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When to Plant Daikon in Columbia County, WA

Daikon is a large, mild Japanese radish that can grow over a foot long. It is excellent for pickling, stir-fries, and as a soil-breaking cover crop.

Columbia County, Washington is in USDA Zone 7a. The average last spring frost is April 28 and the first fall frost is October 11, giving you a growing season of approximately 166 days.

At an elevation of 3,157 feet, Columbia County receives approximately 21.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Daikon during the growing season.

Columbia County, WA (Zone 7a) Moderate season
166 days
Last Spring Frost April 28
166 growing days
First Fall Frost October 11

Columbia County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Monthly Watering Guide for Daikon

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

Month Daikon Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 1.4" 2.9" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 3" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

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

Daikon Planting Timeline — Columbia County, WA

Daikon Planting Calendar

Activity When Date Range
Direct Sow April 14 Apr 14 – May 5
Harvest June 9 Jun 9 – Jul 7
Fall Sowing August 2 Aug 2 – Aug 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.8–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

166 days in Columbia County

Growing Tips for Columbia County

Direct sow in late summer for fall harvest. Loosen soil deeply before planting. Thin seedlings to 6 inches apart. Harvest before hard freeze as exposed shoulders may crack.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Daikon in Columbia County, WA?

Columbia County is in Zone 7a with an average last frost of April 28. Plan your Daikon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Columbia County, WA?

Columbia County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 28 and first fall frost is October 11.

🌱

Your Columbia County Garden Planner — Free

A 22-page printable planner built for Columbia County (Zone 7a). 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 Columbia County, WA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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