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When to Plant Jostaberry in Marion County, IL

Marion County, Illinois Zone 6b May

May to-do list for Marion County, Illinois

Here's what deserves your attention in Marion County, Illinois this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost April 10
Avg. first frost October 19
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Get jostaberry in the ground

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

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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.

Marion County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 964 feet, Marion County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Jostaberry during the growing season.

Marion County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 26
Recommended (50%) ✓ Fits season
Transplant: May 1
Safe Start (90%) ✓ Fits season
Transplant: May 11

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 Marion County

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

Soil pH

Your soil pH (6.1–7.0) is more alkaline than Jostaberry prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Jostaberry.

Organic Matter

Organic matter is excellent (4.4%) — Jostaberry will thrive.

How to Plant Jostaberry

48"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 708 gal / 100 sq ft

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 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 3.1" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Marion 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 ~15,284 GDD — county provides 3,216 GDD May not mature

Jostaberry Planting Timeline — Marion County, IL

Jostaberry Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 – May 15

· 48" apart · Rows 72" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
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 6b

📆 Growing Season

192 days in Marion County

Growing Tips for Jostaberry in Marion County

Direct sow Jostaberry outdoors after April 10 in Marion County when soil has warmed and frost danger has passed.

Your 192.0-day growing season in Marion County is tight for Jostaberry (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Marion County, IL?

Marion County is in Zone 6b with an average last frost of April 10. Plan your Jostaberry planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marion County, IL?

Marion County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

🌱

Your Marion County Garden Planner — Free

A 24-page printable planner built for Marion 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 Marion County, IL. 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.