Turnip vs. Radish: What is the Difference?

What's the difference between a radish and a turnip? Unfortunately this is not the setup for a joke (but if you think of a good punch line please send it to me). Like the age-old language vs. dialect question, or which animals count as different species, the differences are real but the boundaries are somewhat subjective. Plant species is a bigger category than what we normally think of as a particular vegetable, for instance turnips are Brassica rapa, but so are napa cabbage, bok choy, mustard greens, and a bunch of other stuff. Brassica oleracea is one species that includes cabbage, cauliflower, broccoli, kale, collards, kohlrabi, and Brussels sprouts. Radishes are Raphanus sativus, which includes the little red radishes that we bunch, and all kinds of daikon (which can be white, red, purple, or green). So the names we commonly use like "broccoli" or "kale" are smaller categories than species, and then smaller than that are the seed varieties (often called cultivars, which is a weird mashup of "cultivated varieties"). For instance Toscano kale is the dark green flat kind, and Winterbor kale is the light green curly kind, and those are the names of the specific seeds you would buy if you wanted to grow those particular crops.

All this is to say that while a purple-top turnip may not seem very different from a daikon radish, they are in some ways more different than cabbage is from broccoli or kale. Or you could say that a turnip is closer to salad mix than a radish. This seems a little weird when you see (or eat) the harvested end product, but it's clear when you're on the seeding end. Seeds of the same and related species and often very similar looking if not identical. Carrot seeds look a lot like fennel seeds, and cucumber seeds look a lot like watermelon seeds. But radish seeds are many times bigger than turnip seeds and differently shaped, requiring totally different settings on our seeding machine, and turnip seeds are small and round like mustard seeds (and are indistinguishable from seeds for kale, cabbage, broccoli, etc).

Photo Source: https://www.realsimple.com/turnip-vs-radish-11777908