Wisconsin’s short growing season means turnips should go into the ground as soon as the soil can be worked. Finding the best time to plant turnip in wisconsin is key to getting a good harvest before frost hits. Turnips are a cool-season crop that actually tastes better after a light frost, so timing matters a lot.
You can plant turnips in both spring and late summer in Wisconsin. The trick is to avoid the hottest part of summer, which makes turnips woody and bitter. This guide covers everything you need to know about planting turnips in Wisconsin, from soil temps to fall harvest dates.
Best Time To Plant Turnip In Wisconsin
The best time to plant turnip in wisconsin is early spring, as soon as the soil can be worked, usually from mid-April to early May. For a fall crop, plant in late July to mid-August. Turnips grow best when temperatures are between 40°F and 75°F.
Wisconsin is split into USDA hardiness zones 3 through 5. Northern areas like Ashland and Superior have shorter seasons. Southern areas like Madison and Milwaukee get a bit more warmth. Your exact planting window depends on your local frost dates.
Spring Planting Window For Wisconsin Turnips
Spring planting gives you turnips for early summer eating. You want to get seeds in the ground about 2 to 4 weeks before your last expected spring frost. In southern Wisconsin, that’s around mid-April. In the north, wait until early May.
Check your soil temperature with a simple thermometer. Turnip seeds germinate best when soil is at least 40°F. If the ground is still frozen or waterlogged, wait a few days. Turnips don’t like wet feet.
- Southern Wisconsin: Plant April 10 to April 30
- Central Wisconsin: Plant April 20 to May 10
- Northern Wisconsin: Plant May 1 to May 20
You can also plant a second spring crop in late May for a continuous harvest. Just make sure you have enough time before summer heat sets in. Turnips stop growing well when temps hit 80°F.
Fall Planting Window For Wisconsin Turnips
Fall turnips are actually sweeter than spring turnips. The cold weather converts starches to sugar. For a fall harvest, plant about 60 to 70 days before your first expected fall frost. In Wisconsin, that’s usually late July to mid-August.
First frost dates in Wisconsin range from mid-September in the north to early October in the south. Count back 60 days from your frost date to find your planting window. Turnips can handle a light frost, so you don’t need to rush.
- Find your first fall frost date (check local almanac or extension office)
- Subtract 65 days (average turnip maturity)
- Plant seeds on that date or a few days earlier
For example, if your first frost is October 1, plant fall turnips around July 25. If you live in northern Wisconsin where frost comes in mid-September, plant by mid-July.
Soil Preparation For Wisconsin Turnips
Turnips grow best in loose, well-drained soil with a pH between 6.0 and 7.5. Wisconsin soil is often heavy clay or sandy. You can amend it with compost or aged manure a few weeks before planting.
Remove rocks and break up large clumps. Turnip roots need room to swell. If the soil is too hard, roots will be misshapen or stunted. A raised bed works great for turnips.
Testing Your Soil
Get a simple soil test kit from a garden center or your local UW Extension office. Turnips need moderate nitrogen but lots of phosphorus and potassium. Too much nitrogen makes big leaves but small roots.
If your soil is low in phosphorus, add bone meal or rock phosphate. For potassium, use greensand or wood ash. Follow the test results exactly. Over-fertilizing can hurt root development.
Amending Clay Soil
Wisconsin clay soil is common in many areas. It holds water and gets hard when dry. Mix in 2 to 3 inches of compost or well-rotted manure. This improves drainage and makes soil easier for roots to push through.
You can also add sand or perlite to lighten clay. But compost is usually enough. Turnips don’t need perfect soil, just loose enough for roots to grow straight.
How To Plant Turnip Seeds In Wisconsin
Turnip seeds are tiny. Sow them directly in the garden about 1/4 to 1/2 inch deep. Space seeds about 1 inch apart in rows that are 12 to 18 inches apart. Cover lightly with soil and water gently.
Seeds germinate in 7 to 14 days, depending on soil temperature. In cool Wisconsin springs, it might take a bit longer. Keep the soil moist but not soaked during germination.
Thinning Seedlings
Once seedlings have 2 to 3 true leaves, thin them to 4 to 6 inches apart. Crowded turnips produce small, tough roots. You can eat the thinnings in salads or stir-fries.
Thin carefully so you don’t disturb nearby roots. Use scissors to cut unwanted seedlings at soil level. Pulling them can damage the roots you want to keep.
Succession Planting
To have a steady supply of turnips, plant a new row every 2 to 3 weeks. This works well in spring and again in late summer. Just stop planting about 60 days before your first fall frost.
In Wisconsin, you can get 3 to 4 succession plantings in spring. For fall, you might only get 1 or 2 plantings before frost. That’s fine because fall turnips store well.
Watering And Care For Wisconsin Turnips
Turnips need consistent moisture, about 1 inch of water per week. In Wisconsin’s variable weather, you might need to supplement during dry spells. Drip irrigation or soaker hoses work best.
Mulch around plants with straw or grass clippings. This keeps soil cool and moist, which turnips love. Mulch also suppresses weeds that compete for nutrients.
Fertilizing Turnips
Turnips are light feeders. If you added compost before planting, you probably don’t need more fertilizer. If leaves look pale, side-dress with a balanced fertilizer like 10-10-10 at half strength.
Avoid high-nitrogen fertilizers. They cause lush leaf growth at the expense of roots. Too much nitrogen also makes roots split or become hairy.
Pest And Disease Management
Common turnip pests in Wisconsin include flea beetles, aphids, and root maggots. Flea beetles leave small holes in leaves. Use row covers to protect young plants. Floating row covers work great.
Root maggots are worse in cool, wet springs. Rotate your turnip crop every year. Don’t plant turnips where other brassicas (cabbage, broccoli) grew the previous year.
Diseases like clubroot and downy mildew can occur. Clubroot causes swollen, distorted roots. It’s more common in acidic soil. Keep pH above 6.5 to reduce risk.
Harvesting Turnips In Wisconsin
Spring turnips are ready in 30 to 60 days, depending on variety. Harvest when roots are 2 to 3 inches in diameter. Larger roots get woody and strong-flavored.
Fall turnips can be left in the ground longer. They actually improve after a light frost. Harvest before the ground freezes hard. In Wisconsin, that’s usually late October to early November.
How To Harvest
Loosen soil around the root with a garden fork. Grasp the greens near the base and pull gently. If the root resists, loosen more soil. Damaged roots don’t store well.
Cut off the greens about 1 inch above the root. Greens are edible and nutritious. Wash them well and use within a few days. Roots can be stored for months.
Storing Turnips
Store turnips in a cool, humid place like a root cellar or refrigerator. Ideal temperature is 32°F to 40°F with high humidity. They keep for 2 to 4 months under good conditions.
Don’t wash roots before storage. Brush off excess soil and place in perforated plastic bags. Check regularly for soft spots or mold. Remove any bad ones to prevent spread.
Best Turnip Varieties For Wisconsin
Choose varieties that mature quickly and handle cool weather. Wisconsin’s short season favors fast-growing types. Here are some reliable choices.
- Purple Top White Globe: Classic variety, matures in 50 days
- Tokyo Cross: Hybrid, very fast at 35 days
- White Lady: Smooth roots, 45 days
- Golden Ball: Yellow flesh, 60 days
- Hakurei: Japanese salad turnip, 38 days
Hakurei turnips are especially good for spring planting. They are sweet and tender even when larger. Tokyo Cross is great for fall because it matures fast before frost.
Specialty Turnips
Some turnips are grown mainly for their greens. Seven Top is a variety that produces lots of leaves but small roots. Shogoin is another greens variety. Plant these if you prefer turnip greens over roots.
For storage, choose Purple Top White Globe or Golden Ball. These varieties hold up well in cold storage. They are also more disease-resistant than some newer hybrids.
Common Mistakes When Planting Turnips In Wisconsin
Many gardeners plant turnips too late in spring. If you wait until May in southern Wisconsin, the roots may not mature before summer heat. Heat causes bolting and bitterness.
Another mistake is planting too deep. Turnip seeds need light to germinate. Cover them with just a thin layer of soil. Deep planting leads to poor germination.
Overcrowding is a big problem. Thin seedlings ruthlessly. Even if it feels wasteful, giving each root space is essential. Crowded turnips are small and tough.
Ignoring Soil Temperature
Planting in cold, wet soil causes seeds to rot. Wait until soil is at least 40°F. Use a soil thermometer for accuracy. Guessing often leads to failure.
If you plant too early and a late frost hits, young seedlings may die. Have row covers ready to protect them. A light frost is okay, but hard freeze kills tender plants.
Forgetting To Water
Turnips need even moisture. If soil dries out, roots become tough and bitter. In Wisconsin’s dry spells, water deeply once a week. Shallow watering encourages shallow roots.
Mulch helps retain moisture. Without mulch, you might need to water every 3 to 4 days in hot weather. Check soil moisture by sticking your finger an inch deep.
Frequently Asked Questions
Can I plant turnips in July in Wisconsin?
Yes, July is perfect for fall turnips. Plant in late July to mid-August for a harvest before hard frost. Northern Wisconsin should plant earlier in July.
How late can I plant turnips in Wisconsin?
You can plant as late as mid-August in southern Wisconsin. In northern areas, plant by early August. Count back 60 days from your first frost date.
Do turnips need full sun in Wisconsin?
Turnips grow best in full sun, at least 6 hours per day. They can tolerate partial shade but roots will be smaller. Full sun produces the best yields.
What is the best turnip variety for Wisconsin fall planting?
Tokyo Cross and Purple Top White Globe are excellent for fall. They mature quickly and handle frost well. Hakurei is also good but less cold-hardy.
Can I grow turnips in containers in Wisconsin?
Yes, use containers at least 12 inches deep. Choose smaller varieties like Hakurei. Containers warm up faster in spring, so you can plant a bit earlier.
Final Tips For Wisconsin Turnip Growers
Start your spring turnips as soon as the soil is workable. Don’t wait for perfect weather. Turnips are tough and can handle a little cold. Just protect them from hard freezes.
For fall turnips, plant in late July or early August. They will taste sweeter after frost. Harvest before the ground freezes solid. Store in a cool, dark place.
Rotate your turnip crop each year to prevent soil-borne diseases. Don’t plant them where other brassicas grew recently. A 3-year rotation is ideal.
Experiment with different varieties. Each year you’ll learn what works best in your microclimate. Wisconsin’s diverse regions mean local conditions vary a lot.
Turnips are one of the easiest crops to grow in Wisconsin. With proper timing, you can enjoy fresh turnips from spring through fall. Follow these guidelines and you’ll have a bountiful harvest.