When to Plant Cranberries in Denver County, CO
Denver County, Colorado gardeners: here's your May plan
Here's what deserves your attention in Denver County, Colorado this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
Before June arrives, get these ready
- Transplants going out: cranberries
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.
Denver County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.
At an elevation of 6,818 feet, Denver County receives approximately 20.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Cranberries during the growing season.
Denver County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.8
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 Denver County
How your county's soil matches Cranberries's growing requirements.
Soil pH
Your soil pH (6.4–7.8) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Denver County is excellent for Cranberries — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Cranberries.
How to Plant Cranberries
Plant Water Budget
Water stress score is 8/10 — 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| Jun | 6.5" | 1.3" | 5.2" | 🚿 Regular watering |
| Jul | 6.5" | 1.8" | 4.7" | 🚿 Regular watering |
| Aug | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Sep | 6.5" | 1.8" | 4.7" | 🚿 Regular watering |
| Oct | — | 1.8" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Denver 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 — Denver County, CO
Cranberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 4 | Jun 4 – Jun 18 |
· 36" apart · Rows 48" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| 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
135 days in Denver County
Growing Tips for Cranberries in Denver County
Direct sow Cranberries outdoors after May 14 in Denver County when soil has warmed and frost danger has passed.
Your 135.0-day growing season in Denver County is tight for Cranberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
Denver County receives only 20" of rain annually. Cranberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Denver County, CO?
Denver County is in Zone 6a with an average last frost of May 14. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Denver County, CO?
Denver County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.
Your Denver County Garden Planner — Free
A 24-page printable planner built for Denver 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.