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When to plant Vinca (Annual) in Buchanan County, MO

Plant Vinca (Annual) in Buchanan County, between April 20 and May 4 — the only viable window. Zone 6a's short season (194 frost-free days) rules out a fall crop.

When to Plant Vinca (Annual) in Buchanan County, MO

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.

Buchanan County, Missouri is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.

At an elevation of 1,340 feet, Buchanan County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Vinca (Annual) to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Buchanan County, MO (Zone 6a) Moderate season
194 days
Last Spring Frost April 13
194 growing days
First Fall Frost October 24

Buchanan County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Vinca (Annual) Planting Timeline — Buchanan County, MO

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 20 Apr 20 – May 4
Bloom June 29 Jun 29 – Oct 5

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors
May Transplant Outdoors
June Bloom
July Bloom
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 6a

📆 Growing Season

194 days in Buchanan County

Growing Tips for Buchanan 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 Buchanan County, MO?

Buchanan County is in Zone 6a with an average last frost of April 13. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Buchanan County, MO?

Buchanan County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 24.

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

In Buchanan County, MO, plant Vinca (Annual) after the last frost (around April 13) and before the first frost (around October 24). Best results when soil holds above 50°F.

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

Buchanan County sits in USDA Zone 6a. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.

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

Yes — Vinca (Annual) grows well in Buchanan County's temperate climate. Buchanan County averages a 194-day frost-free season, with last frost around April 13 and first frost around October 24.

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Your Buchanan County Garden Planner — Free

A 22-page printable planner built for Buchanan 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.

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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 Buchanan County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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