When to Plant Cranberries in Boone County, IL
May to-do list for Boone County, Illinois
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Time to transplant cranberries
Frost risk is low now in Boone County, Illinois. If you've been covering beds overnight, you can stop.
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.
Boone County, Illinois is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.
At an elevation of 512 feet, Boone County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Cranberries to ensure they mature before fall.
Boone County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.8
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 Boone County
How your county's soil matches Cranberries's growing requirements.
Soil pH
Your soil pH (6.0–6.8) 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 Boone 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 moderate (3.8%). Annual compost additions will help Cranberries.
How to Plant Cranberries
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| May | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Jun | 6.5" | 5.7" | 0.8" | 💧 Light watering |
| Jul | 6.5" | 4.9" | 1.6" | 💧 Light watering |
| Aug | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Sep | 6.5" | 3.5" | 3" | 💧 Light watering |
| Oct | 6.5" | 3.5" | 3" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Boone 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 — Boone County, IL
Cranberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 14 | May 14 – May 28 |
· 36" apart · Rows 48" 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
1.5"/week · 2-3 times/week
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 4–5.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
176 days in Boone County
Growing Tips for Cranberries in Boone County
Direct sow Cranberries outdoors after April 23 in Boone County when soil has warmed and frost danger has passed.
Your 176.0-day growing season in Boone 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 Boone County, IL?
Boone County is in Zone 5b with an average last frost of April 23. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Boone County, IL?
Boone County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 16.
Your Boone County Garden Planner — Free
A 24-page printable planner built for Boone County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.