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When to plant Grapes in Summit County, CO

Summit County's short 80-day growing season means one Grapes planting between July 7 and July 21. No fall crop in Zone 5a.

When to Plant Grapes in Summit County, CO

Grapes
Summit County, Colorado Zone 5a July

Your July planting checklist for Summit County, Colorado

Your Summit County, Colorado garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost June 16
Avg. first frost September 4
Soil temp (4") 51°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Time to transplant grapes

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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Grapes are vigorous climbing vines producing clusters of sweet or wine-quality fruits. They require training on a trellis or arbor and annual pruning for best production.

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 Grapes to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Grapes successfully. Mulch heavily to conserve soil moisture.

Summit County, CO (Zone 5a) Very short season
80 days
Last Spring Frost June 16
80 growing days
First Fall Frost September 4

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Grapes Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jul 1
Recommended (50%) ✓ Fits season
Transplant: Jul 7
Safe Start (90%) ✓ Fits season
Transplant: Jul 17

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 Grapes's growing requirements.

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Grapes prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Grapes.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Grapes.

How to Plant Grapes

72"
Between Plants
96"
Between Rows

Grapes Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Grapes

Grapes needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Grapes 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 3" 1.3" 1.7" 🚿 Regular watering
Jul 3" 1.5" 1.5" 🚿 Regular watering
Aug 3" 1.9" 1.1" 💧 Light watering
Sep 3" 1.3" 1.7" 🚿 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.

Grapes 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.

Grapes needs ~9,809 GDD — county provides 860 GDD May not mature

Grapes Planting Timeline — Summit County, CO

Grapes Planting Calendar

Activity When Date Range
Transplant Outdoors July 7 Jul 7 – Jul 21

· 72" apart · Rows 96" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

730–1095 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 Grapes in Summit County

Direct sow Grapes 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 Grapes (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Provide a strong trellis system. Prune heavily in late winter while dormant. Thin fruit clusters for larger berries. Good air circulation prevents fungal diseases.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Radish

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Grapes in Summit County, CO?

Summit County is in Zone 5a with an average last frost of June 16. Plan your Grapes 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 Grapes in Summit County, CO?

In Summit County, CO, plant Grapes 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 Grapes?

Summit County sits in USDA Zone 5a. Grapes grows reliably in zones 4a through 10b, so it's a good fit here.

Can Grapes grow in Summit County's climate?

Yes — Grapes 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.

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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 Summit County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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