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When to plant Vinca (Annual) in Cheyenne County, KS

Cheyenne County's 158-day season only supports one Vinca (Annual) planting per year. Sow between May 11 and May 25 for the best chance at full maturity before October 9.

When to Plant Vinca (Annual) in Cheyenne County, KS

Cheyenne County, Kansas Zone 6a June

This month in Cheyenne County, Kansas

Each item below is timed to Cheyenne County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 4
Avg. first frost October 9
Soil temp (4") 68°F
Watering High
Pest pressure High
Daylight 14.8 hrs
Coming up in July — start thinking about
  • Starting indoors: vinca (annual)
  • 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.

Cheyenne County, Kansas is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 9, giving you a growing season of approximately 158 days.

At an elevation of 967 feet, Cheyenne County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Vinca (Annual) during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Cheyenne County, KS (Zone 6a) Moderate season
158 days
Last Spring Frost May 4
158 growing days
First Fall Frost October 9

Cheyenne County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 19 Transplant: May 7 🌸 Bloom: Jul 16 – Oct 22
Recommended (50%) ✗ May not fit
Start indoors: Feb 23 Transplant: May 11 🌸 Bloom: Jul 20 – Oct 26
Safe Start (90%) ✗ May not fit
Start indoors: Mar 12 Transplant: May 28 🌸 Bloom: Aug 6 – Nov 12

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 Cheyenne County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Vinca (Annual).

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Vinca (Annual).

How to Plant Vinca (Annual)

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

Succession Planting Vinca (Annual)

2
successive plantings in your 158-day season

Sow every 8 weeks. Last sowing by Jul 11 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Only during dry spells
Season total 7 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.2" 2.6" 0" ✅ Rainfall sufficient
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 2.4" 0" ✅ Rainfall sufficient
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.2" 2.3" 0" ✅ Rainfall sufficient
Nov 1.7" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Cheyenne 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 ~1,160 GDD — county provides 2,291 GDD Excellent fit

Vinca (Annual) Planting Timeline — Cheyenne County, KS

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors May 11 May 11 – May 25
Bloom July 20 Jul 20 – Oct 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

158 days in Cheyenne County

Growing Tips for Vinca (Annual) in Cheyenne County

Direct sow Vinca (Annual) outdoors after May 04 in Cheyenne County when soil has warmed and frost danger has passed.

Cheyenne County receives only 24" of rain annually. Vinca (Annual) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Cheyenne County, KS?

Cheyenne County is in Zone 6a with an average last frost of May 4. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cheyenne County, KS?

Cheyenne County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is May 4 and first fall frost is October 9.

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

In Cheyenne County, KS, plant Vinca (Annual) after the last frost (around May 4) and before the first frost (around October 9). Best results when soil holds above 50°F.

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

Cheyenne 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 Cheyenne County's climate?

Yes — Vinca (Annual) grows well in Cheyenne County's temperate climate. Cheyenne County averages a 158-day frost-free season, with last frost around May 4 and first frost around October 9.

🌱

Your Cheyenne County Garden Planner — Free

A 22-page printable planner built for Cheyenne 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 Cheyenne County, KS. 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.