When to Plant Cranberries in Washtenaw County, MI
Top priorities for Washtenaw County, Michigan gardeners in May
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Washtenaw County, Michigan.
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Transplant cranberries outside
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
Cranberries are low-growing, vine-like shrubs that produce tart red berries in fall. They grow in acidic, boggy conditions and are surprisingly easy to cultivate.
Washtenaw County, Michigan is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 16, giving you a growing season of approximately 170 days.
At an elevation of 737 feet, Washtenaw County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Cranberries during the growing season.
Washtenaw County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
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 Washtenaw County
How your county's soil matches Cranberries's growing requirements.
Soil pH
Your soil pH (6.2–7.2) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.
Soil Texture
The silt loam soil in Washtenaw County is excellent for Cranberries — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Cranberries is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is excellent (4.5%) — Cranberries will thrive.
How to Plant Cranberries
Plant Water Budget
Monthly Watering Guide for Cranberries
Cranberries needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Cranberries Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| May | 6.5" | 4" | 2.5" | 💧 Light watering |
| Jun | 6.5" | 5.1" | 1.4" | 💧 Light watering |
| Jul | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Aug | 6.5" | 4.5" | 2" | 💧 Light watering |
| Sep | 6.5" | 3.2" | 3.3" | 🚿 Regular watering |
| Oct | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Washtenaw County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cranberries 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.
Cranberries Planting Timeline — Washtenaw County, MI
Cranberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
· 36" apart · Rows 48" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 4–5.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
170 days in Washtenaw County
Growing Tips for Cranberries in Washtenaw County
Direct sow Cranberries outdoors after April 29 in Washtenaw County when soil has warmed and frost danger has passed.
Your 170.0-day growing season in Washtenaw County is tight for Cranberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Create an acidic, consistently moist bed with peat moss. Cranberries do not need to be flooded to grow; flooding is only used for commercial harvesting. Mulch with sand in early spring.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Cranberries in Other Locations
Frequently Asked Questions
When should I plant Cranberries in Washtenaw County, MI?
Washtenaw County is in Zone 6a with an average last frost of April 29. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washtenaw County, MI?
Washtenaw County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 29 and first fall frost is October 16.
Your Washtenaw County Garden Planner — Free
A 24-page printable planner built for Washtenaw County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.