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When to Plant Vinca (Annual) in Baker County, OR

Baker County, Oregon Zone 6b June

Your June gardening checklist

Welcome to June in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 30
Avg. first frost September 12
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 15.4 hrs
  1. Plant out vinca (annual)

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

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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.

Baker County, Oregon is in USDA Zone 6b. The average last spring frost is May 30 and the first fall frost is September 12, giving you a growing season of approximately 105 days.

At an elevation of 1,398 feet, Baker County receives approximately 16.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Vinca (Annual) during the growing season. With low rainfall, drip irrigation is essential for growing Vinca (Annual) successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Baker County, OR (Zone 6b) Short season
105 days
Last Spring Frost May 30
105 growing days
First Fall Frost September 12
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Baker County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 10 Transplant: May 26 🌸 Bloom: Aug 4 – Nov 17
Recommended (50%) ✗ May not fit
Start indoors: Mar 21 Transplant: Jun 6 🌸 Bloom: Aug 15 – Nov 28
Safe Start (90%) ✗ May not fit
Start indoors: Apr 10 Transplant: Jun 26 🌸 Bloom: Sep 4 – Dec 18

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 Baker County

How your county's soil matches Vinca (Annual)'s growing requirements.

Soil pH

Your soil pH (5.3–6.5) is more acidic than Vinca (Annual) prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Baker County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Vinca (Annual).

Organic Matter

Organic matter is excellent (4.8%) — Vinca (Annual) will thrive.

How to Plant Vinca (Annual)

0.1"
Planting Depth
10"
Between Plants
12"
Between Rows

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 2.3" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.1" 0" ❄️ Dormant
May 2.2" 1.1" 1.1" 🚿 Regular watering
Jun 2.2" 0.6" 1.6" 🚿 Regular watering
Jul 2.2" 0.2" 2" 🚿 Regular watering
Aug 2.2" 0.3" 1.9" 🚿 Regular watering
Sep 2.2" 0.8" 1.4" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 2.5" 0" ❄️ Dormant
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Baker 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) needs ~1,160 GDD — county provides 1,522 GDD Excellent fit

Vinca (Annual) Planting Timeline — Baker County, OR

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors June 6 Jun 6 – Jun 20
Bloom August 15 Aug 15 – Nov 28

Plant 0.1" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May
June Transplant Outdoors
July
August Bloom
September Bloom
October Bloom
November Bloom
December
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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: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

105 days in Baker County

Growing Tips for Vinca (Annual) in Baker County

Direct sow Vinca (Annual) outdoors after May 30 in Baker County when soil has warmed and frost danger has passed.

Baker County receives only 17" 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 →

Frequently Asked Questions

When should I plant Vinca (Annual) in Baker County, OR?

Baker County is in Zone 6b with an average last frost of May 30. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Baker County, OR?

Baker County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is May 30 and first fall frost is September 12.

🌱

Your Baker County Garden Planner — Free

A 22-page printable planner built for Baker 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Baker County, OR. Local conditions may vary. Last updated: June 2026.

Sources & credits

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