When to plant Vinca (Annual) in Phelps County, MO
Phelps County's short 198-day growing season means one Vinca (Annual) planting between April 16 and April 30. No fall crop in Zone 6b.
When to Plant Vinca (Annual) in Phelps 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.
Phelps County, Missouri is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 24, giving you a growing season of approximately 198 days.
At an elevation of 1,057 feet, Phelps County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Vinca (Annual) during the growing season.
Phelps County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Vinca (Annual) Planting Timeline — Phelps County, MO
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 29 | Jan 29 – Feb 12 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Bloom | June 25 | Jun 25 – Oct 8 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| 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 6b
📆 Growing Season
198 days in Phelps County
Growing Tips for Phelps 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 Phelps County, MO?
Phelps County is in Zone 6b with an average last frost of April 9. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Phelps County, MO?
Phelps County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 24.
When should I plant Vinca (Annual) in Phelps County, MO?
In Phelps County, MO, plant Vinca (Annual) after the last frost (around April 9) and before the first frost (around October 24). Best results when soil holds above 50°F.
What growing zone is Phelps County, MO for Vinca (Annual)?
Phelps County sits in USDA Zone 6b. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.
Can Vinca (Annual) grow in Phelps County's climate?
Yes — Vinca (Annual) grows well in Phelps County's temperate climate. Phelps County averages a 198-day frost-free season, with last frost around April 9 and first frost around October 24.
Your Phelps County Garden Planner — Free
A 22-page printable planner built for Phelps County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.