Understanding companion plant strategies helps plan the best gardens without using chemical pesticides to control insects. Potatoes are large plants that benefit significantly from certain companion plants in the gardens. Others only attract and compound issues. Companion plants enhance one another in some way. Reasons companions help your potato plants. 

 #1 Bug Prevention: Many plants are famous for repelling insects from potatoes. Marigolds are ideal for this reason. Other plants attract beneficial insects that serve as predators of harmful insects. 

 #2 Growth requirements: Companion plants have similar plant food, light, and water needs, which makes them easier to care for. Pairing plants with high water needs, for example, makes watering more efficient and ensures all plants receive the right amount of irritation. 

 #3 No Competition: Plants often have complementary habits that do not compete. Pairing tall upright plants with low-vining plants efficiently use garden space. Pairing deep-rooted vegetables with shallow-rooted vegetables offers similar efficiency. 

 #4 Nutrient replacement: Some plants improve your garden’s nutritional value. Legumes are companions because they make nitrogen in the soil available for many other plants. 

 #5 The Perfect Soil: Plants either consume or replenish minerals in the soil, prevent soil depletion, and reduce plant food needs. Examples include beans and peas adding nitrogen to the soil; broccoli and cabbage use nitrogen. 

 #6 Flavor enhancer: Some plants enhance other edible plants’ flavor when grown close together. 

 Planting strategies are essential in small gardens when careful planning is required.  Visit my companion planting guide – Harvesting 100 Pounds of Potatoes 

 Potatoes grow deep, suggesting the best companions are those with above-ground habits that do not interfere with the potato tubers. Lettuce, radishes, scallions, and spinach have shallow roots perfect for occupying the spaces between potato plants. Potatoes are harvested late in the season. The ideal companion plants around the potato hills are early-season vegetables harvested well before you dig up the potatoes. 

 Several plants are said to enhance the flavor of the potatoes, including dead nettle, horseradish, and marigolds. Beans and other legumes are companion plants because they increase nitrogen levels in the soil.  

Horseradish makes potato plants resistant to disease. Petunias and alyssum attract beneficial insects that feast on nasty bugs that attack potatoes. Colorado potato beetles are a particular problem for potatoes. Among the plants that repel this damaging pest are tansy, coriander, and catnip. Potatoes are members of the nightshade family, so avoid planting potatoes near other family members, such as peppers, tomatoes, tomatillos, eggplant, and okra. This goes so far as to avoid planting potatoes where nightshade plants have recently been grown. 

These plants have the same genetics and are susceptible to the same diseases and insects. Follow crop rotation ‘Best Practices’ and allow two years before replanting members of the same crop family in the same location. Plants to Avoid Planting Next to Potatoes: Carrots, Cucumbers, Eggplant, Fennel, Okra, Onions, Peppers, Pumpkins, Raspberries, Squash, Sunflowers, Tomatoes, Tomatillos, and Turnips. 

 Good Companions for Potatoes: Alyssum, Basil, Beans, Cabbage, Catnip, Chamomile, Coriander, Corn, Horseradish, Lettuce, Marigolds, Nasturtium, Parsley, Peas, Petunias, Radishes, Scallions, Spinach, Tansy, Thyme, Yarrow. 

 Until next issue, I’ll be helping gardeners grow better potatoes here at Watters Garden Center. 

 Ken Lain can be found throughout the week at Watters Garden Center, 1815 Iron Springs Rd in Prescott, or contacted through his website at WattersGardenCenter.com or Top10Vegetables.com.