When to plant Vinca (Annual) in Marengo County, AL
Plant Vinca (Annual) in Marengo County during the brief February 27–March 13 window. With 245 frost-free days, fall plantings can't mature before November 13.
When to Plant Vinca (Annual) in Marengo County, AL
June in the garden — Marengo County, Alabama
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Marengo County, Alabama.
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Start harvesting vinca (annual)
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
July prep starts now
- 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.
Marengo County, Alabama is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 13, giving you a growing season of approximately 245 days.
At an elevation of 453 feet, Marengo County receives approximately 59.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Vinca (Annual) during the growing season. Clay soil retains moisture well for Vinca (Annual), but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.
Marengo County Soil Profile
Soil Type
Clay Loam
Soil pH
5.2-6.7
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 Marengo County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (5.2–6.7) is more acidic than Vinca (Annual) prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The clay loam soil in Marengo County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Aug 15 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 | — | 4.5" | 0" | ❄️ Dormant |
| Feb | — | 5" | 0" | ❄️ Dormant |
| Mar | 2.2" | 5.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Marengo 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 — Marengo County, AL
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 2 | Jan 2 – Jan 16 |
| Transplant Outdoors | February 27 | Feb 27 – Mar 13 |
| Bloom | May 8 | May 8 – Oct 9 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | — |
| May | Bloom |
| 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: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
245 days in Marengo County
Growing Tips for Vinca (Annual) in Marengo County
Direct sow Vinca (Annual) outdoors after March 13 in Marengo County when soil has warmed and frost danger has passed.
With Marengo County's clay soil (30% clay), work in 3-4 inches of compost before planting Vinca (Annual). Avoid tilling when soil is wet to prevent compaction.
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 Marengo County, AL?
Marengo County is in Zone 8b with an average last frost of March 13. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marengo County, AL?
Marengo County, Alabama is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 13.
When should I plant Vinca (Annual) in Marengo County, AL?
In Marengo County, AL, plant Vinca (Annual) after the last frost (around March 13) and before the first frost (around November 13). Best results when soil holds above 50°F.
What growing zone is Marengo County, AL for Vinca (Annual)?
Marengo County sits in USDA Zone 8b. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.
Can Vinca (Annual) grow in Marengo County's climate?
Yes — Vinca (Annual) grows well in Marengo County's temperate climate. Marengo County averages a 245-day frost-free season, with last frost around March 13 and first frost around November 13.
Your Marengo County Garden Planner — Free
A 22-page printable planner built for Marengo 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.