When to plant Vinca (Annual) in Alpine County, CA
Plant Vinca (Annual) in Alpine County during the brief May 26–June 9 window. With 137 frost-free days, fall plantings can't mature before October 3.
When to Plant Vinca (Annual) in Alpine County, CA
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.
Alpine County, California is in USDA Zone 6b. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.
At an elevation of 1,278 feet, Alpine County receives approximately 36.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Vinca (Annual) to ensure they mature before fall.
Alpine County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.3
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 | — | 7.1" | 0" | ❄️ Dormant |
| Feb | — | 8.7" | 0" | ❄️ Dormant |
| Mar | — | 5.7" | 0" | ❄️ Dormant |
| Apr | — | 2.7" | 0" | ❄️ Dormant |
| May | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Jun | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Oct | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 5.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Alpine County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Vinca (Annual) Planting Timeline — Alpine County, CA
Vinca (Annual) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | May 26 | May 26 – Jun 9 |
| Bloom | August 4 | Aug 4 – Nov 17 |
Plant 0.1" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| 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
137 days in Alpine County
Growing Tips for Alpine 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 Alpine County, CA?
Alpine County is in Zone 6b with an average last frost of May 19. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Alpine County, CA?
Alpine County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 19 and first fall frost is October 3.
When should I plant Vinca (Annual) in Alpine County, CA?
In Alpine County, CA, plant Vinca (Annual) after the last frost (around May 19) and before the first frost (around October 3). Best results when soil holds above 50°F.
What growing zone is Alpine County, CA for Vinca (Annual)?
Alpine 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 Alpine County's climate?
Yes — Vinca (Annual) grows well in Alpine County's temperate climate. Alpine County averages a 137-day frost-free season, with last frost around May 19 and first frost around October 3.
Your Alpine County Garden Planner — Free
A 22-page printable planner built for Alpine 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.