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Potting Soil Won’t Absorb Water
If your potting soil won’t absorb water, it’s possible that you have hydrophobic soil. Hydophobic soil repels water and instead of it soaking into the soil, the water will go down the sides of the pot and through the drainage hole. This can catch a lot of people out as you give your plant a big drink, you see the excess water drain away and you think your soil is fine. That’s why it’s so important to check the moisture of the soil to ensure the roots are getting sufficient water. If your soil is hydrophobic then this can be an issue as not enough water will reach the roots no matter how often you’re watering it and the plant can become dehydrated and eventually die of thirst, which we definitely don’t want to happen. If you think your soil might be hydrophobic, try inserting a moisture probe deep in the soil close to the centre of the plant to see how moist the soil is. If it’s staying quite dry after a watering then you have a problem.
Why Won’t My Potting Soil Absorb Water?
This can happen with soils that are heavy in clay as the mix can be too compact and it can be difficult for the water to move through the substance. Sometimes potting soil won’t absorb water if its old and has become too compact, this can occur with a soil that has been used a few times and has been left and allowed to dry out. Another cause of hydrophobic soil is when there is too much peat moss in the pot. Peat moss is a fantastic material but if it is left to dry out it can then cause a mixture to become hydrophobic.
How To Fix Hydrophobic Soil
If your potting soil won’t absorb water don’t worry, there are ways you can fix this. If your plant is dying of thirst you may want to consider taking it out of the potting soil that won’t absorb water and repotting it in a new mix while you solve the problem. That way the plant has the best chance of survival.
If you have potting soil that is hydrophobic but there’s no plant to worry about or you have a bit more time on your hand then there are other options you can choose from. Let’s take a look at a few here:
- A great option is to place your pot in a bowl or container of water where the water comes halfway up the pot. Then water your potting mix from the top, leave this for a while and then repeat. If you do this several times you should notice the soil absorbing water. This will be evident from the soil darkening and the pot becoming heavy but if you still aren’t sure stick a finger or a moisture probe deep into the soil.
- If you’re really struggling try working at the soil gently with a fork or chop sticks to create pockets of air. If you go deep be careful not to damage any roots.
- If your soil isn’t hydrophobic but water struggles to move through it then try adding perlite to your mix. Perlite aerates the soil and helps with drainage. The small pieces of volcanic stone help to create pockets of air that allows the water to move through. If you want to learn more about perlite take a look at our article: what is the white stuff in potting soil?
To prevent your soil from drying out in the future make sure you have a well balanced mix with perlite and that you don’t allow it to dry out in a shed somewhere. If you do have potting mix that had completely dried out then try moistening it again before you use it for potting a plant as you don’t want to shock you plant with dehydration or with dramatic reabsorbing attempts.
We hope we’ve managed to help solve the problem of ‘potting soil won’t absorb water.’ It can be an alarming thing to happen at first but like with many issues that come up with your plants, the quicker you identify them and find the cause, the higher the chance you have of saving your plant.
christopher hayward says
this is not due to ‘hydrophobic’ soil per se, but the phenomenon known as soil hysteresis, whereby the over-dry organic matter in soil repel water molecules due to the dipole to dipole bonding alignments of van der Waals forces and its interaction with dipoles found in the soil organic matter.
will some form of a wetting agent or soap mixed in water help with hysteresis?
So is there an easy fix for this? I have a garden box with tomatoes, beets and herbs, seems I’m just wasting water Because it just flows off the soil.
Water doesn’t go into the soil, it’s stays up for days, I try to turn it around with spade . Takes a while to dry up or even go into the soil. I need help please