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When to plant Impatiens in Delta County, CO

Delta County's short 160-day growing season means one Impatiens planting between May 8 and May 22. No fall crop in Zone 6b.

When to Plant Impatiens in Delta County, CO

Delta County, Colorado Zone 6b July

Top priorities for Delta County, Colorado gardeners in July

A quick July briefing for Delta County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 1
Avg. first frost October 8
Soil temp (4") 71°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Pick impatiens

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  • First harvests: impatiens

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Impatiens (Impatiens walleriana) are the go-to annual for shaded beds and containers. They produce a continuous carpet of flat-faced blooms from transplant until frost, needing little deadheading. Their preference for consistent moisture and part-shade makes them ideal under trees and along north-facing borders.

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 Impatiens during the growing season. With low rainfall, drip irrigation is essential for growing Impatiens successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly
Delta County, CO (Zone 6b) Moderate season
160 days
Last Spring Frost May 1
160 growing days
First Fall Frost October 8

Delta County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 25 Transplant: Apr 29 🌸 Bloom: Jul 8 – Oct 21
Recommended (50%) ✗ May not fit
Start indoors: Mar 6 Transplant: May 8 🌸 Bloom: Jul 17 – Oct 30
Safe Start (90%) ✗ May not fit
Start indoors: Mar 22 Transplant: May 24 🌸 Bloom: Aug 2 – Nov 15

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 Delta County

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

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Impatiens prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Impatiens.

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

3
successive plantings in your 160-day season

Sow every 6.9 weeks. Last sowing by Jul 25 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,108 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Impatiens

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

Month Impatiens Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 4.3" 1.4" 2.9" 🚿 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" 1.1" 3.2" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Impatiens 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.

Impatiens needs ~1,029 GDD — county provides 2,440 GDD Excellent fit

Impatiens Planting Timeline — Delta County, CO

Impatiens 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

· 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors
June
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

160 days in Delta County

Growing Tips for Impatiens in Delta County

Direct sow Impatiens outdoors after May 01 in Delta County when soil has warmed and frost danger has passed.

Delta County receives only 13" of rain annually. Impatiens 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 at 70–75°F; germination requires light — do not cover seeds. Transplant after last frost once nights consistently exceed 50°F. Water regularly — wilting causes bud drop and they rarely fully recover the same flush. Watch for impatiens downy mildew (IDM); consider New Guinea impatiens as a resistant alternative in affected regions. Pinch tips at planting to encourage branching.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Impatiens in Delta County, CO?

Delta County is in Zone 6b with an average last frost of May 1. Plan your Impatiens 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 Impatiens in Delta County, CO?

In Delta County, CO, plant Impatiens 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 Impatiens?

Delta County sits in USDA Zone 6b. Impatiens grows reliably in zones 2a through 11b, so it's a good fit here.

Can Impatiens grow in Delta County's climate?

Yes — Impatiens 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.

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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 Delta County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.