How to Grow Kohlrabi in Pennsylvania

Kohlrabi, a member of the brassica family, is a versatile and nutritious vegetable that is gaining popularity among home gardeners. Its unique flavor and crunchy texture make it an excellent addition to salads, stir-fries, and slaws. For gardeners in Pennsylvania, understanding how to grow kohlrabi can enhance your garden’s diversity and provide a bountiful harvest. This article will guide you through the essential steps to successfully cultivate kohlrabi in Pennsylvania’s varying climate conditions.

Understanding Kohlrabi

Kohlrabi, also known as turnip cabbage, can be eaten raw or cooked. The bulbous stem grows above ground and can be harvested when it measures about 3-5 inches in diameter. It is available in green and purple varieties, each possessing a slightly different taste profile. The leaves are also edible and can be used similarly to collard greens or kale.

Best Time to Plant Kohlrabi in Pennsylvania

In Pennsylvania, kohlrabi is typically grown as an annual crop with two main planting seasons: spring and fall. The timing for planting varies depending on the specific region within the state.

Spring Planting

1. Soil Temperature: Kohlrabi prefers cool temperatures, thriving best at 60-70°F. In Pennsylvania, it’s best to plant seeds outdoors when the soil temperature reaches around 45°F.
2. Planting Time: Generally, you can start planting kohlrabi seeds outdoors from mid-March to early May. For an earlier harvest, consider starting seeds indoors 4-6 weeks prior to your last expected frost date.

Fall Planting

1. Timing: For a fall crop, sow seeds from mid-July to early August. This allows the plants enough time to mature before the first frost.
2. Transplanting: If starting indoors, transplant seedlings around 4 weeks before the average first frost date (approximately mid-October in many parts of Pennsylvania).

Choosing the Right Location

Kohlrabi requires full sun for optimal growth, so select a location that receives at least 6-8 hours of direct sunlight daily. Additionally, choose well-drained soil rich in organic matter for the best results. Avoid areas prone to standing water or heavy clay soils.

Soil Preparation

Before planting, prepare your garden bed by:

1. Testing Soil pH: Kohlrabi prefers a slightly acidic to neutral pH range of 6.0-7.0. Conduct a soil test and amend accordingly with lime or sulfur if needed.
2. Adding Organic Matter: Incorporate compost or well-rotted manure into your garden beds to improve soil fertility and structure.
3. Tilling: Loosen the soil up to 12 inches deep to ensure proper root development.

Planting Kohlrabi Seeds

Direct Sowing

1. Seed Depth: Sow seeds about ½ inch deep in rows spaced 12-18 inches apart.
2. Spacing: Once seedlings emerge and are about 2-3 inches tall, thin them out to 6-8 inches apart to allow ample space for bulb development.

Transplanting Seedlings

If you started seeds indoors, transplant seedlings carefully:

1. Timing: Transplant when seedlings have at least two true leaves.
2. Watering: Water thoroughly before removing seedlings from their containers to minimize transplant shock.

Watering and Fertilizing

Kohlrabi requires consistent moisture for optimal growth but does not tolerate waterlogged conditions. Here’s how to manage watering and fertilization effectively:

Watering

1. Frequency: Water kohlrabi plants deeply once a week, increasing frequency during dry spells.
2. Soil Moisture: Ensure that the top inch of soil is consistently moist but not soggy.

Fertilizing

To promote healthy growth:

1. Initial Fertilizer Application: About two weeks after planting, apply a balanced fertilizer (10-10-10) according to package instructions.
2. Additional Feeding: A second application may be necessary midway through the growing season if growth appears slow or leaves show signs of nutrient deficiency.

Pest and Disease Management

Kohlrabi is susceptible to various pests and diseases common in Pennsylvania gardens:

Common Pests

1. Cabbage Worms: These green caterpillars feed on leaves; handpick them off or use organic insecticidal soap.
2. Aphids: Small green bugs that cluster on stems; control with insecticidal soap or neem oil.
3. Flea Beetles: Tiny black beetles that create small holes in leaves; row covers can deter them during early growth.

Diseases

1. Downy Mildew: Fungal disease that can occur during humid weather; ensure proper spacing for airflow.
2. Black Rot: A bacterial disease causing yellow V-shaped lesions on leaves; practice crop rotation and avoid overhead watering.

Harvesting Kohlrabi

Timing is crucial when it comes to harvesting kohlrabi:

1. When to Harvest: Kohlrabi is ready for harvest when bulbs are about 3-5 inches in diameter, typically between 50-70 days after planting.
2. Harvest Method: Use a sharp knife or garden shears to cut the bulb from the stem just above the soil line.

Storing Kohlrabi

Freshly harvested kohlrabi can last several weeks under optimal storage conditions:

1. Storage Conditions: Store unwashed kohlrabi in a cool, dark place with high humidity (ideally around 32°F).
2. Refrigeration: Alternatively, place it in the crisper drawer of your refrigerator wrapped loosely in a plastic bag.

Culinary Uses of Kohlrabi

Once harvested, kohlrabi can be enjoyed in various ways:

1. Raw: Peel and slice into sticks for fresh snacks or salads.
2. Cooked: Roast or steam kohlrabi as a delicious side dish or add it to soups and casseroles.
3. Greens: Cook the leaves like any other leafy green for added nutrition.

Conclusion

Growing kohlrabi in Pennsylvania is a rewarding endeavor that adds both flavor and nutrition to your home garden plate. By following proper planting times, providing adequate care troubleshooting pest issues, and knowing when to harvest, you can enjoy this unique vegetable throughout its growing season and beyond! Whether you’re a seasoned gardener or just starting out, kohlrabi offers an exciting challenge that will enhance your gardening experience while broadening your culinary horizon!