Kohlrabi is a cool-weather vegetable known for its unique bulbous structure and mild, crunchy flavor. While kohlrabi is easy to grow and versatile in the kitchen, it’s important to be mindful of what other plants you grow alongside it.

Companion planting is the practice of choosing which plants to grow together in a garden to promote growth, reduce pests, and improve overall garden health.

However, not all plants are beneficial when planted near kohlrabi. Some vegetables and herbs can stunt its growth, attract harmful pests, or even compete for nutrients. Knowing what not to plant with kohlrabi is just as important as knowing which plants are good companions.

In this article, we’ll explore 10 plants you should avoid planting next to kohlrabi. Understanding these incompatible plant relationships will help you optimize your garden space, improve yields, and maintain healthier plants overall.

Related: Best Fertilizer For Kohlrabi

What Not To Plant With Kohlrabi? 10 Plants You Should Avoid

1. Beans

Beans are a popular companion plant for many vegetables, but they are not ideal neighbors for kohlrabi. Beans, especially pole beans, can compete with kohlrabi for space and nutrients, and their extensive root systems can interfere with kohlrabi’s shallow roots. Additionally, beans and kohlrabi are susceptible to similar pests like aphids, and growing them together can increase the likelihood of pest infestations.

2. Cabbage Family (Brassicas)

Since kohlrabi belongs to the Brassica family (which also includes cabbage, broccoli, and cauliflower), planting it next to other brassicas can lead to nutrient competition. These plants require similar nutrients, and growing them too close together can deplete the soil of essential elements. Additionally, these plants are prone to similar diseases, such as cabbage worms, which can spread easily among them.

3. Tomato

Tomatoes are commonly grown in vegetable gardens, but they do not pair well with kohlrabi. Both plants are heavy feeders, meaning they require a lot of nutrients from the soil. Growing them together can lead to nutrient depletion, affecting both plants’ health. Additionally, tomatoes can create a lot of shade, which may inhibit kohlrabi’s growth.

4. Potatoes

Kohlrabi and potatoes should not be planted near each other. Potatoes are known for their extensive root systems that can compete for space and nutrients. Both plants also attract pests like aphids and beetles, which can damage the foliage and interfere with the growth of the other plant. Additionally, potatoes and kohlrabi both prefer slightly different soil conditions, making them poor companions.

5. Strawberries

Strawberries and kohlrabi should be kept at a distance. While strawberries are low-growing plants, they are still competitors for space and nutrients. Additionally, strawberries may attract pests like slugs and snails, which can also harm kohlrabi plants. Since strawberries prefer acidic soil and kohlrabi thrives in slightly alkaline conditions, this pairing can lead to poor results for both plants.

6. Garlic and Onions

Garlic and onions can interfere with kohlrabi’s growth because they release compounds that can stunt the growth of neighboring plants. Both garlic and onions can also attract pests like thrips and aphids, which can be problematic for kohlrabi, as it is susceptible to the same pests. Moreover, these plants have strong root systems that can compete for space and nutrients in the soil, affecting the kohlrabi’s overall development.

7. Carrots

Carrots are another vegetable that does not pair well with kohlrabi. Carrots and kohlrabi have similar root structures, meaning they can end up competing for nutrients and space in the soil. Additionally, carrots can attract pests like carrot flies, which can also affect kohlrabi. While carrots don’t directly harm kohlrabi, the competition for resources makes them a poor companion plant.

8. Peas

Peas, like beans, are legumes that can fix nitrogen in the soil, which can be beneficial for other plants. However, they are not ideal companions for kohlrabi. Peas have a shallow root system, which can crowd the kohlrabi’s deeper roots, causing them to compete for space and nutrients. Moreover, peas attract aphids, which can harm kohlrabi and other vegetables nearby.

9. Spinach

Spinach is another plant that does not make a good companion for kohlrabi. Both plants prefer cool weather, but they also have different growth habits. Spinach grows quickly and can outcompete kohlrabi for space, light, and nutrients. Additionally, spinach is prone to diseases like downy mildew, which can spread to kohlrabi if planted too close.

10. Corn

Corn and kohlrabi are not compatible due to their different growth habits and nutrient needs. Corn grows tall and can shade the kohlrabi, preventing it from receiving adequate sunlight. Additionally, corn requires a lot of nitrogen, which could deplete the soil and leave little nutrients for kohlrabi. This nutrient competition makes corn an unsuitable companion for kohlrabi in the garden.

What Not To Plant With Kohlrabi FAQs 

1. Why is companion planting important with kohlrabi?

Companion planting helps improve plant growth, prevent pest infestations, and make the most of available nutrients in the soil. It is essential for maintaining healthy kohlrabi and ensuring better harvests.

2. Can I plant kohlrabi with other members of the cabbage family?

It is best to avoid planting kohlrabi with other cabbage family members, as they compete for nutrients and can attract the same pests, leading to poor growth and increased risk of disease.

3. What should I plant with kohlrabi instead?

Ideal companions for kohlrabi include herbs like basil, oregano, and dill, as well as other vegetables like lettuce, radishes, and peas.

4. Can I plant kohlrabi and beans together?

Kohlrabi and beans are not good companions because beans can compete with kohlrabi for nutrients and space, negatively affecting both plants’ growth.

5. Does kohlrabi attract pests?

Yes, kohlrabi can attract pests like aphids, cabbage worms, and flea beetles, especially when planted near other brassicas or plants that attract similar pests.

6. How far apart should I plant kohlrabi from other crops?

Kohlrabi should be spaced at least 12 inches apart from other plants to ensure it has enough room for root development and to avoid competition for nutrients.

7. Can I grow kohlrabi in containers?

Yes, kohlrabi can be grown in containers, but it is important to choose a large enough container to accommodate its root system and ensure it has adequate sunlight.

Conclusion

In conclusion, knowing what not to plant with kohlrabi is an essential part of creating a thriving vegetable garden.

By avoiding plants that compete for nutrients, attract the same pests, or require similar soil conditions, you can help kohlrabi grow to its full potential.

Keep in mind that proper spacing, choosing the right companions, and maintaining a balanced garden environment will not only benefit your kohlrabi but also improve the health of your entire garden.