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When to Plant Turnip in San Juan County, UT

San Juan County, Utah Zone 7a May

Your May game plan for San Juan County, Utah

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 2
Avg. first frost October 11
Soil temp (4") 44°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Collect turnip at their peak

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

Before June arrives, get these ready
  • 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.

San Juan County, Utah is in USDA Zone 7a. The average last spring frost is May 2 and the first fall frost is October 11, giving you a growing season of approximately 162 days.

At an elevation of 5,225 feet, San Juan County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Turnip to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Turnip successfully. Mulch heavily to conserve soil moisture.

San Juan County, UT (Zone 7a) Moderate season
162 days
Last Spring Frost May 2
162 growing days
First Fall Frost October 11
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San Juan County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 1 – Jul 6
Recommended (50%) ✓ Fits season (85 days to spare)
Transplant: May 2 🍅 Harvest: Jun 13 – Jul 18
Safe Start (90%) ✓ Fits season (78 days to spare)
Transplant: May 26 🍅 Harvest: Jul 7 – Aug 11

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 San Juan County

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

Soil pH

Your soil pH (6.5–7.8) is more alkaline than Turnip prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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

4
successive plantings in your 162-day season

Sow every 4.6 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Aug 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,116 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.1" 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" 3.3" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in San Juan 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 ~650 GDD — county provides 2,106 GDD Excellent fit

Turnip Planting Timeline — San Juan County, UT

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 18 Apr 18 – May 9
Harvest May 30 May 30 – Jul 4
Fall Sowing August 2 Aug 2 – Aug 16

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow Harvest
June Harvest
July Harvest
August Fall Sowing
September
October
November
December
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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 7a

📆 Growing Season

162 days in San Juan County

Growing Tips for Turnip in San Juan County

Direct sow Turnip outdoors after May 02 in San Juan County when soil has warmed and frost danger has passed.

Your generous 162.0-day season in San Juan County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.

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

San Juan County receives only 14" 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 San Juan County, UT?

San Juan County is in Zone 7a with an average last frost of May 2. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Juan County, UT?

San Juan County, Utah is in USDA Hardiness Zone 7a. The average last spring frost is May 2 and first fall frost is October 11.

🌱

Your San Juan County Garden Planner — Free

A 24-page printable planner built for San Juan 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.

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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 San Juan County, UT. 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.