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When to Plant Vinca (Annual) in Val Verde County, TX

Val Verde County, Texas Zone 8b June

Your June gardening checklist

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 February 17
Avg. first frost December 7
Soil temp (4") 72°F
Watering High
Pest pressure High
Daylight 13.9 hrs
  1. Basket week: vinca (annual)

    If you can't use it all right away, check the food-preservation section of your planner.

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.

Val Verde County, Texas is in USDA Zone 8b. The average last spring frost is February 17 and the first fall frost is December 7, giving you a growing season of approximately 293 days.

At an elevation of 3,979 feet, Val Verde County receives approximately 53.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98°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
Val Verde County, TX (Zone 8b) Year-round
293 days
Last Spring Frost February 17
293 growing days
First Fall Frost December 7
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Val Verde County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.7-8.1

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (82 days to spare)
Start indoors: Dec 4 Transplant: Jan 29 🌸 Bloom: Apr 9 – Sep 10
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Dec 9 Transplant: Feb 3 🌸 Bloom: Apr 14 – Sep 15
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Dec 29 Transplant: Feb 23 🌸 Bloom: May 4 – Oct 5

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 Val Verde County

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

Soil pH

Your soil pH (7.7–8.1) is more alkaline than Vinca (Annual) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Val Verde 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 (0.9%). 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)

4
successive plantings in your 293-day season

Sow every 8 weeks. Last sowing by Sep 08 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 3.8" 0" ❄️ Dormant
Feb 2.2" 3.1" 0" ✅ Rainfall sufficient
Mar 2.2" 2.8" 0" ✅ Rainfall sufficient
Apr 2.2" 1.7" 0.5" 💧 Light watering
May 2.2" 1.1" 1.1" 🚿 Regular watering
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 9.6" 0" ✅ Rainfall sufficient
Aug 2.2" 11.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.2" 0" ✅ Rainfall sufficient
Oct 2.2" 4.3" 0" ✅ Rainfall sufficient
Nov 2.2" 3.3" 0" ✅ Rainfall sufficient
Dec 2.2" 4" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Val Verde 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 ~1,880 GDD — county provides 6,909 GDD Excellent fit

Vinca (Annual) Planting Timeline — Val Verde County, TX

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors December 9 Dec 9 – Dec 23
Transplant Outdoors February 3 Feb 3 – Feb 17
Bloom April 14 Apr 14 – Sep 15

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

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December Start Indoors
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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 8b

📆 Growing Season

293 days in Val Verde County

Growing Tips for Vinca (Annual) in Val Verde County

Direct sow Vinca (Annual) outdoors after February 17 in Val Verde County when soil has warmed and frost danger has passed.

Sandy soil in Val Verde 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 98°F in Val Verde 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 Val Verde County, TX?

Val Verde County is in Zone 8b with an average last frost of February 17. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Val Verde County, TX?

Val Verde County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is February 17 and first fall frost is December 7.

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Your Val Verde County Garden Planner — Free

A 22-page printable planner built for Val Verde County (Zone 8b). 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 Val Verde 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.