Hydrophobic Peat

Horticulture
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I just want to share an observation and see if others have noticed similar phenomena. I was watering some landscape plants that were still in their nursery pots because the work was delayed. I noticed after watering thoroughly twice that the pots were still pretty light. So I got out a five gallon bucket and dunked the pots in water for 10 min each. They seemed heavier so I thought everything was good. 20 minutes later my wife decided one of the planting locations was ready for its plant so I dug a hole, removed the pot, and started breaking up the roots. A plant that had just been watered twice from above plus a 10 min dunk was almost entirely dry. None of the water made it anywhere near the core of the plant. I instantly decided that I hate peat and will never use it again. I should probably temper that reaction, but now I know what they mean when they say peat is hydrophobic once dried.

This is my first summer with plants in Akadama mixes and I’m surprised at how well they stay hydrated. Those plants are more “wet” than many of my things in peat mixes because the peat has such a hard time absorbing moisture. It seems the free draining bonsai mix has another huge benefit of also being freely accepting of moisture.

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Peat Moss needs to be hydrated before it is added to any potting mix, once hydrated it will absorb and hold a lot of water.
With the “dunking” method you would need to immerse the potted tree longer than 10 minutes. Was the pot trying to float? Did you see air bubbles being released?
Here is a link on watering Hydrophobic soils


You can try an emulsifier-a wetting agent- like dish soap, a few drops to a gallon of water. It will help break the surface tension of the water and allow it to be absorbed into the peat.
Good luck :grinning::evergreen_tree::metal:t2:

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I recently got a buttonwood that’s potted in some hard-to-wet soil. The heat here is running high. Until I get it repotted, I keep a soaking dish on hand. When the bubbles run out, I’m fairly confident that it’s soaked.

I’m with you on my dislike of dry peat.

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Thanks for the responses. I thought 10 min was enough because, while the plant started off floating and bubbling, it had sank and stopped releasing air.

It was a nursery plant in whatever soil they used. Now it’s in the ground so no big deal for that plant. Just a precautionary tale that even when the plant seems wet, with peat it can still be bone dry in the core. If I come across this again I will go longer with the soak.

How long can roots be submerged before they start to suffocate?

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I’ve dunked some trees for 15 -20 minutes, but it was also in soil that drained well afterwards. Dunno how well roots would do in peat that’s soaked to the core.

I can attest for the use of a little dish soap. A little bit added to the water and then watering slowly worked for me. I used a cop chopstick to make small holes in the soil ball, allowing the water to soak in from inside and not just the outside of the peat. It was a drawn out process though, and had to be repeated a few times before the peat was back to normal.

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