Best and Worst Potato Companion Plants

When planning your garden, potatoes offer a unique challenge because there are many plants that grow well in close proximity to potatoes, but there are also certain plants you should avoid planting near them. An understanding of companion planting strategies will help you learn how best to plan your potato plot.

Good companion planting strategies are especially important in small gardens or wherever careful space planning is needed. Learn which plants make the best and worst potato companions.

What Is Companion Planting?

Companion planting is defined as the practice of planting different species of plants close together based on their ability to enhance one another in some way. Common reasons why plants might be regarded as good companions include:

• Non-competing growth habits: Plants can have different but complementary growth habits that do not compete with one another. Pairing tall upright plants with ground-hugging vines, for example, offers efficient use of garden space. Or pairing deep-rooted vegetables with shallow-rooted vegetables offers similar efficiency. 
• Similar growth needs: Plants might have similar needs for fertilizing, water, or sunlight, which makes it easier to take care of them. Pairing together plants with high water needs, for example, makes watering more efficient and ensures all plants receive the right amount of water. 
• Pest deterrent: Some plants are known to repel certain insect pests that feast on a particular plant. Marigolds, for example, are good companions for many plants for this reason. Other plants attract beneficial insects that serve as predators for harmful insects.
• Soil balance: Plants with different root structures when planted together may aerate the soil allowing them to pull a variety of nutrients from different parts of the soil. Those with deep roots such as melons and tomatoes pull from deeper in the soil while those with taproots or tubers like carrots help to break up compaction.
• Nutrient replenishment: Some plants may improve the nutritional value of the soil. Legumes such as peas and beans, for example, are good companions for many plants because they fix nitrogen into a form that makes it available for many other plants. Broccoli and cabbage, on the other hand, use up the nitrogen and may deplete the soil.
• Flavor enhancer: Some plants are said to enhance the flavor of other edible plants when they are grown close together. For example, planting certain herbs such as basil with certain fruits and vegetables such as tomatoes is believed to improve growth and flavor.

Best Potato Companion Plants

Potatoes grow deep in the soil, which suggests that the best companions will be those with above-ground growth habits that do not interfere with the potato tubers. Still, some root vegetables are beneficial because they help repel pests. Here's a list of the best potato companion plants:

Vegetables

• Beans
• Cabbage and other members of the brassica family (broccoli, Brussels sprouts, cabbage, cauliflower)
• Corn
• Horseradish
• Lettuce
• Peas
• Radish
• Scallion
• Spinach

Culinary Herbs

• Basil
• Cilantro
• Chamomile
• Lovage
• Marjoram
• Parsley
• Thyme
  

Ornamentals/flowers

• Catnip 
• Marigold
• Nasturtium
  
• Petunia
• Sweet Alyssum
• Tansy
• Yarrow
  

Lettuce, spinach, scallions, and radishes are shallow-rooted veggies that are good choices for occupying the spaces between potato plants. Because potatoes are harvested late in the season, the best choices for planting around the potato hills will be early-season vegetables that will be harvested well before you need to stomp around the garden to dig up the potatoes.

Several plants are said to enhance the flavor of the potato tubers, including dead nettle, horseradish, and marigolds, although none of this has been scientifically proven.

Beans and other legumes are good companion plants for nitrogen-loving vegetables because they increase nitrogen levels in the soil. 

Horseradish is said to make potatoes resistant to pests and disease, and petunias and alyssum will also attract beneficial insects that feast on insects that attack potatoes. Colorado potato beetles are a particular problem for potatoes, and among the plants that repel this damaging pest are tansy, coriander, and catnip.

Worst Potato Companion Plants

Proper companion planting techniques can also mean not locating some plant species close together if they have a negative influence on one another. For example some plants: 

• Negatively influence the taste of other plants
• Lure the same destructive insects
• Compete for sunlight, soil nutrients, or space
  
• Are susceptible to the same disease

Potatoes are members of the nightshade family, so avoid planting potatoes near any other nightshade family members such as peppers, tomatoes, tomatillos, eggplant, and okra. And, avoid planting potatoes is the same location where nightshade plants have recently been grown.

Because they share many of the same genes, all members of a crop family are susceptible to the same diseases and pests. Locating nightshade family members near one another creates optimal conditions for certain fungal and bacterial diseases to thrive. Follow crop rotation best practices and allow a full two years before replanting members of the same crop family in the same location.

• Carrot
• Cucumber
• Eggplant
• Fennel
• Okra
• Onion
• Pepper
• Pumpkin
• Raspberry
• Squash
• Sunflower
• Tomato
• Tomatillo
• Turnip