Tennessee’s temperate climate supports a March planting of kohlrabi, with a second crop possible in late summer. Finding the best time to plant kohlrabi in Tennessee depends on your specific region and the vegetable’s love for cool weather. This guide walks you through everything you need for a successful harvest.
Kohlrabi is a fast-growing, cool-season crop. It thrives when temperatures stay between 40°F and 75°F. In Tennessee, that means two distinct planting windows work best.
Best Time To Plant Kohlrabi In Tennessee
For most of Tennessee, the prime spring window opens in early to mid-March. Soil temperatures should be at least 40°F. A second planting happens in late summer, around August, for a fall harvest.
Here is a quick breakdown by region:
- West Tennessee (Memphis area): Plant spring crop from March 1 to March 15. Fall crop from August 1 to August 15.
- Middle Tennessee (Nashville area): Plant spring crop from March 10 to March 25. Fall crop from August 10 to August 25.
- East Tennessee (Knoxville area): Plant spring crop from March 20 to April 5. Fall crop from August 20 to September 5.
These dates are general guides. Always check your local frost dates. Kohlrabi can handle light frosts, but hard freezes below 25°F can damage young plants.
Why Timing Matters For Kohlrabi
Kohlrabi grows best in cool weather. If planted too late in spring, heat causes the bulbs to become woody and tough. If planted too early in fall, hot soil can stunt germination.
The plant needs about 55 to 70 days to mature. You want harvest to happen before summer heat arrives or after it fades in autumn.
Spring Planting Details
Start seeds indoors 4 to 6 weeks before your last frost date. For most of Tennessee, that means starting seeds in late January or early February.
- Use seed-starting mix in small pots or trays.
- Plant seeds ¼ inch deep.
- Keep soil moist and warm (around 70°F).
- Transplant seedlings outdoors after hardening off for a week.
Direct sowing is also possible. Wait until soil can be worked in early spring. Sow seeds ½ inch deep, spaced 1 inch apart. Thin to 6 inches apart once seedlings have two true leaves.
Hardening Off Seedlings
Before transplanting, gradually expose seedlings to outdoor conditions. Start with one hour of shade, then increase time and sunlight over a week. This prevents shock.
Fall Planting Details
For a fall harvest, plant kohlrabi in late summer. The goal is to have bulbs mature during cooler autumn weather. Count back 65 days from your first expected frost date.
In Tennessee, first frost dates range from late October in the east to mid-November in the west. So planting in mid-August to early September works well.
- Direct sow seeds ½ inch deep.
- Space rows 12 to 18 inches apart.
- Water consistently, especially during dry spells.
- Mulch around plants to keep soil cool.
Fall crops often taste sweeter. Cool nights increase sugar content in the bulbs.
Soil Preparation Tips
Kohlrabi prefers well-draining soil rich in organic matter. A pH between 6.0 and 7.5 is ideal. Test your soil before planting.
Add compost or aged manure a few weeks before planting. Work it into the top 6 inches of soil. Avoid fresh manure, which can burn roots.
If your soil is heavy clay, consider raised beds. Kohlrabi bulbs can deform in compacted soil.
Watering And Fertilizing
Keep soil consistently moist. Kohlrabi needs about 1 to 1.5 inches of water per week. Inconsistent watering can cause bulbs to crack or become tough.
Use a balanced fertilizer (10-10-10) at planting time. Side-dress with nitrogen when bulbs start to swell. Too much nitrogen can cause leafy growth at the expense of bulbs.
Common Pests And Problems
Kohlrabi faces a few pests in Tennessee gardens. Watch for these:
- Flea beetles: Small holes in leaves. Use row covers or neem oil.
- Cabbage worms: Green caterpillars on leaves. Handpick or use Bt spray.
- Aphids: Clusters on stems. Blast off with water or use insecticidal soap.
- Clubroot: Swollen roots and stunted growth. Rotate crops and maintain soil pH above 7.0.
Rotate kohlrabi with non-brassica crops each year. This reduces disease buildup in soil.
Harvesting Kohlrabi
Harvest when bulbs are 2 to 3 inches in diameter. Larger bulbs become woody and lose flavor. Cut the stem at soil level with a sharp knife.
Leaves are also edible. Use them in salads or cook like spinach. Harvest leaves when young for best taste.
Store kohlrabi in the refrigerator for up to two weeks. Remove leaves to prevent moisture loss. Bulbs can also be stored in a root cellar for several months.
Varieties That Work Well In Tennessee
Choose varieties suited to your climate. Here are some reliable options:
- Early White Vienna: Fast-maturing, 55 days. Tender bulbs.
- Kolibri: Purple-skinned, 55 days. Sweet flavor.
- Grand Duke: Hybrid, 55 days. Heat tolerant.
- Kossak: Large bulbs, 60 days. Good for fall planting.
Purple varieties often handle heat slightly better than green ones. But all kohlrabi prefers cool conditions.
Extending The Season
Use row covers or cold frames to protect plants from early frosts. This can extend your harvest by a few weeks in spring or fall.
In mild Tennessee winters, you can even plant a winter crop in a cold frame. Choose a hardy variety and provide protection from hard freezes.
Common Mistakes To Avoid
- Planting too late in spring. Heat stress ruins bulb quality.
- Planting too early in fall. Hot soil prevents germination.
- Overcrowding. Thin seedlings to 6 inches apart.
- Inconsistent watering. Causes cracking and tough texture.
- Ignoring pests. Check plants weekly for signs of damage.
Frequently Asked Questions
Can I Plant Kohlrabi In Tennessee In Summer?
Summer planting is not recommended. Heat causes bulbs to become woody and bitter. Stick to spring and fall windows.
What Is The Best Month To Plant Kohlrabi In Tennessee?
March is best for spring planting. August is best for fall planting. Adjust by two weeks depending on your region.
How Long Does Kohlrabi Take To Grow In Tennessee?
Most varieties mature in 55 to 70 days. Cool weather can slow growth slightly, but heat speeds it up.
Can I Grow Kohlrabi In Containers In Tennessee?
Yes. Use a container at least 12 inches deep. Ensure good drainage and consistent watering. Place in full sun.
Does Kohlrabi Need Full Sun In Tennessee?
Yes, full sun is best. At least 6 hours of direct sunlight daily. Partial shade can result in smaller bulbs.
What Should I Do If My Kohlrabi Bulbs Are Small?
Check soil fertility and watering. Add balanced fertilizer and ensure consistent moisture. Thin plants if overcrowded.
Can I Plant Kohlrabi After Tomatoes In Tennessee?
Yes, kohlrabi makes a good fall crop after summer tomatoes. Just ensure soil is refreshed with compost.
Is Kohlrabi Frost Tolerant In Tennessee?
Yes, it can handle light frosts. Hard freezes below 25°F may damage plants. Use row covers for protection.
By following these guidelines, you can enjoy fresh, tender kohlrabi from your Tennessee garden. Spring and fall plantings give you two harvests each year. With proper care, this versatile vegetable rewards you with crisp, mild bulbs perfect for salads, roasting, or eating raw.
Remember to adjust planting dates based on your local weather patterns. Soil temperature and frost dates are your best guides. Keep a garden journal to track what works in your specific location.
Kohlrabi is a forgiving crop for beginners. It grows quickly and requires minimal maintenance. Once you master the timing, you will have a steady supply of this underrated vegetable.
Start planning your spring planting now. Check your soil, order seeds, and mark your calendar. Your Tennessee garden will thank you.