When to Plant Impatiens in Centre County, PA
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.
Centre County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 26 and the first fall frost is October 24, giving you a growing season of approximately 181 days.
At an elevation of 1,105 feet, Centre County receives approximately 45.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Impatiens during the growing season.
Centre County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Impatiens Planting Timeline — Centre County, PA
Impatiens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Bloom | July 12 | Jul 12 – Oct 25 |
· 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
Moderate — regular watering
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–6.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
181 days in Centre County
Growing Tips for Centre County
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 Centre County, PA?
Centre County is in Zone 6b with an average last frost of April 26. Plan your Impatiens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Centre County, PA?
Centre County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 26 and first fall frost is October 24.
Your Centre County Garden Planner — Free
A 22-page printable planner built for Centre 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.