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When to Plant Chives in Denver County, CO

Chives are a hardy perennial herb with a mild onion flavor and attractive purple pom-pom flowers. They are one of the easiest herbs to grow and maintain.

Denver County, Colorado is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 6,818 feet, Denver County receives approximately 20.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Chives during the growing season.

Denver County, CO (Zone 5b) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Denver County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (0 days to spare)
Transplant: May 10 🍅 Harvest: Jul 12 – Sep 20
Recommended (50%) ✗ May not fit
Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Safe Start (90%) ✗ May not fit
Transplant: Jun 17 🍅 Harvest: Aug 19 – Oct 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 Denver County

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

Soil pH

Your soil pH (6.4โ€“7.8) is more alkaline than Chives prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Chives

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Chives

2
successive plantings in your 135-day season

Sow every 6.9 weeks. Last sowing by Jun 28 to harvest before frost.

Plant Water Budget

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

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Chives

Chives needs approximately 0.4 inches of water per week (1.7" per month). Here's how your county's rainfall compares month by month.

Month Chives Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 1.7" 2.3" 0" โœ… Rainfall sufficient
Jun 1.7" 1.3" 0.4" ๐Ÿ’ง Light watering
Jul 1.7" 1.8" 0" โœ… Rainfall sufficient
Aug 1.7" 2.1" 0" โœ… Rainfall sufficient
Sep 1.7" 1.8" 0" โœ… Rainfall sufficient
Oct โ€” 1.8" 0" โ„๏ธ Dormant
Nov โ€” 1.6" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

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

Chives 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.

Chives needs ~1,031 GDD — county provides 1,856 GDD Excellent fit

Chives Planting Timeline โ€” Denver County, CO

Chives Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 โ€“ Jun 4
Harvest July 23 Jul 23 โ€“ Oct 1

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.4"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

135 days in Denver County

Growing Tips for Chives in Denver County

Direct sow Chives outdoors after May 14 in Denver County when soil has warmed and frost danger has passed.

Common pests for Chives in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start from seed or divisions in spring. Cut back to 2 inches after flowering to encourage fresh growth. Both the leaves and flowers are edible and delicious.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chives in Denver County, CO?

Denver County is in Zone 5b with an average last frost of May 14. Plan your Chives planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Denver County, CO?

Denver County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Denver County gardeners in Zone 5b 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 Denver County, CO. Local conditions may vary. Last updated: April 2026.