Can soluble salts affect your houseplants? What symptoms should you look for?
I was recently given a beautiful white flowering African violet.
As you can see, it is planted in a clay pot. What isn’t obvious, is the dead leaves under the healthy ones. Let’s discuss clay pots, soluble salts, and what they can do to your African violet leaves and other plants.
Clay pots and soluble salts
I love clay pots because they are classic, look good with all plants, and allow the plant to be the star of the show. I do use a lot of colored pots, too, though, because I love color.
Anyway, I digress…. The problem with using clay pots is the fact that soluble salts can build up in the pot and damage your plants. As you can see below, the African violet leaf resting on the edge of the pot is getting “burnt” from the salts in the pot.
What are soluble salts?
Soluble salts are minerals dissolved in water and often come from fertilizer residue. When the water dissolves after watering your plant the fertilizer residue remains. They can also come from your water source, such as well water.
Fertilizing is a good thing, though, right? Yes of course! Read the label, never using more than the directions call for. I use less.
Soluble salt damage
What kind of damage can you expect to see if there is a build-up of soluble salts in your potting medium?
Symptoms include stunted growth, wilting, and leaf burn on the leaf margins. Also yellowing new growth, small flowers, and reduced growth.
The spider plant is a popular plant that exhibits problems with soluble salt build-up. How many of us have spider plants with brown tips? Or other plants with brown tips and edges?
Soluble salt can cause root damage
Your plant wilts. You water it. Nothing happens. Why? The soluble salts build up in the soil and take moisture from the roots, they dry out and die.
The plant cannot draw up moisture if the roots are dead. It wilts and dies. This is often referred to as “root burn”. Dead roots and a dead plant are the worst-case scenario is the soluble salt build-up is high.
Clay pots and soluble salts
Clay pots are porous, meaning water evaporates through the walls. Plastic and glazed pots don’t have that problem.
If the water evaporates through the clay pot walls, the salts are also coming through.
As you can see below, the leaves touching the edge of the clay pot are dead. The soluble salts burnt the leaves snd stems and they collapsed.
Address the problem
So how can this problem be solved? In the case of the African violet in the clay pot, the first thing to do is repot the violet.
Plastic azalea pots are better for your violets. See the difference between a standard size pot and an azalea pot below.
Azalea pots are shorter than standard pots and violets have shallow root systems. Glazed pots are also fine.
After repotting, water the plant from the top, making sure it runs out of the drainage hole.
Many people bottom water African violets so as not to wet the leaves. It is okay to get the leaves wet as long as you use warm water because cold water will mar the leaves.
As the water rises to the top of the pot, the salts are also drawn to the top.
If drawn to the rim of a clay pot the leaves touching it die. If you bottom water your plants every time you must leach the soil every month or so. Run large amounts of water through the soil from the top, flushing any excess minerals out.
It is also a good practice to repot your plants using a fresh potting medium on a regular basis. You don’t have to put them into a larger pot but use new potting medium.
Remove the soluble salt residue
This can happen on pots other than clay but isn’t as bad, as the pots aren’t porous. If you see a crusty build-up on your plastic pots, take the plant out of the pot and scrub your pot.
The stubborn crust will come off easily after soaking your pot in vinegar. Wash and rinse well before putting a plant back in the pot.
Soak clay pots with a solution of 1 part bleach to 9 parts water. This is a good idea before reusing them on a normal basis.
Hopefully, your plants are all doing fine and no soluble salt damage is occurring. If you have had, or are having these problems, I hope this helps.
Have a great week, houseplant friends!
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I have two African Violets and I purchased those new pots that you place the potted plant into one bowl and that bowl is placed in a bowl with water and I guess the plant absorbs the water through the terra cotta pot??
Anyway, my plants are still mushy leaves at the base. What specific kind of pot do you recommend that I can plant into besides plastic?
Thank you very much,
So in the self-watering pot, you are saying they are staying too wet? The thing most people don’t realize is that if you wick water or use a self-watering pot, you need to have a potting medium that is well drained and doesn’t stay too wet. If you use a heavy potting medium, it will stay wet too long. If you don’t want to use plastic, you can use a glazed terra-cotta pot or cover the rim of a plain terra cotta pot with a sealant of some sort, so the salt buildup can’t affect the rim where your leaves are touching. Lisa
Thanks Lisa. Very informative, as always. The pics are very good.
My African violet plant has lower leaves that are full and healthy but the new top set of leaves are smaller, thicker, very bumpy. It sets a lot of buds but the flowers immediately wither and the stem close to the flower is dark . HELP!!!
Take a leaf from the bottom and maybe start a new plant in case this one expires. Can you send a picture to my email address?
Several of my African violets have developed small fluid filled reddish blisters on leaves and stems. This is particularly concentrated in the area around where stem and leaf connect although they may be anywhere along stems and leaves. These blisters are firm to the touch. If I break an effected leaf off, a cluster of blisters forms over the broken area still a part of the plant. Do I have mites, nematodes, or something treatable going on?
Sorry for the delayed response. Could you send pictures to my email Lisa@thehouseplantguru.com? I am in the African violet Society and I bet they would know.
My violets are in plastic pots and yet the leaves wilt where they touch the pot. Plants are huge and at least 20 years old
It can happen in any pot, but more often in clay. Maybe take your plant out of the pot and wash the pot and put your plant back in it. That way the salt residue won’t build up.