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When to plant Phlox in Bent County, CO

In Bent County, plant Phlox in spring between May 6 and May 27, once soil temps hold above 50°F. Bent County's last frost averages April 29, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 80–110 days before the first frost on October 9.

When to Plant Phlox in Bent County, CO

Garden Phlox (Phlox paniculata) is a beloved native perennial of eastern North America, producing large, domed clusters of fragrant flowers atop upright stems from mid-summer into fall. Its sweet honey-like fragrance carries on summer evenings and draws hummingbirds, butterflies, and sphinx moths. Modern cultivars offer colors spanning white, pink, salmon, red, purple, and bicolors. A classic cottage garden stalwart, phlox combines well with black-eyed Susans, echinacea, and ornamental grasses in naturalistic plantings. Select mildew-resistant cultivars for best long-term performance.

Bent County, Colorado is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 9, giving you a growing season of approximately 163 days.

At an elevation of 4,516 feet, Bent County receives approximately 12.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Phlox during the growing season. With low rainfall, drip irrigation is essential for growing Phlox successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Bent County, CO (Zone 6a) Moderate season
163 days
Last Spring Frost April 29
163 growing days
First Fall Frost October 9

Bent County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Monthly Watering Guide for Phlox

Phlox needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Phlox Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 4.3" 1.4" 2.9" 🚿 Regular watering
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 1" 3.3" 🚿 Regular watering
Aug 4.3" 1.4" 2.9" 🚿 Regular watering
Sep 4.3" 1" 3.3" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Bent County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Phlox Planting Timeline — Bent County, CO

Phlox Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors May 6 May 6 – May 20
Direct Sow May 6 May 6 – May 27
Bloom July 15 Jul 15 – Oct 7

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

163 days in Bent County

Growing Tips for Bent County

Start seeds indoors 8–10 weeks before last frost, or transplant container divisions in spring. Named cultivar seeds may not come true; divisions from named plants are the preferred propagation method. Space generously (18–24 inches) and avoid overhead watering to reduce powdery mildew risk. Good air circulation is critical — thin clumps to the strongest 5–7 stems per plant in spring. Deadhead after the primary bloom flush to encourage secondary flowering. Division every 2–3 years in spring keeps plants vigorous. Fall planting of divisions (Zones 5+) is equally effective. Year 2+ plants develop into full clumps with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Phlox in Bent County, CO?

Bent County is in Zone 6a with an average last frost of April 29. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bent County, CO?

Bent County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is April 29 and first fall frost is October 9.

When should I plant Phlox in Bent County, CO?

In Bent County, CO, plant Phlox after the last frost (around April 29) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Bent County, CO for Phlox?

Bent County sits in USDA Zone 6a. Phlox grows reliably in zones 3a through 9a, so it's a good fit here.

Can Phlox grow in Bent County's climate?

Yes — Phlox grows well in Bent County's temperate climate. Bent County averages a 163-day frost-free season, with last frost around April 29 and first frost around October 9.

🌱

Your Bent County Garden Planner — Free

A 22-page printable planner built for Bent 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 Bent County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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