When to plant Vinca (Annual) in Logan County County,
Plant Vinca (Annual) in Logan County County, between May 7 and May 21 — the only viable window. Zone 6a's short season (165 frost-free days) rules out a fall crop.
When to Plant Vinca (Annual) in Logan County, KS
This month in Logan County, Kansas
Here's what deserves your attention in Logan County, Kansas this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
Before July arrives, get these ready
- Starting indoors: vinca (annual)
- 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.
Logan County, Kansas is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 12, giving you a growing season of approximately 165 days.
At an elevation of 764 feet, Logan County receives approximately 22.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Vinca (Annual) during the growing season.
Logan County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.4
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 Logan County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (6.3–7.4) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Logan County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Jul 14 to harvest before frost.
Vinca (Annual) Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
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 | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Jul | 2.2" | 2" | 0.2" | 💧 Light watering |
| Aug | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Oct | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Nov | — | 1.8" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Logan 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 — Logan County, KS
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 19 | Feb 19 – Mar 5 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Bloom | July 16 | Jul 16 – Oct 22 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | — |
| 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 6a
📆 Growing Season
165 days in Logan County
Growing Tips for Vinca (Annual) in Logan County
Direct sow Vinca (Annual) outdoors after April 30 in Logan County when soil has warmed and frost danger has passed.
Logan County receives only 22" of rain annually. Vinca (Annual) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Logan County, KS?
Logan County is in Zone 6a with an average last frost of April 30. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Logan County, KS?
Logan County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 12.
When should I plant Vinca (Annual) in Logan County, ?
In Logan County, , plant Vinca (Annual) after the last frost (around April 30) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Logan County, for Vinca (Annual)?
Logan 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 Logan County's climate?
Yes — Vinca (Annual) grows well in Logan County's temperate climate. Logan County averages a 165-day frost-free season, with last frost around April 30 and first frost around October 12.
Your Logan County Garden Planner — Free
A 22-page printable planner built for Logan 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.