Complete Gardening
Gardening enthusiasts often focus on what plants grow well together, but knowing which plant combinations to avoid is equally important. Some plants simply don’t make good neighbors, engaging in a subtle form of sabotage that can harm your garden’s health and productivity.
These plant pairs may compete for nutrients, attract pests, or inhibit each other’s growth through chemical means.
By learning about these antagonistic relationships, you can make informed decisions about your garden’s layout, ensuring that your plants thrive rather than merely survive. Here are 14 plant combos you should keep apart.
1. Carrots and Dill
Carrots and dill might both feature in a summer salad, but growing them together is a recipe for disaster. Dill can hinder carrot growth by releasing chemicals that inhibit seed germination and stunt development.
Additionally, dill can attract beneficial insects like parasitic wasps, but these can also disturb carrot growth. Keeping these plants apart ensures that neither suppresses the other.
Plant dill with other companions like cucumbers, and save the carrot bed for onions or lettuce, which are more compatible. This separation helps maintain healthy, vigorous growth for all involved.
2. Cabbage and Grapes
Cabbage and grapes may both thrive in temperate climates, but they don’t belong together in your garden. Grapes can overshadow cabbage, competing for sunlight and air circulation.
Moreover, both are susceptible to fungal diseases like powdery mildew, which can spread rapidly between these two. Separating these plants can reduce the risk of disease transmission and ensure both receive adequate light and air.
Consider growing cabbage with companions like herbs that deter pests, and trellis grapes away from leafy vegetables. This strategy promotes healthier, more productive growth for both plant species.
3. Tomato and Corn
Tomatoes and corn might seem like they belong together in a summer garden, but they actually compete fiercely for nutrients. Both plants are heavy feeders, extracting large amounts of nitrogen from the soil.
Planting them side by side can lead to nutrient depletion, stunting growth. Additionally, both crops attract similar pests, like the corn earworm, that can wreak havoc if their population explodes.
By separating these two, you can give each the space and resources they need. Consider rotating them with legumes or other nitrogen-fixing plants to improve soil fertility.
4. Fennel and Most Vegetables
Fennel is a notoriously poor companion for many vegetables, thanks to allelopathic chemicals it releases into the soil. These chemicals can inhibit growth in plants like beans, tomatoes, and cabbage, causing them to struggle.
While fennel attracts beneficial insects, its toxicity to many common garden crops makes it tricky to place. Grow fennel in its own dedicated area or alongside other strong, aromatic herbs that can tolerate its presence.
Keeping it separate from most vegetables ensures your garden thrives without the risk of suppressed growth or inhibited productivity.
5. Radishes and Hyssop
Radishes and hyssop might seem harmless, but they can clash in the garden. Hyssop can inhibit radish growth through chemical interactions, leading to poor root development and stunted plants.
Additionally, hyssop can attract beneficial pollinators, but these may not benefit radishes. Keeping these plants apart ensures radishes can mature without interference.
Plant radishes with lettuce or peas, which can benefit from their quick growth and provide shade. Hyssop, on the other hand, can enhance the growth of grapes or cabbages, making it a valuable companion in other parts of your garden.
6. Onions and Beans
Onions and beans might share space in a casserole, but they’re not friends in the garden. Onions release sulfur compounds that can negatively affect the growth of beans, inhibiting root development and shoot growth.
Beans, on the other hand, can overshadow young onion plants, competing aggressively for sunlight. Separating these plants is crucial for optimal growth.
Pair onions with carrots or beets, which can benefit from the pest-repellent properties of onions. Meanwhile, beans thrive alongside nitrogen-hungry plants like corn or squash, improving their growth and yield.
7. Cucumbers and Aromatic Herbs
Cucumbers and aromatic herbs like sage and basil might sound like a flavorful combination, but they’re better apart. Aromatic herbs can overshadow young cucumber plants, competing for light and space.
Additionally, these herbs can alter the microclimate around cucumbers, affecting moisture levels and growth rates. By separating them, each can thrive in its preferred environment.
Cucumbers pair well with corn or sunflowers, which provide natural trellises and shade. Aromatic herbs benefit from proximity to flowers like marigolds, which can enhance their growth and deter pests.
8. Lettuce and Broccoli
Lettuce and broccoli might both enjoy cool weather, but they’re not ideal neighbors. Broccoli can overshadow lettuce, blocking sunlight and impeding its growth.
Additionally, as broccoli matures, its sprawling leaves can crowd lettuce plants, leading to stunted growth. Separating these crops can ensure both receive the light and space they need.
Plant lettuce with carrots or radishes, which can benefit from its fast growth and shading. Broccoli, meanwhile, pairs well with other members of the brassica family, creating a harmonious planting that maximizes both space and yield.
9. Peas and Onions
Peas and onions are an unfortunate match in the garden. Onions release compounds that can inhibit pea root growth, stunting the plants and reducing yields. Similarly, the rapid growth of peas can overshadow onions, limiting their light exposure.
Keep these plants apart to ensure each thrives. Plant peas with companions like carrots or cucumbers, which can benefit from their nitrogen-fixing abilities.
Onions do well with cabbage or lettuce, which can take advantage of their pest-repelling properties while ensuring both plants grow healthily without competition.
10. Strawberries and Cabbage
Strawberries and cabbage can be a problematic pair in the garden. Cabbage’s sprawling leaves can overshadow strawberries, reducing sunlight and air circulation. Additionally, both attract pests like slugs, which can damage the plants if not controlled.
By separating these crops, you can manage pests more effectively and ensure each plant receives adequate light and air. Strawberries pair well with garlic or onions, which can deter pests.
Meanwhile, cabbage thrives with companions like dill or rosemary, which can enhance its growth and protect against common garden nuisances.
11. Sunflowers and Potatoes
Sunflowers and potatoes are both sun-loving plants, but they don’t thrive as neighbors. Sunflowers can deplete soil moisture and nutrients, leaving potatoes struggling to grow. Additionally, they can overshadow potatoes, blocking sunlight and impeding photosynthesis.
Avoid planting them together to ensure each plant receives the resources it needs. Grow sunflowers with beans or vining plants, which can climb their sturdy stalks.
Potatoes do well with beans or peas, benefiting from their nitrogen-fixing abilities and ensuring a productive, healthy garden space for all plants involved.
12. Garlic and Beans
Garlic and beans don’t make the best companions in the garden. Garlic releases sulfur compounds that can inhibit bean growth, affecting both roots and shoots.
Conversely, beans can overshadow young garlic plants with their rapid growth, competing for sunlight and nutrients. Separate these plants to optimize growth and yield. Garlic pairs well with strawberries or tomatoes, offering pest protection.
Beans, meanwhile, thrive with corn or squash, which can benefit from their nitrogen-fixing properties, ensuring a healthy, balanced garden environment for all involved.
13. Potatoes and Tomatoes
Potatoes and tomatoes may share the same botanical family, but they’re more rivals than relatives in the garden. Both plants are susceptible to blight, a destructive disease that spreads quickly when these plants are in close proximity.
Moreover, they compete heavily for nutrients, which can lead to diminished growth and fewer yields. It’s best to keep these two separated to prevent disease spread and nutrient competition.
Rotate them with other crops to break disease cycles and improve soil health, ensuring a bountiful harvest for each plant.
14. Mint and Almost Everything
Mint is notorious for its invasive nature, making it a challenging companion for most plants. Its rapid growth can quickly overshadow and crowd out nearby plants, stealing nutrients and space.
Additionally, mint’s strong aroma can alter the microclimate, affecting neighboring plants’ growth. To prevent mint from taking over, plant it in containers or isolated garden beds.
This containment allows mint to thrive without impacting other plants negatively. Mint can benefit from companion plants like tomatoes and cabbage, which tolerate its presence, ensuring a harmonious and productive garden.