When to Plant Vinca (Annual) in Frio County, TX
June in Frio County, Texas — your action list
We've pulled the most time-sensitive tasks for Frio County, Texas this June and put them front and centre. Tackle them in order.
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Pick vinca (annual)
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
A few tasks this June that'll pay off in July
- 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.
Frio County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.
At an elevation of 3,892 feet, Frio County receives approximately 51 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Vinca (Annual) during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.
Frio County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.2
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 Frio County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (6.4–7.2) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Frio County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Vinca (Annual).
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Aug 28 to harvest before frost.
Vinca (Annual) Water Budget
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 | — | 1.2" | 0" | ❄️ Dormant |
| Feb | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Mar | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 7.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 9.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 6.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Frio 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 — Frio County, TX
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 18 | Dec 18 – Jan 1 |
| Transplant Outdoors | February 5 | Feb 5 – Feb 19 |
| Bloom | April 16 | Apr 16 – Oct 15 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| 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 9a
📆 Growing Season
273 days in Frio County
Growing Tips for Vinca (Annual) in Frio County
Direct sow Vinca (Annual) outdoors after February 26 in Frio 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 Frio County, TX?
Frio County is in Zone 9a with an average last frost of February 26. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Frio County, TX?
Frio County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.
Your Frio County Garden Planner — Free
A 22-page printable planner built for Frio County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.