When To Plant Turnips In Illinois

If you’re wondering when to plant turnips in Illinois, you’re in the right place. Getting the timing right is the single most important step for a great harvest of sweet roots and tasty greens.

Illinois has a wide range of climates, from the longer season in the south to the cooler, shorter summers up north. This means your planting dates will shift a bit depending on where you live. But don’t worry, the basic rules are simple to follow. This guide will walk you through the best times for spring and fall planting, how to prepare your soil, and tips for keeping your turnips growing strong.

Turnips are a cool-season crop. They thrive in the milder temperatures of spring and fall. Heat is their enemy, as it makes them taste bitter and grow poorly. For the best results, you’ll plan two main planting periods.

Spring Planting Window

For a spring harvest, you need to get your seeds in the ground early. The goal is to have them mature before the summer heat arrives.

Southern Illinois (Zones 6a-7a): Plant from late March to mid-April.
Central Illinois (Zones 5b-6a): Plant from early April to late April.
Northern Illinois (Zones 5a-5b): Plant from mid-April to early May.

A good rule of thumb is to sow seeds as soon as the soil can be worked. That means it’s no longer frozen and is dry enough not to clump together. If you have a late frost after planting, don’t panic. Turnip seedlings can handle a light frost.

Fall Planting Window (The Best Time)

Fall is often the best time for planting turnips in Illinois. The cooling temperatures make turnips sweet and crisp. You’ll count backwards from your first expected fall frost.

For a roots-only harvest, plant seeds about 6-8 weeks before the first frost.
If you want both roots and greens, plant 8-10 weeks before the first frost.

Here’s a general fall planting schedule:

Northern Illinois: Plant from early August to early September.
Central Illinois: Plant from mid-August to mid-September.
Southern Illinois: Plant from late August to late September.

Fall-planted turnips often have less pest pressure and a more reliable harvest. The can even withstand a couple hard frosts, which makes them even sweeter.

Choosing the Right Turnip Variety

Picking a variety suited to your goals and season is key. Some are bred for fast greens, others for large roots.

For Greens & Roots: ‘Purple Top White Globe’ is a classic, reliable choice.
For Tender Greens: ‘Seven Top’ or ‘Shogoin’ are excellent.
For Sweet, Quick Roots: ‘Hakurei’ or ‘Tokyo Cross’ are fast-maturing and delicious.

Preparing Your Soil for Success

Turnips need loose, well-drained soil to form nice round roots. If the soil is to hard or rocky, the roots will become misshapen.

Loosen the Soil: Till or dig the area to a depth of at least 12 inches.
Amend with Compost: Mix in 2-3 inches of finished compost. This improves drainage and fertility.
Check the pH: Turnips prefer a soil pH between 6.0 and 7.0. A simple home test kit can tell you if you need to adjust it.
Fertilize Lightly: Use a balanced fertilizer (like a 10-10-10) at planting time. Avoid high-nitrogen formulas, which encourage leafy growth at the expense of the root.

How to Plant Turnip Seeds

Planting turnips is straightforward. They grow best from seed sown directly in the garden.

Rake the soil smooth, removing any large clumps or stones.
Sow seeds about ½ inch deep. You can plant them in rows or broadcast them for a patch.
Space seeds about 1 inch apart in rows that are 12-18 inches apart.
Cover the seeds lightly with soil and pat it down gently.
Water the area thoroughly with a gentle spray to avoid washing the seeds away.

Seeds will typically sprout in 4 to 7 days if the soil is moist.

Caring for Your Growing Turnips

Once they’re up, a little consistent care will ensure a healthy crop.

Thinning is Crucial: When seedlings are 3-4 inches tall, thin them to stand 4-6 inches apart. Use the thinned greens in a salad! Crowded turnips won’t form good roots.
Watering: Keep the soil consistently moist, providing about 1 inch of water per week. Inconsistent watering leads to woody or cracked roots.
Weeding: Keep the area weed-free, especially when plants are young. Weeds compete for water and nutrients.
Pest Watch: Watch for flea beetles (tiny holes in leaves) and cabbage worms. Row covers installed right after planting are the best prevention. For mild infestations, you can pick pests off by hand.

Harvesting at the Perfect Time

Knowing when to harvest ensures the best flavor and texture.

For Greens: You can start harvesting young leaves when they are 4-6 inches tall. Always leave some leaves so the root can continue to grow.
For Roots: Harvest when roots are 2-3 inches in diameter for the best tenderness. You can leave them in the ground longer, but they may become tough in warm weather.
Fall Crop Bonus: You can mulch fall turnips heavily with straw and harvest them right into early winter. A light frost improves there flavor.

To harvest, simply grasp the base of the greens and pull gently. If the soil is hard, loosen it first with a garden fork.

Common Problems and Simple Solutions

Even with good care, you might encounter a few issues.

Woody or Bitter Roots: Caused by hot weather or letting them grow to large. Stick to the planting windows and harvest on time.
Cracked Roots: This is from uneven watering. Try to keep soil moisture steady.
Poor Root Formation: Usually caused by crowded plants, poor soil, or to much nitrogen fertilizer. Thin properly and amend your soil with compost.
Bug Damage: Row covers are your best defense. If pests appear, insecticidal soap can help control them.

FAQ: Your Illinois Turnip Questions Answered

Can you plant turnips in the summer in Illinois?

It’s not recommended. Summer heat stresses turnips, making them bolt (flower) and causing roots to be bitter and pithy. For a continuous harvest, stick to early spring and late summer/fall plantings.

How long do turnips take to grow?

Most varieties are ready for harvest 45 to 60 days after planting. Some fast “baby” varieties can be ready in 30 days for small, tender roots. Always check the seed packet for “Days to Maturity.”

Can I grow turnips in containers?

Absolutely. Choose a container at least 12 inches deep and wide. Use a quality potting mix, keep it watered, and thin the seedlings. This is a great option if your garden soil is heavy clay.

What are good companion plants for turnips?

Turnips grow well near peas, beans, and onions. Avoid planting them near other members of the cabbage family (like broccoli or kale) to help reduce pest problems.

Are turnip greens edible?

Yes! The greens are highly nutritious and delicious when sautéed or added to soups. Harvest them regularly to encourage new growth, but remember to leave enough for the root to develop.

By following these simple guidelines for when to plant turnips in Illinois, you’ll set yourself up for a succesful harvest. Whether you’re after the crisp roots or the vitamin-packed greens, a little timing goes a long way. Remember, the fall planting is often the most rewarding, yielding the sweetest crops as the weather cools. With proper soil preparation and care, you’ll be enjoying homegrown turnips from your own garden.