When to plant Vinca (Annual) in Montgomery County, IL
Montgomery County sits in cold Zone 6b. Plant Vinca (Annual) April 20–May 4 for the single annual harvest; the October 21 first frost closes the window.
When to Plant Vinca (Annual) in Montgomery 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.
Montgomery County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 1,331 feet, Montgomery County receives approximately 30.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Vinca (Annual) during the growing season.
Montgomery County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.2
Drainage
Well Drained
Monthly Watering Guide for Vinca (Annual)
Vinca (Annual) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Vinca (Annual) Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Montgomery County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Vinca (Annual) Planting Timeline — Montgomery County, IL
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 2 | Feb 2 – Feb 16 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Bloom | June 29 | Jun 29 – Oct 12 |
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 | 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
191 days in Montgomery County
Growing Tips for Montgomery 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 Montgomery County, IL?
Montgomery County is in Zone 6b with an average last frost of April 13. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Montgomery County, IL?
Montgomery County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 21.
When should I plant Vinca (Annual) in Montgomery County, IL?
In Montgomery County, IL, plant Vinca (Annual) after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Montgomery County, IL for Vinca (Annual)?
Montgomery 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 Montgomery County's climate?
Yes — Vinca (Annual) grows well in Montgomery County's temperate climate. Montgomery County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Montgomery County Garden Planner — Free
A 22-page printable planner built for Montgomery 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.