When to plant Vinca (Annual) in Randolph County, MO
In Randolph County, Vinca (Annual) is a single-season spring crop — there's no second fall window. Plant April 22–May 6 for an 70–90-day harvest, finishing well before the October 18 first frost.
When to Plant Vinca (Annual) in Randolph County, MO
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.
Randolph County, Missouri is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.
At an elevation of 1,243 feet, Randolph County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Vinca (Annual) during the growing season.
Randolph County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Vinca (Annual) Planting Timeline — Randolph County, MO
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 4 | Feb 4 – Feb 18 |
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Bloom | July 1 | Jul 1 – Oct 7 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6a
📆 Growing Season
186 days in Randolph County
Growing Tips for Randolph County
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 Randolph County, MO?
Randolph County is in Zone 6a with an average last frost of April 15. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Randolph County, MO?
Randolph County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 18.
When should I plant Vinca (Annual) in Randolph County, MO?
In Randolph County, MO, plant Vinca (Annual) after the last frost (around April 15) and before the first frost (around October 18). Best results when soil holds above 50°F.
What growing zone is Randolph County, MO for Vinca (Annual)?
Randolph County sits in USDA Zone 6a. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.
Can Vinca (Annual) grow in Randolph County's climate?
Yes — Vinca (Annual) grows well in Randolph County's temperate climate. Randolph County averages a 186-day frost-free season, with last frost around April 15 and first frost around October 18.
Your Randolph County Garden Planner — Free
A 22-page printable planner built for Randolph County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.