When to plant Vinca (Annual) in Simpson County, MS
Simpson County sits in cold Zone 8b. Plant Vinca (Annual) February 24–March 10 for the single annual harvest; the November 15 first frost closes the window.
When to Plant Vinca (Annual) in Simpson County, MS
This month in Simpson County, Mississippi
We've pulled the most time-sensitive tasks for Simpson County, Mississippi this June and put them front and centre. Tackle them in order.
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Harvest vinca (annual) as they ripen
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
July will be here before you know it — start on
- 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.
Simpson County, Mississippi is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 15, giving you a growing season of approximately 250 days.
At an elevation of 90 feet, Simpson County receives approximately 48.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97°F, so Vinca (Annual) may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Vinca (Annual), but amend with compost to improve drainage and prevent root rot.
Simpson County Soil Profile
Soil Type
Clay Loam
Soil pH
5.6-6.8
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 Simpson County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (5.6–6.8) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The clay loam soil in Simpson County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
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 17 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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 4" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Simpson 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 — Simpson County, MS
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 30 | Dec 30 – Jan 13 |
| Transplant Outdoors | February 24 | Feb 24 – Mar 10 |
| Bloom | May 5 | May 5 – Oct 6 |
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 | 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 8b
📆 Growing Season
250 days in Simpson County
Growing Tips for Vinca (Annual) in Simpson County
Direct sow Vinca (Annual) outdoors after March 10 in Simpson County when soil has warmed and frost danger has passed.
With Simpson County's clay soil (32% clay), work in 3-4 inches of compost before planting Vinca (Annual). Avoid tilling when soil is wet to prevent compaction.
With summer highs reaching 97°F in Simpson 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 →
Vinca (Annual) in Other Locations
Frequently Asked Questions
When should I plant Vinca (Annual) in Simpson County, MS?
Simpson County is in Zone 8b with an average last frost of March 10. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Simpson County, MS?
Simpson County, Mississippi is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 15.
When should I plant Vinca (Annual) in Simpson County, MS?
In Simpson County, MS, plant Vinca (Annual) after the last frost (around March 10) and before the first frost (around November 15). Best results when soil holds above 50°F.
What growing zone is Simpson County, MS for Vinca (Annual)?
Simpson 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 Simpson County's climate?
Yes — Vinca (Annual) grows well in Simpson County's temperate climate. Simpson County averages a 250-day frost-free season, with last frost around March 10 and first frost around November 15.
Your Simpson County Garden Planner — Free
A 22-page printable planner built for Simpson 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.