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When to Plant Cranberries in Lake County, CO

Lake County, Colorado Zone 5a May

May to-do list for Lake County, Colorado

May is a pivotal month for Lake County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost June 21
Avg. first frost August 30
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.1 hrs

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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.

Lake County, Colorado is in USDA Zone 5a. The average last spring frost is June 21 and the first fall frost is August 30, giving you a growing season of approximately 70 days.

At an elevation of 7,687 feet, Lake County receives approximately 21.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Cranberries to ensure they mature before fall.

Lake County, CO (Zone 5a) Very short season
70 days
Last Spring Frost June 21
70 growing days
First Fall Frost August 30
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Lake County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jul 7
Recommended (50%) ✓ Fits season
Transplant: Jul 12
Safe Start (90%) ✓ Fits season
Transplant: Jul 18

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 Lake County

How your county's soil matches Cranberries's growing requirements.

Soil pH

Your soil pH (6.6–8.2) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Lake County is excellent for Cranberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Cranberries.

How to Plant Cranberries

36"
Between Plants
48"
Between Rows

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.3″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 170 gal / 100 sq ft
Drought risk

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 1.5" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 2.7" 0" ❄️ Dormant
Jun 6.5" 1.4" 5.1" 🚿 Regular watering
Jul 6.5" 2.1" 4.4" 🚿 Regular watering
Aug 6.5" 2.2" 4.3" 🚿 Regular watering
Sep 1.6" 0" ❄️ Dormant
Oct 2.1" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Aug in Lake 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 needs ~11,178 GDD — county provides 857 GDD May not mature

Cranberries Planting Timeline — Lake County, CO

Cranberries Planting Calendar

Activity When Date Range
Transplant Outdoors July 12 Jul 12 – Jul 26

· 36" apart · Rows 48" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July Transplant Outdoors
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 4–5.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

70 days in Lake County

Growing Tips for Cranberries in Lake County

Direct sow Cranberries outdoors after June 21 in Lake County when soil has warmed and frost danger has passed.

Your 70.0-day growing season in Lake County is tight for Cranberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

Lake County receives only 21" 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 →

Frequently Asked Questions

When should I plant Cranberries in Lake County, CO?

Lake County is in Zone 5a with an average last frost of June 21. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, CO?

Lake County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 21 and first fall frost is August 30.

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Your Lake County Garden Planner — Free

A 24-page printable planner built for Lake County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lake County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.