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When to plant Jostaberry in Summit County, CO

Summit County's short 80-day growing season means one Jostaberry planting between July 7 and July 21. No fall crop in Zone 5a.

When to Plant Jostaberry in Summit County, CO

Summit County, Colorado Zone 5a June

Your June game plan for Summit County, Colorado

We've pulled the most time-sensitive tasks for Summit County, Colorado this June and put them front and centre. Tackle them in order.

Avg. last frost June 16
Avg. first frost September 4
Soil temp (4") 45°F
Watering High
Pest pressure High
Daylight 14.8 hrs
Looking ahead to July
  • Transplants going out: jostaberry

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Jostaberry is a thornless hybrid of black currant and gooseberry, producing medium-sized, dark berries with a complex, tart-sweet flavor. It is vigorous and disease-resistant.

Summit County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.

At an elevation of 7,005 feet, Summit County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Jostaberry to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Jostaberry successfully. Mulch heavily to conserve soil moisture.

Summit County, CO (Zone 5a) Very short season
80 days
Last Spring Frost June 16
80 growing days
First Fall Frost September 4

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Jostaberry Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jul 1
Recommended (50%) ✓ Fits season
Transplant: Jul 7
Safe Start (90%) ✓ Fits season
Transplant: Jul 17

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 Summit County

How your county's soil matches Jostaberry's growing requirements.

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Jostaberry prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Summit County is excellent for Jostaberry — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Jostaberry.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Jostaberry.

How to Plant Jostaberry

48"
Between Plants
72"
Between Rows

Jostaberry Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 326 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Jostaberry

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

Month Jostaberry Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.8" 0" ❄️ Dormant
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Jostaberry 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.

Jostaberry needs ~9,809 GDD — county provides 860 GDD May not mature

Jostaberry Planting Timeline — Summit County, CO

Jostaberry Planting Calendar

Activity When Date Range
Transplant Outdoors July 7 Jul 7 – Jul 21

· 48" apart · Rows 72" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

80 days in Summit County

Growing Tips for Jostaberry in Summit County

Direct sow Jostaberry outdoors after June 16 in Summit County when soil has warmed and frost danger has passed.

Your 80.0-day growing season in Summit County is tight for Jostaberry (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

Summit County receives only 18" of rain annually. Jostaberry needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant in rich, well-drained soil. No special pruning required beyond removing old wood. Self-fertile but yields improve with a second bush. Berries ripen midsummer.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Jostaberry in Summit County, CO?

Summit County is in Zone 5a with an average last frost of June 16. Plan your Jostaberry planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, CO?

Summit County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 4.

When should I plant Jostaberry in Summit County, CO?

In Summit County, CO, plant Jostaberry after the last frost (around June 16) and before the first frost (around September 4). Best results when soil holds above 50°F.

What growing zone is Summit County, CO for Jostaberry?

Summit County sits in USDA Zone 5a. Jostaberry grows reliably in zones 3a through 8b, so it's a good fit here.

Can Jostaberry grow in Summit County's climate?

Yes — Jostaberry grows well in Summit County's temperate climate. Summit County averages a 80-day frost-free season, with last frost around June 16 and first frost around September 4.

🌱

Your Summit County Garden Planner — Free

A 22-page printable planner built for Summit County (Zone 5a). 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 Summit County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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