When to Plant Haskaps in Mercer County, NJ
May to-do list for Mercer County, New Jersey
Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.
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Get haskaps in the ground
Frost risk is low now in Mercer County, New Jersey. If you've been covering beds overnight, you can stop.
Haskaps (honeyberries) are extremely cold-hardy shrubs producing elongated blue berries with a complex blueberry-raspberry flavor. They fruit very early in the season.
Mercer County, New Jersey is in USDA Zone 7a. The average last spring frost is April 12 and the first fall frost is October 29, giving you a growing season of approximately 200 days.
At an elevation of 4 feet, Mercer County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Haskaps during the growing season.
Mercer County Soil Profile
Soil Type
Silt Loam
Soil pH
5-6.7
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.
Soil Compatibility in Mercer County
How your county's soil matches Haskaps's growing requirements.
Soil pH
Your soil pH (5.0–6.7) overlaps with Haskaps's range (5.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Mercer County is excellent for Haskaps — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Haskaps.
How to Plant Haskaps
Plant Water Budget
Monthly Watering Guide for Haskaps
Haskaps needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Haskaps Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 4.1" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Nov | — | 3.8" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Mercer County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Haskaps 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.
Haskaps Planting Timeline — Mercer County, NJ
Haskaps Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 3 | May 3 – May 17 |
· 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
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
200 days in Mercer County
Growing Tips for Haskaps in Mercer County
Direct sow Haskaps outdoors after April 12 in Mercer County when soil has warmed and frost danger has passed.
Your 200.0-day growing season in Mercer County is tight for Haskaps (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant at least two different varieties for cross-pollination. Fruits ripen 2-3 weeks before strawberries. Protect from birds. Very low maintenance once established. Tolerates extreme cold.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Haskaps in Other Locations
Frequently Asked Questions
When should I plant Haskaps in Mercer County, NJ?
Mercer County is in Zone 7a with an average last frost of April 12. Plan your Haskaps planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mercer County, NJ?
Mercer County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is April 12 and first fall frost is October 29.
Your Mercer County Garden Planner — Free
A 24-page printable planner built for Mercer 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.