By Larry Hodgson
Question: I saw on Facebook that you could grow new carrots from carrot tops. The claim is you can cut off the top of the carrot, root it and grow a new one. That somehow doesn’t seem likely to me. Am I missing something?
Answer: You’re not missing anything. It’s yet another bit of misinformation being widely shared on social media, as if there wasn’t already enough bad gardening advice circulating!
You often see this offered as a project for children. You cut off about the top 1 inch (2.5 cm) of a carrot, place it in a bowl of water and soon white roots appear and new leaves start to grow. But no “carrot” (thick orange taproot) ever forms. And there’d be no place for a taproot to grow in a bowl of water at any rate.
Even if you planted the carrot top in soil—and one variation on this technique is to plant the carrot stub in a pot of soil—, it still would only produce secondary roots and leaves. For a carrot plant to form a taproot, you have to grow it from seed… in deep soil.
Do note that carrot leaves are edible and if you want to grow carrot tops for their edible leaves, go for it! (Do make sure to give the rejuvenated plant plenty of light!) But you can’t grow an edible carrot taproot from a carrot top.
The same applies to beets, parsnips, turnips and other vegetables mostly grown for their thickened taproot. You can also grow their tops for edible foliage, but none will produce a new taproot once the original one has been removed.
That said, you can legitimately grow such vegetables as romaine lettuce, bok choy and celery in a bowl of water or pot and turn them back into full-fledged veggies by rooting the bottom of the vegetable, not the top. You can read more about that in the article Leafy Greens From Kitchen Scraps.