When to plant Vinca (Annual) in Boone County, MO
Boone County sits in cold Zone 6b. Plant Vinca (Annual) April 17–May 1 for the single annual harvest; the October 25 first frost closes the window.
When to Plant Vinca (Annual) in Boone County, MO
Boone County, Missouri gardeners: here's your June plan
Each item below is timed to Boone County, Missouri's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Get vinca (annual) seeds going inside
You're about 17 weeks out from your last frost — the perfect window to get these germinating indoors.
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Pick vinca (annual)
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Looking ahead to July
- 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.
Boone County, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 25, giving you a growing season of approximately 198 days.
At an elevation of 727 feet, Boone County receives approximately 33.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Vinca (Annual) during the growing season.
Boone County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-7.1
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 Boone County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (5.6–7.1) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Boone County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Jul 27 to harvest before frost.
Vinca (Annual) Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Boone 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 — Boone County, MO
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 30 | Jan 30 – Feb 13 |
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Bloom | June 26 | Jun 26 – Oct 9 |
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 | Transplant Outdoors |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
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 6b
📆 Growing Season
198 days in Boone County
Growing Tips for Vinca (Annual) in Boone County
Direct sow Vinca (Annual) outdoors after April 10 in Boone County when soil has warmed and frost danger has passed.
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 Boone County, MO?
Boone County is in Zone 6b with an average last frost of April 10. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Boone County, MO?
Boone County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 25.
When should I plant Vinca (Annual) in Boone County, MO?
In Boone County, MO, plant Vinca (Annual) after the last frost (around April 10) and before the first frost (around October 25). Best results when soil holds above 50°F.
What growing zone is Boone County, MO for Vinca (Annual)?
Boone 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 Boone County's climate?
Yes — Vinca (Annual) grows well in Boone County's temperate climate. Boone County averages a 198-day frost-free season, with last frost around April 10 and first frost around October 25.
Your Boone County Garden Planner — Free
A 22-page printable planner built for Boone 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.