Fall is one of the best seasons for growing turnips. Warm late-summer soil encourages quick germination and strong early growth, while cool autumn weather produces smooth, tender roots with a mild, sweet flavor. Unlike spring turnips that may become tough or overly pungent as temperatures rise, fall turnips mature slowly in cooler conditions and develop exceptional quality.

The secret to growing excellent fall turnips is planting according to soil temperature rather than calendar dates. Warm soil helps seeds emerge quickly and allows plants to establish before cold weather arrives. Cool autumn temperatures then improve flavor, texture, and sweetness. This guide explains when to plant, how to grow healthy turnips, and how to harvest both roots and greens.

Best Soil Temperature for Planting

Every vegetable has an ideal soil temperature for germination. Planting within that range produces faster emergence, stronger seedlings, and more dependable harvests.

Turnips are cool-season root crops that germinate quickly and perform best when planted as summer heat begins to decline.

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Ideal soil temperature: 55–70°F (13–21°C)
Minimum soil temperature: about 40°F
Maximum practical soil temperature: about 80°F
Expected germination: 3–7 days

Late-summer soil temperatures are often ideal for starting fall turnips. If soil temperatures remain high:

Water the planting bed before sowing.
Sow in the evening.
Provide temporary shade.
Keep the seedbed evenly moist until emergence.

Projected harvest temperatures

Turnips develop their sweetest, most tender roots when daytime temperatures range between 45° and 65°F (7–18°C) and nighttime temperatures fall between 35° and 50°F (2–10°C).

Light frosts improve flavor by encouraging the roots to store more natural sugars.

Harvest to Table Soil Tip

Soil temperature determines how quickly seeds germinate and roots establish. Air temperature determines the quality of the harvest. That’s why successful fall gardening starts by planting into warm soil and finishes with crops maturing in cool autumn weather.

When to Plant Fall Turnips

For a fall harvest, sow turnips 6 to 8 weeks before your average first fall frost.

Because turnips mature quickly, they are excellent for succession planting.

Sow additional crops every two to three weeks for continuous harvests.

General planting windows:

Northern gardens: July through August
Mid-latitude gardens: August through September
Mild winter climates: September through October

In mild climates, turnips can remain in the ground through winter with mulch protection.

Choose the Right Variety

Turnips are available in both small salad types and larger storage varieties.

Excellent choices include:

Small and Medium Turnips

Tokyo Cross
Hakurei
Purple Top White Globe
White Egg

Storage Turnips

Seven Top
Golden Globe
Gilfeather
Purple Top Milan

Hakurei turnips are especially popular for fall gardens because they produce sweet, tender roots that can be eaten raw.

Prepare the Soil

Turnips grow best in loose, fertile soil.

Before planting:

Loosen soil 8 to 10 inches deep.
Add finished compost.
Remove rocks and compacted areas.
Maintain a soil pH between 6.0 and 7.0.

Avoid fresh manure, which can encourage misshapen roots.

Planting

Sow seeds:

½ inch deep
1 inch apart

Thin seedlings to:

3 to 6 inches apart

Space rows:

12 to 18 inches apart

Thinning is essential because crowded turnips produce small roots.

Water Consistently

Turnips need steady moisture for smooth, tender roots.

Provide approximately 1 inch of water per week.

Uneven moisture can cause:

Woody roots
Splitting
Strong flavor

Mulch helps conserve moisture and maintain stable soil temperatures.

Fertilizing

Turnips are moderate feeders.

If compost was incorporated before planting, additional fertilizer may not be needed.

Avoid excessive nitrogen, which encourages leafy growth at the expense of root development.

Common Problems

Small Roots

Usually caused by:

Crowding
Poor thinning
Compacted soil

Woody Roots

Often caused by:

Hot weather
Drought stress
Delayed harvest

Bitter Flavor

Usually results from warm temperatures or slow growth.

Cabbage Worms

Inspect leaves regularly and remove caterpillars or use Bacillus thuringiensis (Bt) when needed.

Root Maggots

Use crop rotation and floating row covers where this pest is common.

Harvest

Most turnips mature 40 to 60 days after sowing.

Harvest:

Small salad turnips at 30 to 40 days.
Larger roots at 50 to 60 days.

For the best flavor:

Harvest roots when they are 2 to 3 inches across.
Pick greens while young and tender.
Leave mature roots in the ground through cool weather for improved sweetness.

Growing Tips

Sow every two to three weeks for continuous harvests.
Thin seedlings early.
Keep soil consistently moist.
Harvest before roots become oversized.
Use both roots and greens.
Allow cool temperatures to improve sweetness.

My Experience Growing Fall Turnips

I’ve grown turnips in gardens ranging from cold Midwestern climates to mild California winters, and fall remains the ideal season for this crop. The biggest challenge is not growing turnips in cool weather—it is establishing them while late-summer soil is still warm. By planting when soil temperatures are right and maintaining steady moisture, you can achieve fast germination and vigorous growth. Once autumn arrives, cool temperatures transform turnips into one of the sweetest and most rewarding root crops in the garden.

Frequently Asked Questions

What soil temperature is best for planting turnips?

Turnips germinate best when soil temperatures range between 55° and 70°F.

How long do fall turnips take to mature?

Most turnips mature in 40 to 60 days, depending on the variety.

Do turnips become sweeter after frost?

Yes. Cool temperatures encourage turnips to store more sugars, improving flavor.

Can I eat turnip greens?

Yes. Young turnip greens are tender and nutritious. Harvest the outer leaves while allowing roots to continue developing.

How often should turnips be watered?

Provide about 1 inch of water each week while keeping soil evenly moist.

Why are my turnips small?

Small roots are usually caused by crowding, poor soil preparation, or insufficient moisture.

Can turnips survive frost?

Yes. Turnips tolerate light frosts well, and cool weather improves flavor.

Can turnips grow in containers?

Yes. Use containers at least 10 to 12 inches deep with loose, fertile soil.

Fall Garden Planting Calendar

Stage	Best Conditions
Ideal soil temperature for sowing	55–70°F (13–21°C)
Planting window	6–8 weeks before your average first fall frost
Days to maturity	40–60 days (baby turnips in about 30–40 days)
Best harvest temperatures	Days: 45–65°F (7–18°C) • Nights: 35–50°F (2–10°C)
Frost tolerance	Good. Light frosts improve sweetness; roots tolerate colder temperatures with mulch protection.

Tip: Turnips grow quickly when planted into warm soil, but the sweetest roots develop as autumn temperatures cool. Establish plants while the soil is warm, then let cool weather improve flavor and texture.

The Soil Temperature Takeaway

After decades of growing vegetables in different climates, I’ve learned that turnips are a perfect example of why fall gardening works so well. Warm soil gives seeds the quick start they need, while cool autumn temperatures transform ordinary roots into sweet, tender harvests. The best turnips are not rushed—they are planted early enough to establish strong growth and harvested as the weather naturally improves their flavor. Rather than relying on planting dates alone, use soil temperature to know when to plant and air temperature to know when your turnips will reach their finest eating quality.

Plant by soil temperature. Harvest by air temperature.

Continue Growing Your Fall Garden

This article is part of the Harvest to Table Fall Planting Through Harvest Series, a collection of crop-by-crop guides that show you the best soil temperature for planting, the ideal planting window by climate, and the temperatures that produce the highest-quality harvests. If you’re planning an entire fall vegetable garden, start with The Complete Guide to Fall Vegetable Gardening: Planning, Planting, Growing, and Harvesting, then explore the crop guides below for detailed planting and growing advice.

Browse the Series

🥬 Leafy Greens