Blog

When to Plant Tomatoes in Eagle County, CO

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Eagle County, Colorado is in USDA Zone 4b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,116 feet, Eagle County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Tomatoes to ensure they mature before fall.

Eagle County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Eagle County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 3 Transplant: Jun 26 🍅 Harvest: Aug 28 – Nov 6
Recommended (50%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jul 7 🍅 Harvest: Sep 8 – Nov 17
Safe Start (90%) ✗ May not fit
Start indoors: Apr 25 Transplant: Jul 18 🍅 Harvest: Sep 19 – Nov 28

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 Eagle County

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

Soil pH

Your soil pH (6.6โ€“7.7) is more alkaline than Tomatoes prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Eagle County is excellent for Tomatoes โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

How Much Tomatoes to Grow

10-15 lbs
Average yield per plant
3
Plants per person
18 sq ft
Space per person

For a family of 4, plant approximately 12 tomatoes plants in about 72 sq ft. In Eagle County's 83-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Plant Water Budget

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

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan โ€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 2.8" 0" โ„๏ธ Dormant
May โ€” 3.2" 0" โ„๏ธ Dormant
Jun 5.2" 1.6" 3.6" ๐Ÿšฟ Regular watering
Jul 5.2" 2.1" 3.1" ๐Ÿšฟ Regular watering
Aug 5.2" 2.4" 2.8" ๐Ÿšฟ Regular watering
Sep 5.2" 1.8" 3.4" ๐Ÿšฟ Regular watering
Oct โ€” 2" 0" โ„๏ธ Dormant
Nov โ€” 1.6" 0" โ„๏ธ Dormant
Dec โ€” 1.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Eagle County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Tomatoes 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" โ€” every day above 50ยฐF 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.

Tomatoes needs ~779 GDD — county provides 892 GDD Good fit

Tomatoes Planting Timeline โ€” Eagle County, CO

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 โ€“ Apr 28
Transplant Outdoors July 7 Jul 7 โ€“ Jul 21
Direct Sow June 30 Jun 30 โ€“ Jul 21
Harvest September 8 Sep 8 โ€“ Nov 17

Plant 0.5" deep ยท 24" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May โ€”
June Direct Sow
July Transplant Outdoors Direct Sow
August โ€”
September Harvest
October Harvest
November Harvest
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

83 days in Eagle County

Growing Tips for Tomatoes in Eagle County

Direct sow Tomatoes outdoors after June 16 in Eagle County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Eagle County is tight for Tomatoes (60.0-85.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

Eagle County receives only 24" of rain annually. Tomatoes needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for Eagle County

Choose determinate, early-maturing varieties for your short season

Early Girl (52d) Stupice (55d) Glacier (55d) Sub Arctic Plenty (45d)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35ยฐF, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Eagle County, CO?

Eagle County is in Zone 4b with an average last frost of June 16. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Eagle County, CO?

Eagle County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Eagle County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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