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When to plant Vinca (Annual) in Perry County County,

Perry County County's short 194-day growing season means one Vinca (Annual) planting between April 9 and April 23. No fall crop in Zone 7a.

When to Plant Vinca (Annual) in Perry County, IL

Perry County, Illinois Zone 7a June

Perry County, Illinois gardeners: here's your June plan

Your garden in Perry County, Illinois is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 9
Avg. first frost October 20
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Sow vinca (annual) in trays indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Harvest vinca (annual) as they ripen

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

July prep starts now
  • First harvests: vinca (annual)

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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.

Perry County, Illinois is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 806 feet, Perry County receives approximately 36.9 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
Perry County, IL (Zone 7a) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20

Perry County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Jan 24 Transplant: Apr 4 🌸 Bloom: Jun 13 – Oct 3
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Jan 29 Transplant: Apr 9 🌸 Bloom: Jun 18 – Oct 8
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Feb 9 Transplant: Apr 20 🌸 Bloom: Jun 29 – Oct 19

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 Perry County

How your county's soil matches Vinca (Annual)'s growing requirements.

Soil pH

Your soil pH (6.1–7.0) is within Vinca (Annual)'s preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Perry County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) — Vinca (Annual) will thrive.

How to Plant Vinca (Annual)

0.1"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Vinca (Annual)

3
successive plantings in your 194-day season

Sow every 8 weeks. Last sowing by Jul 22 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Vinca (Annual)

Vinca (Annual) needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Vinca (Annual) Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 2.7" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Perry County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Vinca (Annual) 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.

Vinca (Annual) needs ~1,100 GDD — county provides 2,667 GDD Excellent fit

Vinca (Annual) Planting Timeline — Perry County, IL

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors April 9 Apr 9 – Apr 23
Bloom June 18 Jun 18 – Oct 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Perry County

Growing Tips for Vinca (Annual) in Perry County

Direct sow Vinca (Annual) outdoors after April 09 in Perry County when soil has warmed and frost danger has passed.

General growing tips

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 Perry County, IL?

Perry County is in Zone 7a with an average last frost of April 9. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Perry County, IL?

Perry County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 20.

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

In Perry County County, , plant Vinca (Annual) after the last frost (around April 9) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Perry County County, for Vinca (Annual)?

Perry County County sits in USDA Zone 7a. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.

Can Vinca (Annual) grow in Perry County County's climate?

Yes — Vinca (Annual) grows well in Perry County County's temperate climate. Perry County County averages a 194-day frost-free season, with last frost around April 9 and first frost around October 20.

🌱

Your Perry County Garden Planner — Free

A 22-page printable planner built for Perry County (Zone 7a). 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 Perry County, IL. 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.