When to Plant Jostaberry in Kingston, ON
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.
Kingston, Ontario is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 17, giving you a growing season of approximately 187 days.
At an elevation of 305 feet, Kingston receives approximately 36.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 84°F, so choose short-season varieties of Jostaberry to ensure they mature before fall. Clay soil retains moisture well for Jostaberry, but amend with compost to improve drainage and prevent root rot.
Kingston Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Plant Planting Risk Windows
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.
How to Plant Jostaberry
Plant Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Kingston). 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 Planting Timeline — Kingston, ON
Jostaberry Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 4 | May 4 – May 18 |
· 48" apart · Rows 72" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 · Only during dry spells
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 6–6.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
187 days in Kingston
Growing Tips for Jostaberry in Kingston
Your 187.0-day growing season in Kingston 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 →
Jostaberry in Other Locations
Frequently Asked Questions
When should I plant Jostaberry in Kingston, ON?
Kingston is in Zone 6b with an average last frost of April 13. Plan your Jostaberry planting based on this frost date — see the calendar above for exact timing.
What planting zone is Kingston, ON?
Kingston, Ontario is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 17.
Your Kingston Garden Planner — Free
A 24-page printable planner built for Kingston (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.