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March 16, 2021

How to Remove White Residue From Terracotta Pots

Terracotta pots give the most beautiful earthen look and feel to your plants. The additional advantages of these pots include being natural, porous, and absorbing excess moisture from the soil, which improves your plant’s overall health. However, after a while, terracotta pots develop white residue. In this post I will explain the reason behind this residue and quick, easy methods to clean terracotta pots.

Terracotta pots give the most beautiful earthen look and feel to your plants.

1) Hard Water Deposits

One of the reasons the white spots appear on your pots is when you water the plants with hard water (tap water in most places). Hard water contains salts and minerals such as calcium. As the water evaporates, these soluble salts are left behind as a white residue. It is similar to the white crust left on your shower head.

2) Fertilizer Leftover

If your tap water is not hard, your soil fertilizer is the likely cause of the white residue. Fertilizers contains minerals. Since terracotta pots are porous, the minerals seep through and are left behind when the water dries off.

Can I leave the residue? Is it harmful?

I know many people love the old terracotta look. I agree, it can look amazing 😊 However, buildup of salts can damage plant roots. What you could do to keep the beautiful terracotta look and protect your plants, is clean the deposits from the inside of the pot, while leaving the beautiful outside look.

Can I clean the pot with the plant inside it?

Before applying any cleaning method, I suggest carefully remove the plant from its pot together with all the soil. After you’re done, you’ll be able to put it back in with the whole rootball intact.

I don’t recommend leaving the plant inside during the cleaning process as you won’t be able to clean the part that matters, the inside of the pot, and also, some of the cleaning solutions can damage the roots.

Cleaning Method 1 – Cleaning With White Vinegar

Using white vinegar is a cheap and straightforward way to clean terracotta pots. The mixture ratio is 1 part vinegar to 20 parts water. Soak the pots in the water/vinegar mixture for about 30 minutes, giving vinegar time to start dissolving the deposits. Scrub the inside, outside, and anywhere you find the white spots.

This solution is safe to be used in the dishwasher if you can fit your pots inside! Set the dishwasher to maximum heat and the strongest water spray settings.

After you’re done, regardless of whether you used the dishwasher or manual cleaning method, wash the pot again, but this time using plain water. Get the vinegar out of the pot.

Cleaning Method 2 – Cleaning With Bleach

Another method to clean terracotta pots is with household bleach. The mixture ratio should be 1 part bleach with 20 parts water. If your pot size is small, you can dip them in the solution for faster removal of the deposits. Otherwise, scrub the pots with this solution. After cleaning, soak the pots in clean water to remove the remaining bleach. Let the pot air out for a few days, so the smell of bleach is completely gone before using it.

Preventing Mineral Deposits

1) Leaching Soil

To prevent white spots on terracotta pots, leach the salts out of the soil every few weeks. Sometimes a thin white layer of the salts and minerals is visible on the soil. You can remove this top layer. Then thoroughly soak the soil, make sure all of the soil is wet. Leave it for 10-15 minutes, give the time for soluble salts to start dissolving in water. Then, place the pot in a sink or a tub and start pouring water into the soil. Let the water drain out the bottom to flush the salts. Repeat the process several times. Each following time the color of the water coming out will be lighter.

A buildup of salts can damage your plant, so it is good practice to flush the soil regularly, every couple of weeks. This method is tested and very effective.

2) Use Rain or Distilled Water

Although the ideal solution to this problem would be to remove minerals, plants needs them for growth and development. Instead, you can try decreasing salts by watering plants with distilled water or rainwater. Distilled water and rain water contain no minerals. If you have a reverse osmosis water filtering system in your home, you could also use the water treating with it for watering your plants. A reverse osmosis filter removes 70-99% of minerals from water. This is the system I’m using in my home.

Share this post with anyone else worried about how to clean terracotta pots and keep their plants healthy.

Yours Truly,

Mr.Houseplant-signature-tr

8 Comments

  1. Annette Demarest September 16, 2021 at 12:17 pm - Reply

    Thank you for this, really useful – I bought two really nice large terracotta pots, one I varnished on the inside, the other I did not. The one I did not varnish has all the residue, I have emptied, washed, treated with your vinegar tip! thank you ! then will varnish – like the other one…

    • MrHouseplant September 17, 2021 at 7:25 pm - Reply

      My pleasure Annette, glad it was helpful :) I spray painted some of my terracotta pots. It does provide a great look and you won’t need to clean them, but I’m sure you know they will not be porous anymore, they will be like glazed terracotta now. Which means the soil will stay wet longer, which is fine if your plants can handle it – if they are getting enough light and the potting mix is porous enough :)

  2. carole Famiglietti January 5, 2022 at 5:33 pm - Reply

    Thanks for your helpful info. My pot, which is quite haevey, has had a plant in it for about 15 yrs or so. The plant is thriving, even thru some problems. I know you cannot clean pot with plant inside, but I cannot remove it. Is there something else I can do to clean it? I have been using a wet paper towel with a touch of dish detergent.
    Thanks for your help.

    • MrHouseplant January 5, 2022 at 5:48 pm - Reply

      Hi Carole,

      Is the plant too big and heavy to be removed? I use a repotting rake to separate the plant and soil from the edges of the pot, take it out, clean the pot and then put the plant with the soil back in. Plants that have been in soil for so long will usually have the rootball and soil pretty compact and can be pulled out as one piece, without the soil crumbling.

      If the plant has been in the pot for so long, I do recommend repotting it eventually, it will benefit in many ways. I wouldn’t recommend a full report but just a pot up, or at least just adding an inch of soil on the top to provide some additional nutrients, although that will not help with soil compaction and oxygen for the roots, but it will be safer.

      If you can’t take the plant out, try spraying the outside of the pot with vinegar, leaving it for a while, and then washing it off with water. You could use a turkey baster to remove water and vinegar from the saucer.

  3. terracrafts February 19, 2022 at 9:49 am - Reply

    Thank you very much for sharing this awesome information. this is very helpful.

    • MrHouseplant February 19, 2022 at 7:46 pm - Reply

      You’re welcome, I’m glad it’s been helpful

  4. Louise April 15, 2022 at 3:31 pm - Reply

    what do you use for varnish

    • MrHouseplant April 16, 2022 at 4:41 pm - Reply

      Hi Louise, are you looking to apply varnish to terracotta pots or to remove it?

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