What Makes a Plant a Weed?

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There is no weed family in biology.

A botanist can tell you a plant's family and its name, but nothing in it says weed. That word describes what a person thinks of it.

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The same plant swaps sides depending on the field.

Wheat growing in a barley field is a weed. Mint in a border is a menace and mint in a pot is a herb.

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Still, the plants we call weeds tend to share a few habits.

They grow fast, set seed early, make an enormous number of seeds — a single fat hen plant can set tens of thousands. And they thrive on bare disturbed ground, which is exactly what a garden or a field is.

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And many can come back from a scrap left behind.

Break a dandelion root and each piece can grow a new plant. Bindweed and couch grass do the same, which is why digging can spread them.

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So weeding is gardening, not biology.

You are not removing a category of plant. You are deciding what grows where, and the plants are simply very good at the ground you keep clearing.

Several plants sold in supermarkets — dandelion leaves, nettles, purslane — are weeds somewhere else in the same week.