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When to Plant Vinca (Annual) in Latimer County, OK

Latimer County, Oklahoma Zone 7b June

Top priorities for Latimer County, Oklahoma gardeners in June

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 5
Avg. first frost October 31
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Time to start vinca (annual) inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Collect vinca (annual) at their peak

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

Looking ahead to July
  • 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.

Latimer County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is October 31, giving you a growing season of approximately 209 days.

At an elevation of 773 feet, Latimer County receives approximately 33.6 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Vinca (Annual) during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Latimer County, OK (Zone 7b) Long season
209 days
Last Spring Frost April 5
209 growing days
First Fall Frost October 31

Latimer County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Jan 14 Transplant: Mar 25 🌸 Bloom: Jun 3 – Oct 7
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Jan 25 Transplant: Apr 5 🌸 Bloom: Jun 14 – Oct 18
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Feb 11 Transplant: Apr 22 🌸 Bloom: Jul 1 – Nov 4

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 Latimer County

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

Soil pH

Your soil pH (6.5–7.2) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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 209-day season

Sow every 8 weeks. Last sowing by Aug 02 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 5.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.7" 0" ✅ Rainfall sufficient
Jul 2.2" 4.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.2" 0" ✅ Rainfall sufficient
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Latimer 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 ~1,340 GDD — county provides 3,500 GDD Excellent fit

Vinca (Annual) Planting Timeline — Latimer County, OK

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 – Feb 8
Transplant Outdoors April 5 Apr 5 – Apr 19
Bloom June 14 Jun 14 – Oct 18

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: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

209 days in Latimer County

Growing Tips for Vinca (Annual) in Latimer County

Direct sow Vinca (Annual) outdoors after April 05 in Latimer 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 Latimer County, OK?

Latimer County is in Zone 7b with an average last frost of April 5. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Latimer County, OK?

Latimer County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is October 31.

🌱

Your Latimer County Garden Planner — Free

A 22-page printable planner built for Latimer County (Zone 7b). 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 Latimer County, OK. 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.