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

Deschutes County, Oregon Zone 6b June

June in the garden — Deschutes County, Oregon

Your garden in Deschutes County, Oregon is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost June 15
Avg. first frost September 13
Soil temp (4") 74°F
Watering High
Pest pressure High
Daylight 15.3 hrs
  1. Harden off and plant vinca (annual)

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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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.

Deschutes County, Oregon is in USDA Zone 6b. The average last spring frost is June 15 and the first fall frost is September 13, giving you a growing season of approximately 90 days.

At an elevation of 221 feet, Deschutes County receives approximately 54.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Vinca (Annual) to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Deschutes County, OR (Zone 6b) Very short season
90 days
Last Spring Frost June 15
90 growing days
First Fall Frost September 13

Deschutes County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 25 Transplant: Jun 10 🌸 Bloom: Aug 19 – Dec 2
Recommended (50%) ✗ May not fit
Start indoors: Apr 6 Transplant: Jun 22 🌸 Bloom: Aug 31 – Dec 14
Safe Start (90%) ✗ May not fit
Start indoors: Apr 17 Transplant: Jul 3 🌸 Bloom: Sep 11 – Dec 25

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 Deschutes County

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

Soil pH

Your soil pH (5.4–6.2) is more acidic than Vinca (Annual) prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — 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
2.6″/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 7.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 3" 0" ❄️ Dormant
Jun 2.2" 2.5" 0" ✅ Rainfall sufficient
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1" 1.2" 🚿 Regular watering
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 4.9" 0" ❄️ Dormant
Nov 7.8" 0" ❄️ Dormant
Dec 9.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Deschutes 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 ~860 GDD — county provides 967 GDD Good fit

Vinca (Annual) Planting Timeline — Deschutes County, OR

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 – Apr 20
Transplant Outdoors June 22 Jun 22 – Jul 6
Bloom August 31 Aug 31 – Dec 14

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

Month-by-Month Timeline

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

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

90 days in Deschutes County

Growing Tips for Vinca (Annual) in Deschutes County

Direct sow Vinca (Annual) outdoors after June 15 in Deschutes County when soil has warmed and frost danger has passed.

Your 90.0-day growing season in Deschutes County is tight for Vinca (Annual) (70.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Deschutes County, OR?

Deschutes County is in Zone 6b with an average last frost of June 15. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Deschutes County, OR?

Deschutes County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 15 and first fall frost is September 13.

🌱

Your Deschutes County Garden Planner — Free

A 22-page printable planner built for Deschutes 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 Deschutes County, OR. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.