When to plant Vinca (Annual) in Viola,
Plant Vinca (Annual) in Viola during the brief April 2–April 16 window. With 216 frost-free days, fall plantings can't mature before November 4.
When to Plant Vinca (Annual) in Viola, DE
Your June planting checklist for Viola, DE
June is a pivotal month for Viola, DE gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Start vinca (annual) under lights
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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Collect vinca (annual) at their peak
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
July prep starts now
- 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.
Viola, Delaware is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 4, giving you a growing season of approximately 216 days.
At an elevation of 128 feet, Kent County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Vinca (Annual) during the growing season.
Viola Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.8
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 Viola
How your county's soil matches Vinca (Annual)'s growing requirements.
Soil pH
Your soil pH (5.8–6.8) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Kent County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.2%). Annual compost additions will help Vinca (Annual).
How to Plant Vinca (Annual)
Succession Planting Vinca (Annual)
Sow every 8 weeks. Last sowing by Aug 06 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" | 0" | ❄️ Dormant |
| Feb | — | 2.9" | 0" | ❄️ Dormant |
| Mar | — | 3.5" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Kent 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 — Viola, DE
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 22 | Jan 22 – Feb 5 |
| Transplant Outdoors | April 2 | Apr 2 – Apr 16 |
| Bloom | June 11 | Jun 11 – Oct 15 |
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
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
216 days in Kent County
Growing Tips for Vinca (Annual) in Viola
Direct sow Vinca (Annual) outdoors after April 02 in Kent 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
When should I plant Vinca (Annual) in Viola, ?
In Viola, , plant Vinca (Annual) after the last frost (around April 2) and before the first frost (around November 4). Best results when soil holds above 50°F.
What growing zone is Viola, for Vinca (Annual)?
Viola sits in USDA Zone 7b. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.
Can Vinca (Annual) grow in Viola's climate?
Yes — Vinca (Annual) grows well in Viola's temperate climate. Viola averages a 216-day frost-free season, with last frost around April 2 and first frost around November 4.
Your Kent County Garden Planner — Free
A 22-page printable planner built for Kent County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.