is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.

At an elevation of 5,827 feet, Adams County receives approximately 23.9 inches of rainfall annually with predominantly 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
Adams County, CO (Zone 6a) Moderate season
154 days
Last Spring Frost May 4
154 growing days
First Fall Frost October 5

Adams County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 25 Transplant: May 6 🌸 Bloom: Jul 8 – Oct 21
Recommended (50%) ✗ May not fit
Start indoors: Mar 30 Transplant: May 11 🌸 Bloom: Jul 13 – Oct 26
Safe Start (90%) ✗ May not fit
Start indoors: Apr 16 Transplant: May 28 🌸 Bloom: Jul 30 – Nov 12

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 Adams County

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Celosia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Celosia.

How to Plant Celosia

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

Succession Planting Celosia

2
successive plantings in your 154-day season

Sow every 6.9 weeks. Last sowing by Jul 07 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 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 1.8" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.2" 2.5" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 2.1" 0.1" 💧 Light watering
Aug 2.2" 2.8" 0" ✅ Rainfall sufficient
Sep 2.2" 1.8" 0.4" 💧 Light watering
Oct 2.2" 2.3" 0" ✅ Rainfall sufficient
Nov 1.5" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Adams 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 2,348 GDD Excellent fit

Celosia Planting Timeline — Adams County, CO

Celosia Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 11 May 11 – Jun 1
Bloom July 13 Jul 13 – Oct 26

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Direct Sow
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: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

154 days in Adams County

Growing Tips for Celosia in Adams County

Direct sow Celosia outdoors after May 04 in Adams County when soil has warmed and frost danger has passed.

Adams County receives only 24" of rain annually. Celosia needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Adams County, CO?

Adams County is in Zone 6a with an average last frost of May 4. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, CO?

Adams County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 4 and first fall frost is October 5.

When should I plant Celosia in Adams County, CO?

In Adams County, CO, plant Celosia after the last frost (around May 4) and before the first frost (around October 5). Best results when soil holds above 50°F.

What growing zone is Adams County, CO for Celosia?

Adams County sits in USDA Zone 6a. Celosia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Celosia grow in Adams County's climate?

Yes — Celosia grows well in Adams County's temperate climate. Adams County averages a 154-day frost-free season, with last frost around May 4 and first frost around October 5.

🌱

Your Adams County Garden Planner — Free

A 22-page printable planner built for Adams County (Zone 6a). 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 Adams County, CO. 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.