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When to plant Celosia in Ada County County,

For Ada County County, gardeners: plant Celosia April 23 through May 14 once soil reads 50°F.

When to Plant Celosia in Ada County, ID

Ada County, Idaho Zone 7a June

June in the garden — Ada County, Idaho

We've pulled the most time-sensitive tasks for Ada County, Idaho this June and put them front and centre. Tackle them in order.

Avg. last frost April 23
Avg. first frost October 16
Soil temp (4") 61°F
Watering High
Pest pressure High
Daylight 15.2 hrs
  1. Pick celosia

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July will be here before you know it — start on
  • 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.

Ada County, Idaho is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.

At an elevation of 4,372 feet, Ada County receives approximately 19.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Celosia during the growing season. With low rainfall, drip irrigation is essential for growing Celosia successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Ada County, ID (Zone 7a) Moderate season
176 days
Last Spring Frost April 23
176 growing days
First Fall Frost October 16
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Ada County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 18 Transplant: Apr 15 🌸 Bloom: Jun 17 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Mar 26 Transplant: Apr 23 🌸 Bloom: Jun 25 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: Apr 15 Transplant: May 13 🌸 Bloom: Jul 15 – Nov 11

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 Ada County

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

Soil pH

Your soil pH (6.4–7.7) is more alkaline than Celosia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Celosia.

How to Plant Celosia

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

Succession Planting Celosia

3
successive plantings in your 176-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
0.5″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 52 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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.2" 2" 0.2" 💧 Light watering
May 2.2" 2.4" 0" ✅ Rainfall sufficient
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 2.4" 0" ✅ Rainfall sufficient
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.2" 1.8" 0.4" 💧 Light watering
Nov 1.3" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ada 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 3,080 GDD Excellent fit

Celosia Planting Timeline — Ada County, ID

Celosia Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 23 Apr 23 – May 14
Bloom June 25 Jun 25 – Oct 22

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 Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December
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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 7a

📆 Growing Season

176 days in Ada County

Growing Tips for Celosia in Ada County

Direct sow Celosia outdoors after April 23 in Ada County when soil has warmed and frost danger has passed.

Ada County receives only 20" 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 Ada County, ID?

Ada County is in Zone 7a with an average last frost of April 23. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ada County, ID?

Ada County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 16.

When should I plant Celosia in Ada County County, ?

In Ada County County, , plant Celosia after the last frost (around April 23) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Ada County County, for Celosia?

Ada 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 Ada County County's climate?

Yes — Celosia grows well in Ada County County's temperate climate. Ada County County averages a 176-day frost-free season, with last frost around April 23 and first frost around October 16.

🌱

Your Ada County Garden Planner — Free

A 22-page printable planner built for Ada 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.

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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 Ada County, ID. 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.