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When to Plant Vinca (Annual) in Andrews County, TX

Andrews County, Texas Zone 8a June

Top priorities for Andrews County, Texas gardeners in June

Your Andrews County, Texas garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost March 29
Avg. first frost November 7
Soil temp (4") 76°F
Watering High
Pest pressure High
Daylight 14.1 hrs
  1. Begin indoor sowing: vinca (annual)

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

  2. It's harvest week for vinca (annual)

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

July will be here before you know it — start on
  • 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.

Andrews County, Texas is in USDA Zone 8a. The average last spring frost is March 29 and the first fall frost is November 7, giving you a growing season of approximately 223 days.

At an elevation of 1,776 feet, Andrews County receives approximately 52.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 100°F, so Vinca (Annual) may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Vinca (Annual) will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Andrews County, TX (Zone 8a) Long season
223 days
Last Spring Frost March 29
223 growing days
First Fall Frost November 7
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Andrews County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.5-8.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (24 days to spare)
Start indoors: Jan 8 Transplant: Mar 12 🌸 Bloom: May 21 – Oct 8
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Jan 18 Transplant: Mar 22 🌸 Bloom: May 31 – Oct 18
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🌸 Bloom: Jun 20 – Nov 7

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 Andrews County

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

Soil pH

Your soil pH (7.5–8.2) is more alkaline than Vinca (Annual) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Andrews County warms quickly in spring but drains fast. Vinca (Annual) will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.1%). Add 2-3 inches of compost before planting 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 223-day season

Sow every 8 weeks. Last sowing by Aug 09 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 3.6" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.2" 3.2" 0" ✅ Rainfall sufficient
Apr 2.2" 1.8" 0.4" 💧 Light watering
May 2.2" 1.2" 1" 💧 Light watering
Jun 2.2" 1.8" 0.4" 💧 Light watering
Jul 2.2" 8.7" 0" ✅ Rainfall sufficient
Aug 2.2" 9.8" 0" ✅ Rainfall sufficient
Sep 2.2" 6.9" 0" ✅ Rainfall sufficient
Oct 2.2" 5.4" 0" ✅ Rainfall sufficient
Nov 2.2" 2.9" 0" ✅ Rainfall sufficient
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Andrews 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 ~2,000 GDD — county provides 5,575 GDD Excellent fit

Vinca (Annual) Planting Timeline — Andrews County, TX

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 18 Jan 18 – Feb 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Bloom May 31 May 31 – Oct 18

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

223 days in Andrews County

Growing Tips for Vinca (Annual) in Andrews County

Direct sow Vinca (Annual) outdoors after March 29 in Andrews County when soil has warmed and frost danger has passed.

Sandy soil in Andrews County dries quickly — mulch Vinca (Annual) with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 100°F in Andrews County, provide afternoon shade for Vinca (Annual) and water deeply in the morning.

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 Andrews County, TX?

Andrews County is in Zone 8a with an average last frost of March 29. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Andrews County, TX?

Andrews County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 29 and first fall frost is November 7.

🌱

Your Andrews County Garden Planner — Free

A 22-page printable planner built for Andrews County (Zone 8a). 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 Andrews County, TX. 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.