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When to Plant Impatiens in Clark County, NV

Clark County, Nevada Zone 9b July

Clark County, Nevada gardeners: here's your July plan

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

Avg. last frost February 28
Avg. first frost November 23
Soil temp (4") 87°F
Watering High
Pest pressure High
Daylight 14.2 hrs
  1. Harvest impatiens as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to August
  • 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.

Clark County, Nevada is in USDA Zone 9b. The average last spring frost is February 28 and the first fall frost is November 23, giving you a growing season of approximately 268 days.

At an elevation of 2,811 feet, Clark County receives approximately 9.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 111°F, so Impatiens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Impatiens will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Impatiens successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly
Clark County, NV (Zone 9b) Long season
268 days
Last Spring Frost February 28
268 growing days
First Fall Frost November 23

Clark County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.4

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Dec 17 Transplant: Jan 21 🌸 Bloom: Apr 1 – Sep 30
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Jan 3 Transplant: Feb 7 🌸 Bloom: Apr 18 – Oct 17
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Feb 8 Transplant: Mar 15 🌸 Bloom: May 24 – Nov 22

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 Clark County

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

Soil pH

Your soil pH (7.3–8.4) is more alkaline than Impatiens prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Clark County warms quickly in spring but drains fast. Impatiens will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Impatiens.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Impatiens.

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

5
successive plantings in your 268-day season

Sow every 6.9 weeks. Last sowing by Sep 09 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 3,318 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 0.7" 0" ❄️ Dormant
Feb 4.3" 0.6" 3.7" 🚿 Regular watering
Mar 4.3" 0.6" 3.7" 🚿 Regular watering
Apr 4.3" 0.3" 4" 🚿 Regular watering
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 4.3" 0.9" 3.4" 🚿 Regular watering
Nov 4.3" 0.5" 3.8" 🚿 Regular watering
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Clark 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 ~2,244 GDD — county provides 8,944 GDD Excellent fit

Impatiens Planting Timeline — Clark County, NV

Impatiens Planting Calendar

Activity When Date Range
Start Indoors January 3 Jan 3 – Jan 17
Transplant Outdoors February 7 Feb 7 – Feb 21
Bloom April 18 Apr 18 – Oct 17

· 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
March
April Bloom
May Bloom
June Bloom
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 9b

📆 Growing Season

268 days in Clark County

Growing Tips for Impatiens in Clark County

Direct sow Impatiens outdoors after February 28 in Clark County when soil has warmed and frost danger has passed.

Sandy soil in Clark County dries quickly — mulch Impatiens with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 111°F in Clark County, provide afternoon shade for Impatiens and water deeply in the morning.

Clark County receives only 9" 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 Clark County, NV?

Clark County is in Zone 9b with an average last frost of February 28. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, NV?

Clark County, Nevada is in USDA Hardiness Zone 9b. The average last spring frost is February 28 and first fall frost is November 23.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 9b). 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 Clark County, NV. 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.