Murderous mulch

The mulch around the base of this tree is more than 12" above grade and is a typical of example of how mulch can lead to a plants decline. Photo by Doug Freer.

As a longtime landscaping professional, I am often asked "What's the best way to kill my plants?" Well, there are a lot of answers to that, but few techniques offer more paths to certain plant death than extreme mulching. Just follow these mulching tips. Don’t be disappointed if you don’t kill them right away. Your stunted and unhealthy plants may just be exerting their will to survive - but eventually they will succumb.

1) Be cheap and undiscriminating. Anything labeled “mulch” should do the trick, no matter where it comes from. Look for the least expensive mulches. Raw mulch, which has not been aged or begun to decompose is best. Raw mulch readily draws nitrogen from the soil and will do a swell job of "burning" tender plants. Fully composted and aged hard wood bark mulches, leaf humus or other organic compost materials like SweetPeet, however, will actually benefit the plants, so be careful!

2) More is better. If some is good, then more must be better. Be sure to add two inches of fresh mulch every year regardless of how thick the layer becomes. Never rake it to loosen it and air it out. If you really want to kill your plants, the last thing you want to do is let in any oxygen or moisture to the root system. Mulching with two inches of fresh mulch every year not only looks fancy, but will be sure to reduce oxygen to the root system, prevent moisture from getting into the soil, or trap excessive moisture in the bed causing root rot.

3) Pile it on. Another great way to increase plant mortality is to pile mulch against the base of trees, ornamentals, and perennials. Mulch volcanoes are the latest rage and are a sure way to encourage girdling roots in woody plants. Bark is effective at protecting the plant when it has light and air, so be sure to keep the bark dark and moist in order to invite insects and disease. Beware: the “two finger rule”--keeping mulch and soil two finger widths away from the trunk or base of your garden plants--it really works, and it may confound your plans to kill everything.

4) Mulch early. Mulching early in the spring before the beds have dried out is a great way to trap soil moisture and cause root rot.

5) Use weed cloth. Either plastic or fabric weed barrier cloth not only provides that extra little protection against weeds, these “burial” cloths, I mean barrier cloths, also contribute to perched water table problems.

As I say, there are other are other means of undermining your garden's health, but mulching has the advantage of being very popular, so you can even kill your plants while appearing to take care of them.

Douglas Freer is a Cleveland Heights native and the owner of Lawn Lad, Inc. Lawn Lad provides residential landscape services in the Heights area. Call 216-371-1935 or visit

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Volume 2, Issue 5, Posted 5:45 PM, 04.22.2009