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Why you should not place TreeDiaper on top of mulch

Posted August 22, 2022 by Dr. Wei Z

Many people use TreeDiaper® like a watering bag by placing it on top of the mulch. That is not right.

This simple demonstration uses napkins to simulate the soil and wood branches to simulate the mulch. It has two parts. The first part is about keeping soil wet, the second part is about keeping soil from getting too wet.

Part I: TreeDiaper® treemat release water to keep soil wet

Part II: TreeDiaper® treemat absorbs water back up to prevent soil getting too wet

Will TreeDiaper® cause overwatering problem? 

Quite the opposite. 

When used properly--meaning placing right on top of the soil, not on top of the mulch--it would absorb water up to reduce overwatering problems. I transferred the napkins into a shallow tray and continued the experiment. The follow-up demonstration is to place this setup in a shallow tray and add excess water to it. 

As you can see, the standing water was absorbed up by TreeDiaper® treemat when it was placed onto of the soil. At the same time, there is almost no change in the standing water for the tray with mulch. 

When the standing water is higher than the mulch layer and in direct contact with the bottom of TreeDiaper®, TreeDiaper® treemats should be able to pick up some of the excess water. This excess water would otherwise wasted as runoff. With TreeDiaper® technology, this otherwise wasted water can be used at a later time during a dry spell.

How does this work? These videos on youtube explain the mechanism:  

12 minute in-depth:

5 minute brief:

1 minute speedy with a case study in Houston:

I have people asked me why some TreeDiaper® treemats in the pictures on your website appear to be placed on top of the mulch. They were taken several years ago. And it is a dilemma for us between what is right and what is to show on the website. After all, we are not a manufacturer or a distributor of mulch products.

"TreeDiaper® is awesome!! My new trees look great and it makes watering so easy and reliable! I highly recommend them!"

- Julie D, Happy Customer