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When to Plant Alpine Strawberries in Jefferson County, OR

Jefferson County, Oregon Zone 7a May

Jefferson County, Oregon gardeners: here's your May plan

Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost June 9
Avg. first frost September 19
Soil temp (4") 61°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
Coming up in June — start thinking about
  • Transplants going out: alpine strawberries

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Alpine strawberries are small, intensely flavored wild-type strawberries that fruit continuously from spring to frost. They do not produce runners and make excellent edging plants.

Jefferson County, Oregon is in USDA Zone 7a. The average last spring frost is June 9 and the first fall frost is September 19, giving you a growing season of approximately 102 days.

At an elevation of 21 feet, Jefferson County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Alpine Strawberries to ensure they mature before fall.

Jefferson County, OR (Zone 7a) Short season
102 days
Last Spring Frost June 9
102 growing days
First Fall Frost September 19

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (251 days to spare)
Transplant: Jun 20 🍅 Harvest: Sep 19 – Jan 2
Recommended (50%) ✓ Fits season (250 days to spare)
Transplant: Jun 30 🍅 Harvest: Sep 29 – Jan 12
Safe Start (90%) ✓ Fits season (254 days to spare)
Transplant: Jul 13 🍅 Harvest: Oct 12 – Jan 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 Jefferson County

How your county's soil matches Alpine Strawberries's growing requirements.

Soil pH

Your soil pH (5.3–6.7) overlaps with Alpine Strawberries's range (5.5–6.8), though not a perfect match.

Soil Texture

The silt loam soil in Jefferson County is excellent for Alpine Strawberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.0%) — Alpine Strawberries will thrive.

How to Plant Alpine Strawberries

12"
Between Plants
24"
Between Rows

Plant Water Budget

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

Monthly Watering Guide for Alpine Strawberries

Alpine Strawberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Alpine Strawberries Needs Rainfall You Supplement Action
Jan 4.8" 0" ❄️ Dormant
Feb 3.7" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 1.8" 0" ❄️ Dormant
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 0.5" 3.8" 🚿 Regular watering
Aug 4.3" 0.6" 3.7" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 3.2" 0" ❄️ Dormant
Nov 6.1" 0" ❄️ Dormant
Dec 5.5" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Alpine Strawberries 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.

Alpine Strawberries needs ~1,249 GDD — county provides 943 GDD May not mature

Alpine Strawberries Planting Timeline — Jefferson County, OR

Alpine Strawberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 30 Jun 30 – Jul 14
Harvest September 29 Sep 29 – Jan 12

· 12" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Harvest
February
March
April
May
June Transplant Outdoors
July Transplant Outdoors
August
September Harvest
October Harvest
November Harvest
December Harvest

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–180 days

🧪 Soil pH

Needs 5.5–6.8 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

102 days in Jefferson County

Growing Tips for Alpine Strawberries in Jefferson County

Direct sow Alpine Strawberries outdoors after June 09 in Jefferson County when soil has warmed and frost danger has passed.

Your 102.0-day growing season in Jefferson County is tight for Alpine Strawberries (90.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Unlike regular strawberries, alpines do not spread by runners. Harvest tiny, intensely aromatic berries frequently. Grow well in partial shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Alpine Strawberries in Jefferson County, OR?

Jefferson County is in Zone 7a with an average last frost of June 9. Plan your Alpine Strawberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, OR?

Jefferson County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is June 9 and first fall frost is September 19.

🌱

Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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