Peas, beans, and potatoes share growing requirements. Legumes can grow trellised to maximize space, and the potatoes will benefit from added nitrogen in the soil.
Corn has shallow roots that won't compete with potatoes, and planting them together maximizes space. It might even improve potato flavor!
Radishes are a great catch crop-- they'll be ready to harvest before the crowd out potato leaves. They're also a trap crop for flea beetles, which prey on potatoes.
Onions can help deter potato pests like potato beetles, flea beetles, and mites. Give them well draining soil and full sun!
Lettuce and spinach grow quickly in spring, so you can sow them as catch crops between potatoes to use the space while potatoes get established.
for 9 more companion planting ideas + what not to plant with potatoes