When to Plant Vinca (Annual) in Goliad County, TX
Goliad County, Texas gardeners: here's your June plan
June is a pivotal month for Goliad County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Basket week: vinca (annual)
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Before July arrives, get these ready
- First harvests: vinca (annual)
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.
Goliad County, Texas is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is December 4, giving you a growing season of approximately 283 days.
At an elevation of 3,928 feet, Goliad County receives approximately 62.6 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Vinca (Annual) may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.
Goliad County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.3
Drainage
Well Drained
Vinca (Annual) Planting Risk Windows
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 Goliad County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (6.3–7.3) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Goliad County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Sep 05 to harvest before frost.
Vinca (Annual) Water Budget
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 10.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.2" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Dec | 2.2" | 1.6" | 0.6" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Goliad 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) Planting Timeline — Goliad County, TX
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 16 | Dec 16 – Dec 30 |
| Transplant Outdoors | January 27 | Jan 27 – Feb 10 |
| Bloom | April 7 | Apr 7 – Oct 20 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors |
| February | Transplant Outdoors |
| March | — |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | Start Indoors |
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 9b
📆 Growing Season
283 days in Goliad County
Growing Tips for Vinca (Annual) in Goliad County
Direct sow Vinca (Annual) outdoors after February 24 in Goliad 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 →
Vinca (Annual) in Other Locations
Frequently Asked Questions
When should I plant Vinca (Annual) in Goliad County, TX?
Goliad County is in Zone 9b with an average last frost of February 24. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Goliad County, TX?
Goliad County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is December 4.
Your Goliad County Garden Planner — Free
A 22-page printable planner built for Goliad County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.