When to plant Vinca (Annual) in Hamilton County, IL
In Hamilton County, Vinca (Annual) is a single-season spring crop — there's no second fall window. Plant April 16–April 30 for an 70–90-day harvest, finishing well before the October 23 first frost.
When to Plant Vinca (Annual) in Hamilton County, IL
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.
Hamilton County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 23, giving you a growing season of approximately 197 days.
At an elevation of 524 feet, Hamilton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Vinca (Annual) during the growing season.
Hamilton County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Vinca (Annual) Planting Timeline — Hamilton County, IL
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
197 days in Hamilton County
Growing Tips for Hamilton 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 Hamilton County, IL?
Hamilton 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 Hamilton County, IL?
Hamilton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 23.
When should I plant Vinca (Annual) in Hamilton County, IL?
In Hamilton County, IL, plant Vinca (Annual) after the last frost (around April 9) and before the first frost (around October 23). Best results when soil holds above 50°F.
What growing zone is Hamilton County, IL for Vinca (Annual)?
Hamilton 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 Hamilton County's climate?
Yes — Vinca (Annual) grows well in Hamilton County's temperate climate. Hamilton County averages a 197-day frost-free season, with last frost around April 9 and first frost around October 23.
Your Hamilton County Garden Planner — Free
A 22-page printable planner built for Hamilton 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.