When you buy vegetables at a farmers market, often you will get root vegetables (e.g. potatoes, carrots) that are unwashed and with its dirt still clinging on them. I heard somewhere that this will prolong its shelf life. Is this true? If so, how?

4 Answers 4


Not really, the dirt's there because of:

  1. Authenticity: dirty veggies make people think "garden-fresh"
  2. Laziness: farmers don't want to spend much time cleaning their vegetables

Washing to remove dirt won't shorten the shelf life, but mechanically removing dirt (as in with a hard brush) might in some cases as it could remove or puncture skins or peels.

  • It's a bad sign! A farmer that doesn't want to keep their dirt is lazy, and runs a bad business, they may also be hiding bad quality produce under a layer of dirt. Freshly picked and washed vegetables should be clean, and last as long, if not longer than unwashed.
    – TFD
    Commented Oct 12, 2012 at 11:04
  • 1
    dirt is much more likely from heavier ie clay soil rather than sandy loamy. My carrots often have little sticky mud patches whereas my green onions have a dusting of sand around the roots. I prefer cleaning veg myself rather than the agricultural (tainted) water of veg packers.
    – Pat Sommer
    Commented Oct 15, 2012 at 5:14
  • if the produce are not good quality, then the farmer will get out of business whether it is selling clean or dirty vegetables.
    – Max
    Commented Mar 23, 2016 at 13:13

From what I have understood, at least potato farmers prefer to store potatoes "dirty" ,mostly because the soil/clay will help protect the surface of the potato and keep it from dissipating moisture.

If you think about it, the natural way for wintering a potato (or a root vegetable) is for it to stay in the ground, in soil and wait for the next spring. So the best way to store a harvested potato , is to keep it in earth-like temperature and humidity.

Also to add one point I just realized. Soil will probably stabilize the moisture by capturing/releasing it to avoid formation of drops of moisture, which will probably stop fungi and mold from getting hold.

  • 1
    A wet vegetable is a vegetable in danger of growing mold or bacteria. If you choose to wash the things, be sure the end product is dry. Commented Nov 25, 2018 at 0:22
  • 1
    yes, but the problem is that stacked, washed root vegetables will gather moisture somewhere and then mold growth starts. If you ventilate them well enough, they will not grow mold but they will dry up faster. soil will stabilize moisture to prevent this. Commented Dec 2, 2018 at 22:46
  • Can't disagree with that Markus. Potatoes seem the worst offender. One week you pick up a nice dry bag. The next week a third of those nice tates have turned into horrible smelly liquid. Commented Dec 2, 2018 at 23:10

I leave the dirt on my veggies but not to prolong their life. I compost peelings, and when I peel without washing first, that dirt goes in the compost. When I wash first (perhaps weeks before I use them), the dirt goes in my septic tank, which doesn't help my garden.

Occasionally I will buy veggies from the supermarket and they are always pristine. They do not spoil faster than the from-my-farmer veggies with a little dirt on them. This could be because any that get scratched or bruised in the washing process are thrown away before reaching the store. But it shows there is no property of the clinging dirt that extends storage life. As long as you wash them carefully there should be no problem. But there's also no compelling reason to wash them earlier than you need to.


Definite don't wash. In pre- supermarket dats no veg's were washed and you could keep them all through the winter if stored correctly. Nowadays, they wont keep a week, plus a lot of there natural flavour has gone. I dread to think whats growing on them inside the plastic bag in the fridge, urghhh,!!Providing fresh unwashed veg are kept cool and frost free, in the dark you will have no problems at all.

  • 2
    Could you provide some references for these claims? Commented Mar 23, 2016 at 12:19
  • 3
    It would be interesting to store a washed and unwashed root vegetable side by side in the fridge and see what the results with. But without an experiment like that, your answer just reads like one guy's opinion on how modern food is going downhill...
    – Erica
    Commented Mar 23, 2016 at 15:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.