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When to Plant Raspberries in Grand County, CO

Grand County, Colorado Zone 5a May

Top priorities for Grand County, Colorado gardeners in May

We've pulled the most time-sensitive tasks for Grand County, Colorado this May and put them front and centre. Tackle them in order.

Avg. last frost May 28
Avg. first frost September 19
Soil temp (4") 42°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
June prep starts now
  • Transplants going out: raspberries

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Raspberries are beloved bramble fruits producing sweet, delicate berries in red, golden, black, and purple varieties. They spread by underground runners and are very productive.

Grand County, Colorado is in USDA Zone 5a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.

At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Raspberries to ensure they mature before fall.

Grand County, CO (Zone 5a) Short season
114 days
Last Spring Frost May 28
114 growing days
First Fall Frost September 19
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Grand County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 3
Recommended (50%) ✓ Fits season
Transplant: Jun 18
Safe Start (90%) ✓ Fits season
Transplant: Jul 9

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 Grand County

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

Soil pH

Your soil pH (6.7–8.3) is more alkaline than Raspberries prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Raspberries.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Raspberries.

How to Plant Raspberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 587 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Raspberries

Raspberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Raspberries Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.3" 2" 💧 Light watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Grand County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Raspberries 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.

Raspberries needs ~6,296 GDD — county provides 1,311 GDD May not mature

Raspberries Planting Timeline — Grand County, CO

Raspberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 18 Jun 18 – Jul 2

· 24" apart · Rows 72" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

114 days in Grand County

Growing Tips for Raspberries in Grand County

Direct sow Raspberries outdoors after May 28 in Grand County when soil has warmed and frost danger has passed.

Your 114.0-day growing season in Grand County is tight for Raspberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Grand County receives only 22" of rain annually. Raspberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Provide a trellis for support. Prune summer-bearing types by removing spent canes after harvest. For ever-bearing types, mow all canes in late winter for a single fall crop.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Raspberries in Grand County, CO?

Grand County is in Zone 5a with an average last frost of May 28. Plan your Raspberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grand County, CO?

Grand County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 28 and first fall frost is September 19.

🌱

Your Grand County Garden Planner — Free

A 24-page printable planner built for Grand 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 Grand 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.