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When to plant Phlox in Kit Carson County, CO

Kit Carson County gardeners should plant Phlox between May 16 and June 6 in spring. With Kit Carson County's Zone 6a climate (last frost May 9), Phlox needs 80–110 days to mature — plant by June 20 for a full harvest.

When to Plant Phlox in Kit Carson County, CO

Kit Carson County, Colorado Zone 6a July

Your July gardening checklist

Your garden in Kit Carson County, Colorado is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost May 9
Avg. first frost October 8
Soil temp (4") 60°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Fire up the seed-starting tray: phlox

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

  2. Harvest phlox as they ripen

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of August
  • First harvests: phlox

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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.

Kit Carson County, Colorado is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 8, giving you a growing season of approximately 152 days.

At an elevation of 6,382 feet, Kit Carson County receives approximately 23.2 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Phlox during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Kit Carson County, CO (Zone 6a) Moderate season
152 days
Last Spring Frost May 9
152 growing days
First Fall Frost October 8

Kit Carson County Soil Profile

Soil Type

Loam

Soil pH

6.4-8

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 27 Transplant: May 8 🌸 Bloom: Jul 17 – Oct 9
Recommended (50%) ✗ May not fit
Start indoors: Mar 7 Transplant: May 16 🌸 Bloom: Jul 25 – Oct 17
Safe Start (90%) ✗ May not fit
Start indoors: Mar 18 Transplant: May 27 🌸 Bloom: Aug 5 – Oct 28

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 Kit Carson County

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

Soil pH

Your soil pH (6.4–8.0) is more alkaline than Phlox prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Kit Carson County is excellent for Phlox — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Phlox

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Phlox

2
successive plantings in your 152-day season

Sow every 9.1 weeks. Last sowing by Jun 20 to harvest before frost.

Phlox Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 583 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 2.2" 2.1" 💧 Light watering
Aug 4.3" 2.7" 1.6" 💧 Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Phlox 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.

Phlox needs ~1,306 GDD — county provides 2,090 GDD Excellent fit

Phlox Planting Timeline — Kit Carson County, CO

Phlox Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 16 May 16 – Jun 6
Bloom July 25 Jul 25 – Oct 17

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
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

1"/week · 1-2 times/week

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

152 days in Kit Carson County

Growing Tips for Phlox in Kit Carson County

Direct sow Phlox outdoors after May 09 in Kit Carson County when soil has warmed and frost danger has passed.

Kit Carson County receives only 23" of rain annually. Phlox needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Kit Carson County, CO?

Kit Carson County is in Zone 6a with an average last frost of May 9. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kit Carson County, CO?

Kit Carson County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 8.

When should I plant Phlox in Kit Carson County, CO?

In Kit Carson County, CO, plant Phlox after the last frost (around May 9) and before the first frost (around October 8). Best results when soil holds above 50°F.

What growing zone is Kit Carson County, CO for Phlox?

Kit Carson 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 Kit Carson County's climate?

Yes — Phlox grows well in Kit Carson County's temperate climate. Kit Carson County averages a 152-day frost-free season, with last frost around May 9 and first frost around October 8.

🌱

Your Kit Carson County Garden Planner — Free

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

Sources & credits

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