Blog

When to plant Impatiens in Gem County, ID

In Gem County, Impatiens is a single-season spring crop — there's no second fall window. Plant May 16–May 30 for an 60–75-day harvest, finishing well before the October 1 first frost.

When to Plant Impatiens in Gem County, ID

Gem County, Idaho Zone 7a June

Your June gardening checklist

Here's what deserves your attention in Gem County, Idaho this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost May 9
Avg. first frost October 1
Soil temp (4") 56°F
Watering Critical
Pest pressure High
Daylight 15.3 hrs
Looking ahead to July
  • Starting indoors: impatiens
  • First harvests: impatiens

Instant PDF download. No spam, unsubscribe any time.

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.

Gem County, Idaho is in USDA Zone 7a. The average last spring frost is May 9 and the first fall frost is October 1, giving you a growing season of approximately 145 days.

At an elevation of 6,100 feet, Gem County receives approximately 16 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
Gem County, ID (Zone 7a) Short season
145 days
Last Spring Frost May 9
145 growing days
First Fall Frost October 1

Gem County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 6 Transplant: May 8 🌸 Bloom: Jul 17 – Nov 6
Recommended (50%) ✗ May not fit
Start indoors: Mar 14 Transplant: May 16 🌸 Bloom: Jul 25 – Nov 14
Safe Start (90%) ✗ May not fit
Start indoors: Apr 12 Transplant: Jun 14 🌸 Bloom: Aug 23 – Dec 13

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 Gem County

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

Soil pH

Your soil pH (6.7–7.7) is more alkaline than Impatiens prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Impatiens.

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

2
successive plantings in your 145-day season

Sow every 6.9 weeks. Last sowing by Jul 18 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 831 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.2" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 4.3" 1.7" 2.6" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.5" 2.8" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 4.3" 1.5" 2.8" 🚿 Regular watering
Nov 1.1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Gem 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 2,211 GDD Excellent fit

Impatiens Planting Timeline — Gem County, ID

Impatiens Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors May 16 May 16 – May 30
Bloom July 25 Jul 25 – Nov 14

· 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 Bloom
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

145 days in Gem County

Growing Tips for Impatiens in Gem County

Direct sow Impatiens outdoors after May 09 in Gem County when soil has warmed and frost danger has passed.

Gem County receives only 16" 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 Gem County, ID?

Gem County is in Zone 7a with an average last frost of May 9. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gem County, ID?

Gem County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 9 and first fall frost is October 1.

When should I plant Impatiens in Gem County, ID?

In Gem County, ID, plant Impatiens after the last frost (around May 9) and before the first frost (around October 1). Best results when soil holds above 50°F.

What growing zone is Gem County, ID for Impatiens?

Gem County sits in USDA Zone 7a. Impatiens grows reliably in zones 2a through 11b, so it's a good fit here.

Can Impatiens grow in Gem County's climate?

Yes — Impatiens grows well in Gem County's temperate climate. Gem County averages a 145-day frost-free season, with last frost around May 9 and first frost around October 1.

🌱

Your Gem County Garden Planner — Free

A 22-page printable planner built for Gem County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Gem County, ID. Local conditions may vary. Last updated: June 2026.

Sources & credits

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