When to plant Celosia in Jefferson County, ID
Plant Celosia in Jefferson County, between June 5 and June 26 — the only viable window. Zone 5a's short season (122 frost-free days) rules out a fall crop.
When to Plant Celosia in Jefferson County, ID
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.
Jefferson County, Idaho is in USDA Zone 5a. The average last spring frost is May 22 and the first fall frost is September 21, giving you a growing season of approximately 122 days.
At an elevation of 5,094 feet, Jefferson County receives approximately 18 inches of rainfall annually with predominantly loam soil. Summer highs average 87°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.
Jefferson County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Celosia Planting Timeline — Jefferson County, ID
Celosia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 17 | Apr 17 – May 1 |
| Transplant Outdoors | June 5 | Jun 5 – Jun 19 |
| Direct Sow | June 5 | Jun 5 – Jun 26 |
| Bloom | August 7 | Aug 7 – Nov 6 |
Plant 0.1" deep · 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5a
📆 Growing Season
122 days in Jefferson County
Growing Tips for Jefferson County
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 →
Celosia in Other Locations
Frequently Asked Questions
When should I plant Celosia in Jefferson County, ID?
Jefferson County is in Zone 5a with an average last frost of May 22. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, ID?
Jefferson County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 22 and first fall frost is September 21.
When should I plant Celosia in Jefferson County, ID?
In Jefferson County, ID, plant Celosia after the last frost (around May 22) and before the first frost (around September 21). Best results when soil holds above 50°F.
What growing zone is Jefferson County, ID for Celosia?
Jefferson County sits in USDA Zone 5a. Celosia grows reliably in zones 3a through 11b, so it's a good fit here.
Can Celosia grow in Jefferson County's climate?
Yes — Celosia grows well in Jefferson County's temperate climate. Jefferson County averages a 122-day frost-free season, with last frost around May 22 and first frost around September 21.
Your Jefferson County Garden Planner — Free
A 22-page printable planner built for Jefferson County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.