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When to Plant Turnip in Latah County, ID

Latah County, Idaho Zone 6b May

This month in Latah County, Idaho

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 11
Avg. first frost September 23
Soil temp (4") 41°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
A few tasks this May that'll pay off in June
  • First harvests: turnip

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Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

Latah County, Idaho is in USDA Zone 6b. The average last spring frost is May 11 and the first fall frost is September 23, giving you a growing season of approximately 135 days.

At an elevation of 5,530 feet, Latah County receives approximately 14.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Turnip during the growing season. With low rainfall, drip irrigation is essential for growing Turnip successfully. Mulch heavily to conserve soil moisture.

Latah County, ID (Zone 6b) Short season
135 days
Last Spring Frost May 11
135 growing days
First Fall Frost September 23

Latah County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Transplant: May 4 🍅 Harvest: Jun 15 – Jul 20
Recommended (50%) ✓ Fits season (58 days to spare)
Transplant: May 11 🍅 Harvest: Jun 22 – Jul 27
Safe Start (90%) ✓ Fits season (55 days to spare)
Transplant: Jun 5 🍅 Harvest: Jul 17 – Aug 21

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 Latah County

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

Soil pH

Your soil pH (6.7–8.0) is more alkaline than Turnip prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Turnip.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Turnip.

How to Plant Turnip

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Turnip

3
successive plantings in your 135-day season

Sow every 4.6 weeks. Last sowing by Jul 25 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,210 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Turnip

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

Month Turnip Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Turnip 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.

Turnip needs ~725 GDD — county provides 1,957 GDD Excellent fit

Turnip Planting Timeline — Latah County, ID

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 27 Apr 27 – May 18
Harvest June 8 Jun 8 – Jul 13
Fall Sowing July 15 Jul 15 – Jul 29

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

135 days in Latah County

Growing Tips for Turnip in Latah County

Direct sow Turnip outdoors after May 11 in Latah County when soil has warmed and frost danger has passed.

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

Latah County receives only 15" of rain annually. Turnip 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. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turnip in Latah County, ID?

Latah County is in Zone 6b with an average last frost of May 11. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Latah County, ID?

Latah County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 11 and first fall frost is September 23.

🌱

Your Latah County Garden Planner — Free

A 24-page printable planner built for Latah 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.

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

Sources & credits

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