Asked on May 23, 2013

How do I seal clay pots?

by Cinda
I am attempting another year of gardening in pots. I would like to seal the pots without the risk of contaminating the herbs and vegetables. Anyone have suggestions?
Thanks bunches for your help :)
  14 answers
  • Tina Tina on May 23, 2013
    If you want to seal the inside i would use thick plastic bags for the outside i coat mine with spray acrylic sealer/finisher...i use one made by Americana...hope that helps.
  • Jane Jane on May 24, 2013
    Where to find the "sealer"? I had a spray can but used it all. Could not find this at Lowe's. Thanks for a clue--I do not like to waste gas looking all over town!
  • Bridget Bridget on May 25, 2013
    I used Thompsons Water sealer that I had leftover from sealing my deck.
  • KMS Woodworks KMS Woodworks on May 25, 2013
    Why do you think you need to seal these?...I have seen people run into more issues with root rot and over watering with "glazed" or sealed pots. The basic terra cotta pot will be cooler for plant roots due to evaporative cooling, they also allow you to monitor soil moisture levels more effectively. All paints sold in the US are food safe when painting the outside of them would be fine if you want to go that route.
    • See 1 previous
    • Aufbrezeln Eschaton Aufbrezeln Eschaton on Jun 13, 2019

      It takes a long time for water to erode the clay of a pot; the white stuff you see is mineral buildup. (Now, being left out through freezing-thawing cycles where they can get wet, that will get you a big pile of cracked pots in the spring, ask me how I know :/ ) Some plants love the airflow and drainage afforded by unglazed clay --- anything from a Mediterranean climate, and especially succulents (for beginners), I strongly suggest unglazed clay.

      But my African violets, cyclamen, mandevilla, most of my tropicals, really --- anything that wants to stay "moist but not wet" --- they get plastic or glazed clay/ceramic, because they *want* the water retention. (It is perhaps even more important to make sure that these plants get well-draining soil with lots of perlite or grit, as even the most water-loving plants still need oxygen to their roots.)

      Choosing the right pot and soil for the particular plant can be the most important factor in that plant's success this season. If the plant's needs are "fast-draining," if they tell you to let it dry out between waterings, these are indications that unglazed clay will do beautifully. If it has that magic "consistently moist" requirement, though, you want something non-porous.

      Regardless of which type, it's important when watering containers to thoroughly drench, until water runs out the bottom. Otherwise, minerals from your water can build up in the soil and block the roots from getting what they need. This also means that you need to fertilize more frequently, as the nutrients get washed out more quickly.

  • Jane Jane on May 25, 2013
    I have found that the clay pots need to be sealed. I have some pots that did not have the proper seal and all the paint inside and out peeled off. Today I found a small spray can of "clay pot" sealer. The sealer is not the same formula as Polyurethane. The final seal to keep the paint on the outside needs the poly. Rot root, I think that is due to over watering. However I am still searching for the sealer as I bought the last spray can of the proper sealer at Hobby Lobby today.
  • KMS Woodworks KMS Woodworks on May 26, 2013
    Jane, I can see where you might need to seal them if you are going to paint...but for a simple gardening project leaving them in their natural state will allow them the "breath" and be far less work and expense.
  • Michelle Eliker Michelle Eliker on May 26, 2013
    Cindi, the only clay pots you need to seal on the inside are unfired clay pots ( usually from Mexico) that will break down over time - and I wouldn't recommend those for growing food anyway.
  • Cinda Cinda on May 26, 2013
    Hey ladies, thanks so much for your suggestions. I appreciate all of your wealth of information.
  • Caley's Culinaries Caley's Culinaries on May 26, 2013
    From a gardening point of view, some plants like lavender and rosemary will die if you seal their clay pots. They need to have porous material for drainage. Anything soft and green won't mind glazed or plastic or other waterproof material.
    • Aufbrezeln Eschaton Aufbrezeln Eschaton on Jun 13, 2019

      "Tropical" = non-porous. "Mediterranean" = porous. I know a lot of cacti enthusiasts tear their hair out over the admonition to put succulents in unglazed clay, but for beginners, I think it's perfect. You can keep Mediterranean-climate plants in plastic or other non-porous pots, but it's super important to have a really, really well-draining soil and to let their soil dry almost completely before watering. They'll survive a wilt or two much more easily than being soggy.

  • Tina Tina on May 26, 2013
    @ Jane Menges if you have access to a Michaels Craft Store or a Hobby Lobby you can find the sealer there...:)
  • Jane Jane on May 26, 2013
    Hmmmm! Thanks for the comments. I plan to do research on the clay pot painting and sealing. This is the first time I am gardening in "plastic long narrow containers". We want some fresh vegies to eat. I have always managed to have a garden where ever I have lived. There must be an authority, with experience, that can add to this subject. Let us hear from you please.
  • Pat Pat on May 26, 2013
    Your state Cooperative Extension Service or Extension Agent should be able to advise.
  • Linda Hunt Linda Hunt on Feb 23, 2017

    I am also curious because I want to use them for non-food items and for very low level of water required succulents so it will not create a water stain on wood. Thanks to anyone who knows t

  • Rolan Echavez Rolan Echavez on Aug 13, 2020

    Is there a food grade sealer for clay water jars?