When to plant Petunia in Delta County, CO
In Delta County, Petunia is a single-season spring crop — there's no second fall window. Plant May 8–May 22 for an 70–90-day harvest, finishing well before the October 8 first frost.
When to Plant Petunia in Delta County, CO
Petunias (Petunia x hybrida) are warm-season tender annuals prized for their prolific, trumpet-shaped blooms in nearly every color. They perform from hanging baskets to garden borders and bloom continuously from late spring until frost, provided spent flowers are removed regularly.
Delta County, Colorado is in USDA Zone 6b. The average last spring frost is May 1 and the first fall frost is October 8, giving you a growing season of approximately 160 days.
At an elevation of 4,470 feet, Delta County receives approximately 13.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Petunia during the growing season. With low rainfall, drip irrigation is essential for growing Petunia successfully. Mulch heavily to conserve soil moisture.
Delta County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Petunia Planting Timeline — Delta County, CO
Petunia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Bloom | July 17 | Jul 17 – Oct 30 |
· 12" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
160 days in Delta County
Growing Tips for Delta County
Start seeds indoors 8–10 weeks before last frost; seeds need light to germinate — press onto moist mix surface, do not cover. Transplant after last frost once nights stay above 50°F. Pinch back leggy plants mid-summer to encourage bushy re-bloom. Wave/spreading types tolerate light shade but bloom less. Feed every 2 weeks with balanced fertilizer once established.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Petunia in Other Locations
Frequently Asked Questions
When should I plant Petunia in Delta County, CO?
Delta County is in Zone 6b with an average last frost of May 1. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Delta County, CO?
Delta County, Colorado is in USDA Hardiness Zone 6b. The average last spring frost is May 1 and first fall frost is October 8.
When should I plant Petunia in Delta County, CO?
In Delta County, CO, plant Petunia after the last frost (around May 1) and before the first frost (around October 8). Best results when soil holds above 50°F.
What growing zone is Delta County, CO for Petunia?
Delta County sits in USDA Zone 6b. Petunia grows reliably in zones 2a through 11b, so it's a good fit here.
Can Petunia grow in Delta County's climate?
Yes — Petunia grows well in Delta County's temperate climate. Delta County averages a 160-day frost-free season, with last frost around May 1 and first frost around October 8.
Your Delta County Garden Planner — Free
A 22-page printable planner built for Delta County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.