Blog

When to Plant Mache in Twisp, WA

Okanogan County, Washington Zone 6b June

Your June gardening checklist

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Okanogan County, Washington.

Avg. last frost May 13
Avg. first frost September 26
Soil temp (4") 57°F
Watering Critical
Pest pressure High
Daylight 15.9 hrs
  1. Sow mache in trays indoors

    These need a head start before your last frost (May 13). Sow into cells now so you're ready to transplant in a few weeks.

  2. It's harvest week for mache

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

July will be here before you know it — start on
  • First harvests: mache
  • Fall sowing: mache

Instant PDF download. No spam, unsubscribe any time.

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.

Twisp, Washington is in USDA Zone 6b. The average last spring frost is May 13 and the first fall frost is September 26, giving you a growing season of approximately 136 days.

At an elevation of 3,788 feet, Okanogan County receives approximately 21.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Mache to ensure they mature before fall.

Twisp, WA (Zone 6b) Short season
136 days
Last Spring Frost May 13
136 growing days
First Fall Frost September 26

Twisp Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Mache Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 19 – Jul 24
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 24 – Jul 29
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Jul 18 – Aug 22

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 Twisp

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

Soil pH

Your soil pH (5.4–6.5) is more acidic than Mache prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Mache.

Organic Matter

Organic matter is excellent (5.6%) — Mache will thrive.

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

4
successive plantings in your 136-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
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 777 gal / 100 sq ft

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 2.9" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 0.7" 3.6" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.7" 3.6" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 3.6" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Okanogan 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 ~612 GDD — county provides 1,666 GDD Excellent fit

Mache Planting Timeline — Twisp, WA

Mache Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 13 May 13 – May 27
Direct Sow April 29 Apr 29 – May 20
Harvest June 24 Jun 24 – Jul 29
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: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

136 days in Okanogan County

Growing Tips for Mache in Twisp

Direct sow Mache outdoors after May 13 in Okanogan County when soil has warmed and frost danger has passed.

Okanogan County receives only 21" 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 →

🌱

Your Okanogan County Garden Planner — Free

A 22-page printable planner built for Okanogan County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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