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When to Plant Tatsoi in Davis County, IA

Davis County, Iowa Zone 5b May

Your May gardening checklist

Your garden in Davis County, Iowa is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 19
Avg. first frost October 16
Soil temp (4") 60°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Fire up the seed-starting tray: tatsoi

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Harvest tatsoi as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Coming up in June — start thinking about
  • First harvests: tatsoi

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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.

Davis County, Iowa is in USDA Zone 5b. The average last spring frost is April 19 and the first fall frost is October 16, giving you a growing season of approximately 180 days.

At an elevation of 859 feet, Davis County receives approximately 30.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Tatsoi during the growing season.

Davis County, IA (Zone 5b) Moderate season
180 days
Last Spring Frost April 19
180 growing days
First Fall Frost October 16
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Davis County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (110 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: May 18 – Jun 22
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 24 – Jun 28
Safe Start (90%) ✓ Fits season (108 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 7 – Jul 12

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 Davis County

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

Soil pH

Your soil pH (6.2–6.7) is within Tatsoi's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Tatsoi will thrive.

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

6
successive plantings in your 180-day season

Sow every 4 weeks. Last sowing by Aug 27 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 469 gal / 100 sq ft

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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Davis 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 2,475 GDD Excellent fit

Tatsoi Planting Timeline — Davis County, IA

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 5 Apr 5 – Apr 26
Harvest May 24 May 24 – Jun 28
Fall Sowing August 7 Aug 7 – Aug 21

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

180 days in Davis County

Growing Tips for Tatsoi in Davis County

Direct sow Tatsoi outdoors after April 19 in Davis County when soil has warmed and frost danger has passed.

Your generous 180.0-day season in Davis 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.

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 Davis County, IA?

Davis County is in Zone 5b with an average last frost of April 19. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Davis County, IA?

Davis County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 19 and first fall frost is October 16.

🌱

Your Davis County Garden Planner — Free

A 24-page printable planner built for Davis County (Zone 5b). 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 Davis County, IA. 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.