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When to Plant Impatiens in Robertson County, TX

Robertson County, Texas Zone 9a June

This month in Robertson County, Texas

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 7
Avg. first frost November 16
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Collect impatiens at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong July, finish these tasks
  • 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.

Robertson County, Texas is in USDA Zone 9a. The average last spring frost is March 7 and the first fall frost is November 16, giving you a growing season of approximately 254 days.

At an elevation of 85 feet, Robertson County receives approximately 61.1 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Impatiens during the growing season. Clay soil retains moisture well for Impatiens, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Impatiens root diseases.

Annual Blooms in Summer Pollinator-friendly
Robertson County, TX (Zone 9a) Long season
254 days
Last Spring Frost March 7
254 growing days
First Fall Frost November 16
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Robertson County Soil Profile

Soil Type

Clay

Soil pH

6.8-8

Drainage

Well Drained

Impatiens Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Jan 3 Transplant: Feb 14 🌸 Bloom: Apr 25 – Oct 10
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Jan 10 Transplant: Feb 21 🌸 Bloom: May 2 – Oct 17
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Feb 10 Transplant: Mar 24 🌸 Bloom: Jun 2 – Nov 17

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 Robertson County

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

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Impatiens prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (45% clay) in Robertson County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Impatiens.

How to Plant Impatiens

10"
Between Plants
12"
Between Rows

Succession Planting Impatiens

5
successive plantings in your 254-day season

Sow every 6.9 weeks. Last sowing by Sep 02 to harvest before frost.

Impatiens Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.4" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 5.6" 0" ✅ Rainfall sufficient
May 4.3" 10" 0" ✅ Rainfall sufficient
Jun 4.3" 8.4" 0" ✅ Rainfall sufficient
Jul 4.3" 8.3" 0" ✅ Rainfall sufficient
Aug 4.3" 8.2" 0" ✅ Rainfall sufficient
Sep 4.3" 5.2" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Robertson 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 ~1,333 GDD — county provides 5,016 GDD Excellent fit

Impatiens Planting Timeline — Robertson County, TX

Impatiens Planting Calendar

Activity When Date Range
Start Indoors January 10 Jan 10 – Jan 24
Transplant Outdoors February 21 Feb 21 – Mar 7
Bloom May 2 May 2 – Oct 17

· 10" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

254 days in Robertson County

Growing Tips for Impatiens in Robertson County

Direct sow Impatiens outdoors after March 07 in Robertson County when soil has warmed and frost danger has passed.

With Robertson County's clay soil (45% clay), work in 3-4 inches of compost before planting Impatiens. Avoid tilling when soil is wet to prevent compaction.

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 Robertson County, TX?

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

What planting zone is Robertson County, TX?

Robertson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 7 and first fall frost is November 16.

🌱

Your Robertson County Garden Planner — Free

A 22-page printable planner built for Robertson County (Zone 9a). 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 Robertson County, TX. 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.