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When to Plant Vinca (Annual) in Elk County, PA

Annual vinca (Catharanthus roseus), also called Madagascar periwinkle, is one of the most heat- and drought-tolerant bedding plants available. Glossy foliage stays attractive all season while cheerful pinwheel blooms continue without deadheading. A top performer in hot, humid Southern summers where impatiens and begonias struggle. Self-cleaning; requires little maintenance once established.

Elk County, Pennsylvania is in USDA Zone 5b. The average last spring frost is May 17 and the first fall frost is October 9, giving you a growing season of approximately 145 days.

At an elevation of 59 feet, Elk County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Vinca (Annual) during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Elk County, PA (Zone 5b) Short season
145 days
Last Spring Frost May 17
145 growing days
First Fall Frost October 9

Elk County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Vinca (Annual) Planting Timeline — Elk County, PA

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 24 May 24 – Jun 7
Bloom August 2 Aug 2 – Oct 25

Plant 0.1" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

145 days in Elk County

Growing Tips for Elk County

Start seeds indoors 10–12 weeks before last frost — germination requires warm soil (75–80°F) and darkness. Do not cover seeds deeply; they need just a light dusting. Direct sowing is rarely practiced due to slow seedling establishment. Transplant after soil warms and frost danger has passed. Excellent drought tolerance once established; avoid overwatering. Performs best in well-drained beds or containers in full sun.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Vinca (Annual) in Elk County, PA?

Elk County is in Zone 5b with an average last frost of May 17. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Elk County, PA?

Elk County, Pennsylvania is in USDA Hardiness Zone 5b. The average last spring frost is May 17 and first fall frost is October 9.

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Your Elk County Garden Planner — Free

A 22-page printable planner built for Elk County (Zone 5b). 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 Elk County, PA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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