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When to plant Mache in Denver County, CO

Plant Mache in Denver County from April 30 to May 21 in spring. Denver County sits in USDA Zone 6a, with last frost around May 14 and first frost on September 26. A second sowing from July 18 to August 1 extends the harvest into fall.

When to Plant Mache in Denver County, CO

Denver County, Colorado Zone 6a July

Your July planting checklist for Denver County, Colorado

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Denver County, Colorado.

Avg. last frost May 14
Avg. first frost September 26
Soil temp (4") 57°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Harvest mache as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

  2. Direct-sow mache for cool weather

    Keep young seedlings shaded and moist in summer heat. A row of taller crops works as natural shade.

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Mache (corn salad) is a cold-hardy salad green with small, rounded, tender leaves and a mild, nutty flavor. It thrives in cool weather and even overwinters in many climates.

Denver County, Colorado is in USDA Zone 6a. 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 85°F, providing good warmth for Mache during the growing season.

Denver County, CO (Zone 6a) 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

Mache Planting Risk Windows

Early Start (70% safe) ✓ Fits season (63 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 14 – Jul 19
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jun 25 – Jul 30
Safe Start (90%) ✓ Fits season (51 days to spare)
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Jul 22 – Aug 26

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 Mache's growing requirements.

Soil pH

Your soil pH (6.4–7.8) overlaps with Mache's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Mache

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Mache

3
successive plantings in your 135-day season

Sow every 4.6 weeks. Last sowing by Jul 28 to harvest before frost.

For a dedicated fall crop, sow by Jul 18.

Mache Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 522 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Mache

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

Month Mache Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Mache 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.

Mache needs ~688 GDD — county provides 1,856 GDD Excellent fit

Mache Planting Timeline — Denver County, CO

Mache Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 14 May 14 – May 28
Direct Sow April 30 Apr 30 – May 21
Harvest June 25 Jun 25 – Jul 30
Fall Sowing July 18 Jul 18 – Aug 1

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Denver County

Growing Tips for Mache in Denver County

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

Denver County receives only 20" of rain annually. Mache needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in early spring or late summer for fall and winter harvest. Seeds need light to germinate so press gently into soil surface. Harvest whole rosettes.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mache in Denver County, CO?

Denver County is in Zone 6a with an average last frost of May 14. Plan your Mache planting based on this frost date — see the calendar above for exact timing.

What planting zone is Denver County, CO?

Denver County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.

When should I plant Mache in Denver County, CO?

In Denver County, CO, plant Mache after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.

What growing zone is Denver County, CO for Mache?

Denver County sits in USDA Zone 6a. Mache grows reliably in zones 2a through 10b, so it's a good fit here.

Can Mache grow in Denver County's climate?

Yes — Mache grows well in Denver County's temperate climate. Denver County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.

🌱

Your Denver County Garden Planner — Free

A 22-page printable planner built for Denver County (Zone 6a). 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 Denver 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.