When to Plant Vinca (Annual) in Hamilton County, TN
June to-do list for Hamilton County, Tennessee
Here's what deserves your attention in Hamilton County, Tennessee this month. Everything below is tailored to Zone 8a and timed around your local frost dates.
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Time to start vinca (annual) inside
Label every cell. You will absolutely forget which is which otherwise.
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Bring in the vinca (annual)
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
July will be here before you know it — start on
- 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.
Hamilton County, Tennessee is in USDA Zone 8a. The average last spring frost is March 28 and the first fall frost is November 1, giving you a growing season of approximately 218 days.
At an elevation of 3,918 feet, Hamilton County receives approximately 51.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Vinca (Annual) during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.
Hamilton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.9
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 Hamilton County
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (5.6–6.9) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Hamilton County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Aug 03 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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Hamilton 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 — Hamilton County, TN
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 17 | Jan 17 – Jan 31 |
| Transplant Outdoors | March 21 | Mar 21 – Apr 4 |
| Bloom | May 30 | May 30 – Oct 17 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | — |
| March | Transplant Outdoors |
| April | Transplant Outdoors |
| May | Bloom |
| 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 8a
📆 Growing Season
218 days in Hamilton County
Growing Tips for Vinca (Annual) in Hamilton County
Direct sow Vinca (Annual) outdoors after March 28 in Hamilton 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 Hamilton County, TN?
Hamilton County is in Zone 8a with an average last frost of March 28. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hamilton County, TN?
Hamilton County, Tennessee is in USDA Hardiness Zone 8a. The average last spring frost is March 28 and first fall frost is November 1.
Your Hamilton County Garden Planner — Free
A 22-page printable planner built for Hamilton County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.