Potatoes can spread disease to similar family or other root crops when planted consistently immediately after. Basically the same pests/ diseases that like the potatoes are then given a buffet of similar plants to continue munching & reproducing. These plants may also require the same nutrients (as is case with tomatoes & Potatoes)
Planting a different family /non-root crops with different nutrient and pest concerns in the same space is fine. There are many articles on crop rotation that would cover this (ex.
https://www.thespruce.com/companion-plants-for-potatoes-2540039) . Depending on the length of your growing season you may even be able to get some cool-season leafy greens for the fall.
