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When to plant Blackberries in Custer County, CO

Plant Blackberries in Custer County during the brief June 13–June 27 window. With 125 frost-free days, fall plantings can't mature before September 25.

When to Plant Blackberries in Custer County, CO

Blackberries

Blackberries are vigorous bramble fruits that produce sweet-tart berries on thorny or thornless canes. They are prolific producers and relatively low-maintenance once established.

Custer County, Colorado is in USDA Zone 5b. The average last spring frost is May 23 and the first fall frost is September 25, giving you a growing season of approximately 125 days.

At an elevation of 8,115 feet, Custer County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Blackberries during the growing season. With low rainfall, drip irrigation is essential for growing Blackberries successfully. Mulch heavily to conserve soil moisture.

Custer County, CO (Zone 5b) Short season
125 days
Last Spring Frost May 23
125 growing days
First Fall Frost September 25

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Monthly Watering Guide for Blackberries

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

Month Blackberries Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

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

Blackberries Planting Timeline — Custer County, CO

Blackberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 13 Jun 13 – Jun 27

· 24" apart · Rows 72" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

125 days in Custer County

Growing Tips for Custer County

Plant bare-root canes in spring. Provide a sturdy trellis system. Prune out spent fruiting canes after harvest. New canes fruit in their second year (floricanes).

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Blackberries in Custer County, CO?

Custer County is in Zone 5b with an average last frost of May 23. Plan your Blackberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, CO?

Custer County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 23 and first fall frost is September 25.

When should I plant Blackberries in Custer County, CO?

In Custer County, CO, plant Blackberries after the last frost (around May 23) and before the first frost (around September 25). Best results when soil holds above 50°F.

What growing zone is Custer County, CO for Blackberries?

Custer County sits in USDA Zone 5b. Blackberries grows reliably in zones 5a through 10b, so it's a good fit here.

Can Blackberries grow in Custer County's climate?

Yes — Blackberries grows well in Custer County's temperate climate. Custer County averages a 125-day frost-free season, with last frost around May 23 and first frost around September 25.

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Your Custer County Garden Planner — Free

A 22-page printable planner built for Custer 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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