Blog

When to Plant Tatsoi in Adams County, ID

Adams County, Idaho Zone 6a May

Your May planting checklist for Adams County, Idaho

May is a pivotal month for Adams County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 20
Avg. first frost September 25
Soil temp (4") 39°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Transplant tatsoi outside

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Outdoor sowing time: tatsoi

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

Looking ahead to June
  • Starting indoors: tatsoi
  • First harvests: tatsoi

Instant PDF download. No spam, unsubscribe any time.

Tatsoi is a compact Asian green forming beautiful rosettes of dark, spoon-shaped leaves with a mild mustard flavor. It is extremely cold-hardy and versatile.

Adams County, Idaho is in USDA Zone 6a. The average last spring frost is May 20 and the first fall frost is September 25, giving you a growing season of approximately 128 days.

At an elevation of 6,593 feet, Adams County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Tatsoi during the growing season.

Adams County, ID (Zone 6a) Short season
128 days
Last Spring Frost May 20
128 growing days
First Fall Frost September 25
Share this guide:

Adams County Soil Profile

Soil Type

Loam

Soil pH

6.3-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Jul 14
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jun 24 – Jul 29
Safe Start (90%) ✓ Fits season (54 days to spare)
Start indoors: May 19 Transplant: Jun 23 🍅 Harvest: Jul 28 – Sep 1

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 Adams County

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

Soil pH

Your soil pH (6.3–8.0) overlaps with Tatsoi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Tatsoi.

Organic Matter

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

How to Plant Tatsoi

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 Tatsoi

4
successive plantings in your 128-day season

Sow every 4 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Jul 17.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 853 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Tatsoi

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

Month Tatsoi Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Tatsoi 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.

Tatsoi needs ~584 GDD — county provides 1,760 GDD Excellent fit

Tatsoi Planting Timeline — Adams County, ID

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 6 May 6 – May 27
Harvest June 24 Jun 24 – Jul 29
Fall Sowing July 17 Jul 17 – Jul 31

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

128 days in Adams County

Growing Tips for Tatsoi in Adams County

Direct sow Tatsoi outdoors after May 20 in Adams County when soil has warmed and frost danger has passed.

Your generous 128.0-day season in Adams County allows multiple plantings of Tatsoi. Sow every 17.0 days for continuous harvest.

Common pests for Tatsoi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Adams County receives only 21" of rain annually. Tatsoi needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in spring or fall. Tatsoi tolerates frost down to 15F. Harvest outer leaves or cut whole rosettes. Excellent in salads, stir-fries, or lightly wilted.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tatsoi in Adams County, ID?

Adams County is in Zone 6a with an average last frost of May 20. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, ID?

Adams County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 20 and first fall frost is September 25.

🌱

Your Adams County Garden Planner — Free

A 24-page printable planner built for Adams 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.

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 Adams County, ID. Local conditions may vary. Last updated: May 2026.

Sources & credits

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