When to plant Impatiens in Cook County County,
In Cook County County, Impatiens is a spring-only crop. Plant April 30–May 14 once soil hits 50°F.
When to Plant Impatiens in Cook County, IL
Cook County, Illinois gardeners: here's your June plan
A quick June briefing for Cook County, Illinois gardeners — what's urgent, what's next, and what can wait.
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Indoor seed-starting week for impatiens
Your window is short. These crops want several weeks of indoor growth before they go outside.
July will be here before you know it — start on
- First harvests: impatiens
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.
Cook County, Illinois is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.
At an elevation of 728 feet, Cook County receives approximately 35.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Impatiens during the growing season.
Cook County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
Drainage
Well Drained
Impatiens Planting Risk Windows
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 Cook County
How your county's soil matches Impatiens's growing requirements.
Soil pH
Your soil pH (6.0–7.0) overlaps with Impatiens's range (6.0–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Cook County is excellent for Impatiens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Impatiens will thrive.
How to Plant Impatiens
Succession Planting Impatiens
Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.
Impatiens Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Cook 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 Planting Timeline — Cook County, IL
Impatiens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Bloom | July 9 | Jul 9 – Oct 15 |
· 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors |
| 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 · Only during dry spells
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
177 days in Cook County
Growing Tips for Impatiens in Cook County
Direct sow Impatiens outdoors after April 23 in Cook County when soil has warmed and frost danger has passed.
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 →
Impatiens in Other Locations
Frequently Asked Questions
When should I plant Impatiens in Cook County, IL?
Cook County is in Zone 6a with an average last frost of April 23. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cook County, IL?
Cook County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 17.
When should I plant Impatiens in Cook County County, ?
In Cook County County, , plant Impatiens after the last frost (around April 23) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Cook County County, for Impatiens?
Cook County County sits in USDA Zone 6a. Impatiens grows reliably in zones 2a through 11b, so it's a good fit here.
Can Impatiens grow in Cook County County's climate?
Yes — Impatiens grows well in Cook County County's temperate climate. Cook County County averages a 177-day frost-free season, with last frost around April 23 and first frost around October 17.
Your Cook County Garden Planner — Free
A 22-page printable planner built for Cook 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.