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

Plant Vinca (Annual) in Labette County, between April 7 and April 21 — the only viable window. Zone 7a's short season (203 frost-free days) rules out a fall crop.

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

Labette County, Kansas Zone 7a August

This month in Labette County, Kansas

Welcome to August in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 7
Avg. first frost October 27
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 13.4 hrs
  1. Bring in the vinca (annual)

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in September — start thinking about
  • 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.

Labette County, Kansas is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 27, giving you a growing season of approximately 203 days.

At an elevation of 421 feet, Labette County receives approximately 22.5 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Vinca (Annual) during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Labette County, KS (Zone 7a) Long season
203 days
Last Spring Frost April 7
203 growing days
First Fall Frost October 27

Labette County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Jan 21 Transplant: Apr 1 🌸 Bloom: Jun 10 – Sep 30
Recommended (50%) ✓ Fits season (21 days to spare)
Start indoors: Jan 27 Transplant: Apr 7 🌸 Bloom: Jun 16 – Oct 6
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Feb 10 Transplant: Apr 21 🌸 Bloom: Jun 30 – Oct 20

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 Labette County

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

Soil pH

Your soil pH (6.7–7.3) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

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)

3
successive plantings in your 203-day season

Sow every 8 weeks. Last sowing by Jul 29 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 75 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 3" 0" ✅ Rainfall sufficient
Jun 2.2" 4" 0" ✅ Rainfall sufficient
Jul 2.2" 2.8" 0" ✅ Rainfall sufficient
Aug 2.2" 2.4" 0" ✅ Rainfall sufficient
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.2" 1.6" 0.6" 💧 Light watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Labette 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 ~1,400 GDD — county provides 3,552 GDD Excellent fit

Vinca (Annual) Planting Timeline — Labette County, KS

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors April 7 Apr 7 – Apr 21
Bloom June 16 Jun 16 – Oct 6

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 · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

203 days in Labette County

Growing Tips for Vinca (Annual) in Labette County

Direct sow Vinca (Annual) outdoors after April 07 in Labette County when soil has warmed and frost danger has passed.

Labette County receives only 22" 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 Labette County, KS?

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

What planting zone is Labette County, KS?

Labette County, Kansas is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 27.

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

In Labette County, KS, plant Vinca (Annual) after the last frost (around April 7) and before the first frost (around October 27). Best results when soil holds above 50°F.

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

Labette 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 Labette County's climate?

Yes — Vinca (Annual) grows well in Labette County's temperate climate. Labette County averages a 203-day frost-free season, with last frost around April 7 and first frost around October 27.

🌱

Your Labette County Garden Planner — Free

A 22-page printable planner built for Labette 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 Labette County, KS. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.