When to plant Boysenberries in Summit County, CO
Summit County sits in cold Zone 5a. Plant Boysenberries July 7–July 21 for the single annual harvest; the September 4 first frost closes the window.
When to Plant Boysenberries in Summit County, CO
Your June gardening checklist
A quick June briefing for Summit County, Colorado gardeners — what's urgent, what's next, and what can wait.
Get ahead of July
- Transplants going out: boysenberries
Boysenberries are a cross between raspberries, blackberries, and loganberries, producing large, dark, intensely flavored berries. They are excellent for jams and pies.
Summit County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.
At an elevation of 7,005 feet, Summit County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Boysenberries to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Boysenberries successfully. Mulch heavily to conserve soil moisture.
Summit County Soil Profile
Soil Type
Loam
Soil pH
6.8-8
Drainage
Well Drained
Boysenberries 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 Summit County
How your county's soil matches Boysenberries's growing requirements.
Soil pH
Your soil pH (6.8–8.0) is more alkaline than Boysenberries prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Summit County is excellent for Boysenberries — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Boysenberries.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Boysenberries.
How to Plant Boysenberries
Boysenberries Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Boysenberries
Boysenberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Boysenberries Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | — | 1.8" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Summit County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Boysenberries 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.
Boysenberries Planting Timeline — Summit County, CO
Boysenberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | July 7 | Jul 7 – Jul 21 |
· 24" apart · Rows 72" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | Transplant Outdoors |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
365–730 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
80 days in Summit County
Growing Tips for Boysenberries in Summit County
Direct sow Boysenberries outdoors after June 16 in Summit County when soil has warmed and frost danger has passed.
Your 80.0-day growing season in Summit County is tight for Boysenberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.
Summit County receives only 18" of rain annually. Boysenberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Provide strong trellising for vigorous canes. Prune spent canes to ground after harvest. Mulch heavily to retain moisture. Protect from wind to prevent cane damage.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Boysenberries in Other Locations
Frequently Asked Questions
When should I plant Boysenberries in Summit County, CO?
Summit County is in Zone 5a with an average last frost of June 16. Plan your Boysenberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Summit County, CO?
Summit County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 4.
When should I plant Boysenberries in Summit County, CO?
In Summit County, CO, plant Boysenberries after the last frost (around June 16) and before the first frost (around September 4). Best results when soil holds above 50°F.
What growing zone is Summit County, CO for Boysenberries?
Summit County sits in USDA Zone 5a. Boysenberries grows reliably in zones 5a through 10b, so it's a good fit here.
Can Boysenberries grow in Summit County's climate?
Yes — Boysenberries grows well in Summit County's temperate climate. Summit County averages a 80-day frost-free season, with last frost around June 16 and first frost around September 4.
Your Summit County Garden Planner — Free
A 22-page printable planner built for Summit 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.