Wisconsin’s cold climate means rutabaga seeds should go into the ground in mid-summer for a fall harvest. The best time to plant rutabaga in wisconsin is typically between late June and mid-July, depending on your specific region within the state. This timing ensures the roots mature during the cool autumn weather, which gives them that sweet, nutty flavor Wisconsin gardeners love.
Rutabagas are a root vegetable that thrives in cooler temperatures. They need about 90 to 110 days to reach full size, so planning your planting window is key. In Wisconsin, the first frost usually arrives between late September and early October, depending on where you live. By planting in mid-summer, you give the rutabagas enough time to grow before the ground freezes.
Let’s break down exactly when and how to plant rutabagas in Wisconsin for the best results. This guide covers everything from soil prep to harvesting, so you can enjoy a bountiful fall crop.
Best Time To Plant Rutabaga In Wisconsin
The exact planting date depends on your location within Wisconsin. The state has three main growing zones: the northern region (Zone 3-4), central region (Zone 4-5), and southern region (Zone 5-6). Each zone has slightly different frost dates.
Here’s a quick breakdown by region:
- Northern Wisconsin (near Superior, Rhinelander): Plant from June 20 to July 5. First frost typically arrives around September 15-25.
- Central Wisconsin (Wausau, Stevens Point): Plant from June 25 to July 10. First frost usually hits around September 25 to October 5.
- Southern Wisconsin (Madison, Milwaukee): Plant from July 1 to July 15. First frost typically arrives around October 5-15.
If you plant too early, the roots may become woody or bolt (go to seed) in the summer heat. If you plant too late, they won’t have enough time to mature before the ground freezes. The sweet spot is about 10-12 weeks before your first expected frost date.
Why Mid-Summer Planting Works Best
Rutabagas are a cool-season crop. They germinate best when soil temperatures are between 50°F and 75°F. In Wisconsin, mid-summer soil temperatures are ideal for germination. The seeds sprout quickly, usually within 7-14 days.
As the plants grow, the days get shorter and cooler. This triggers the roots to store sugars, making them sweeter. A light frost actually improves the flavor of rutabagas, so don’t worry if a frost hits before you harvest. Just make sure you get them out of the ground before a hard freeze (below 25°F).
Another reason mid-summer works is that it avoids the peak of pest activity. Many root maggots and flea beetles are less active in late summer, so your rutabagas have a better chance of growing without damage.
Checking Your Local Frost Dates
To find your exact planting window, look up your county’s average first frost date. The University of Wisconsin Extension has a helpful map and chart. You can also use online tools like the Old Farmer’s Almanac frost date calculator.
Once you know your first frost date, count backward 100 days. That’s your latest planting date. For best results, plant a week or two earlier than that to give yourself a buffer.
Preparing Your Soil For Rutabagas
Rutabagas need loose, well-draining soil that’s rich in organic matter. They grow best in a pH between 6.0 and 6.5. If your soil is too acidic, the roots may develop clubroot or other diseases.
Here’s how to prepare your planting bed:
- Test your soil pH about 4-6 weeks before planting. You can buy a simple test kit at a garden center or send a sample to the UW Soil Lab.
- Amend the soil with compost or well-rotted manure. Work it in to a depth of 8-10 inches. This improves drainage and adds nutrients.
- Remove rocks and debris from the bed. Rutabagas need room to expand underground. Rocks can cause the roots to fork or become misshapen.
- Add a balanced fertilizer like 10-10-10 at a rate of 1 pound per 100 square feet. Avoid high-nitrogen fertilizers, which can cause leafy growth at the expense of root development.
- Rake the bed smooth and water it well a day before planting. This helps the soil settle and makes it easier to plant seeds.
If you’re planting in heavy clay soil, consider building a raised bed. Rutabagas struggle in compacted soil. Raised beds warm up faster in spring and drain better, which is a big help in Wisconsin’s wet summers.
Choosing The Right Rutabaga Variety
Not all rutabaga varieties are created equal. Some mature faster than others, which is important in Wisconsin’s short growing season. Here are a few reliable options:
- American Purple Top: The classic variety. Matures in 90-100 days. Tolerates light frost well.
- Laurentian: A Canadian heirloom that’s very cold-hardy. Matures in 95 days. Good for northern Wisconsin.
- Marian: A newer variety that’s resistant to clubroot. Matures in 100 days. Great for heavy soils.
- Nadadora: A hybrid that matures in 80-90 days. Perfect for late planting in southern Wisconsin.
For the best results, choose a variety that matches your planting window. If you’re planting on the late side, go with a faster-maturing type like Nadadora. If you have more time, American Purple Top is a reliable choice.
How To Plant Rutabaga Seeds
Planting rutabaga seeds is straightforward. Follow these steps for a successful crop:
- Create shallow furrows about 1/2 inch deep. Space the rows 18-24 inches apart. This gives the roots room to grow.
- Sow the seeds thinly along the furrow. Aim for 2-3 seeds per inch. You can always thin them later.
- Cover the seeds with fine soil and gently firm it down. Don’t pack it too hard, or the seeds may struggle to emerge.
- Water gently with a fine spray. Keep the soil consistently moist until the seeds germinate. This usually takes 7-14 days.
- Thin the seedlings when they are 2-3 inches tall. Leave 6-8 inches between plants. Crowded rutabagas produce small, misshapen roots.
If you’re planting in a row, you can also use a seed tape. This pre-spaced tape makes thinning unnecessary. Just lay it in the furrow and cover with soil.
Watering And Care
Rutabagas need about 1-1.5 inches of water per week. In Wisconsin, summer rains often provide enough moisture, but you may need to supplement during dry spells. Water deeply once or twice a week rather than lightly every day. Deep watering encourages roots to grow downward.
Mulching around the plants helps retain moisture and keeps the soil cool. Use straw, grass clippings, or shredded leaves. Apply a 2-3 inch layer after the seedlings are established. Mulch also suppresses weeds, which compete with rutabagas for nutrients.
Weed regularly, especially in the first few weeks. Rutabagas have shallow roots, so hand-pull weeds carefully. Avoid using a hoe too close to the plants, as it can damage the developing roots.
Fertilizing During The Growing Season
Rutabagas are moderate feeders. They benefit from a side-dressing of fertilizer about 4-6 weeks after planting. Use a low-nitrogen fertilizer like 5-10-10. Apply it at a rate of 1/2 pound per 100 square feet. Water it in well after application.
Avoid over-fertilizing, especially with nitrogen. Too much nitrogen leads to lush foliage but small, poor-quality roots. If your soil is already rich in organic matter, you may not need additional fertilizer at all.
Pest And Disease Management
Rutabagas in Wisconsin face a few common pests. Here’s what to watch for:
- Flea beetles: Small black beetles that chew tiny holes in leaves. Use row covers to protect young plants. Diatomaceous earth can also help.
- Root maggots: Small white larvae that tunnel into roots. Rotate crops and avoid planting in soil where other brassicas grew recently.
- Clubroot: A soil-borne disease that causes roots to swell and distort. Maintain a soil pH above 6.5 to reduce risk. Choose resistant varieties like Marian.
- Aphids: Small insects that suck sap from leaves. Spray with a strong stream of water or use insecticidal soap.
Prevention is the best strategy. Rotate your rutabaga crop every 3-4 years. Don’t plant them in the same spot where other brassicas (cabbage, broccoli, kale) grew the previous year. This reduces pest and disease buildup in the soil.
Harvesting Rutabagas In Wisconsin
Rutabagas are ready to harvest when the roots are 3-5 inches in diameter. This usually happens 90-110 days after planting. In Wisconsin, that means harvesting from late September through October.
Here’s how to tell if they’re ready:
- Check the size: Gently brush away soil from the top of the root. If it’s at least 3 inches across, it’s ready.
- Feel the firmness: A mature rutabaga feels solid and heavy. Soft or spongy roots are past their prime.
- Look at the leaves: When the leaves start to yellow and die back, the roots are usually ready.
To harvest, use a garden fork to loosen the soil around the root. Pull gently by the top, but be careful not to break the root. If the soil is heavy, you may need to dig around the root to free it.
After harvesting, cut off the tops (leaves) about 1 inch above the root. Leave the root end intact. Brush off excess soil, but don’t wash the rutabagas until you’re ready to use them. Washing removes the natural protective coating and shortens storage life.
Storing Your Rutabaga Harvest
Rutabagas store well for months if conditions are right. Here’s what to do:
- Cure the roots by leaving them in a cool, dark place for 1-2 weeks. This toughens the skin and improves storage.
- Store in a root cellar or a cool basement. Ideal temperature is 32-40°F with high humidity (90-95%).
- Use perforated plastic bags or wrap each rutabaga in newspaper. This prevents moisture loss while allowing air circulation.
- Check regularly for soft spots or mold. Remove any damaged roots immediately to prevent spread.
If you don’t have a root cellar, you can store rutabagas in a refrigerator for 2-3 months. Just put them in a plastic bag with a few holes for ventilation. They’ll keep well in the crisper drawer.
Common Mistakes To Avoid
Even experienced gardeners make mistakes with rutabagas. Here are the most common ones and how to avoid them:
- Planting too early: Leads to woody, bitter roots. Stick to mid-summer planting.
- Planting too late: Roots won’t mature before hard freeze. Check your frost dates.
- Overcrowding: Small, misshapen roots. Thin seedlings to 6-8 inches apart.
- Poor soil preparation: Rocky or compacted soil causes forked roots. Remove rocks and loosen soil deeply.
- Ignoring pests: Flea beetles and root maggots can ruin a crop. Use row covers and rotate crops.
- Harvesting too late: Roots become tough and pithy. Harvest when 3-5 inches in diameter.
By avoiding these pitfalls, you’ll have a much better chance of a successful rutabaga harvest.
Frequently Asked Questions
Can I plant rutabaga in spring in Wisconsin?
Spring planting is possible but not ideal. Rutabagas prefer cool weather, but spring-planted roots mature in summer heat, which makes them woody and bitter. Fall-harvested rutabagas are much sweeter. If you want a spring crop, plant as soon as the soil can be worked in April, and harvest before July.
How late can I plant rutabaga in Wisconsin?
The latest safe planting date depends on your region. In southern Wisconsin, you can plant as late as July 20. In northern areas, July 5 is the latest. Always check your first frost date and count backward 90-100 days. If you’re unsure, plant earlier rather than later.
Do rutabagas need full sun?
Yes, rutabagas grow best in full sun, meaning at least 6-8 hours of direct sunlight per day. They can tolerate partial shade, but the roots will be smaller and less flavorful. Choose a sunny spot in your garden for the best results.
What’s the difference between rutabaga and turnip?
Rutabagas are larger, sweeter, and have yellow flesh, while turnips are smaller, more peppery, and have white flesh. Rutabagas also take longer to mature (90-110 days vs. 40-60 days for turnips). In Wisconsin, rutabagas are a fall crop, while turnips can be planted in spring or fall.
Can I grow rutabaga in containers?
Yes, but choose a deep container (at least 12 inches) to allow root development. Use loose, well-draining potting mix. Keep the container in full sun and water regularly. Container-grown rutabagas may be smaller than garden-grown ones, but they’re still tasty.
Final Tips For Wisconsin Gardeners
Rutabagas are a rewarding crop for Wisconsin gardeners. They’re easy to grow, store well, and taste amazing after a light frost. The key is getting the timing right. Remember the golden rule: plant in mid-summer, about 10-12 weeks before your first frost.
If you’re new to growing rutabagas, start with a small patch. Try a few different varieties to see which ones perform best in your soil. Keep notes on planting dates and harvest times so you can refine your approach next year.
Don’t forget to share your harvest with friends and family. Roasted rutabaga, mashed rutabaga, or rutabaga fries are all delicious ways to enjoy your homegrown crop. With a little planning, you’ll have a steady supply of fresh rutabagas all winter long.
Happy planting, and enjoy the fruits (or roots) of your labor!