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When to plant Kai Lan in Mills County, IA

Mills County gardeners should plant Kai Lan between April 12 and May 3 in spring. With Mills County's Zone 5b climate (last frost April 26), Kai Lan needs 45–60 days to mature — plant by August 8 for a full harvest. A second sowing from July 29 to August 12 extends the harvest into fall.

When to Plant Kai Lan in Mills County, IA

Kai lan (Chinese broccoli) is a brassica grown for its thick, glossy stems and small flower buds. It has a slightly bitter, broccoli-like flavor essential in Cantonese cooking.

Mills County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 7, giving you a growing season of approximately 164 days.

At an elevation of 1,355 feet, Mills County receives approximately 35.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Kai Lan during the growing season.

Mills County, IA (Zone 5b) Moderate season
164 days
Last Spring Frost April 26
164 growing days
First Fall Frost October 7

Mills County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Kai Lan Planting Timeline — Mills County, IA

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 12 Apr 12 – May 3
Harvest June 14 Jun 14 – Jul 12
Fall Sowing July 29 Jul 29 – Aug 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

164 days in Mills County

Growing Tips for Mills County

Direct sow in spring or fall. Harvest when flower buds first appear but before they open. Cut stems at the base to encourage side shoots. Prefers cool weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kai Lan in Mills County, IA?

Mills County is in Zone 5b with an average last frost of April 26. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mills County, IA?

Mills County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 7.

When should I plant Kai Lan in Mills County, IA?

In Mills County, IA, plant Kai Lan after the last frost (around April 26) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Mills County, IA for Kai Lan?

Mills County sits in USDA Zone 5b. Kai Lan grows reliably in zones 2a through 11b, so it's a good fit here.

Can Kai Lan grow in Mills County's climate?

Yes — Kai Lan grows well in Mills County's temperate climate. Mills County averages a 164-day frost-free season, with last frost around April 26 and first frost around October 7.

🌱

Your Mills County Garden Planner — Free

A 22-page printable planner built for Mills 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.

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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 Mills County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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