My parents' garden is circled by a massive hedge of cypress. When they bought it 10 years ago, it was completely unkept, and over the course of the years my dad has been trimming the cypresses more and more until the hedge looks somewhat clean. Now, each year, he takes a week to trim the cypresses, and I often help him. However, we have an issue: how do we take care of cypress leaves? By leaves, I mean, what's left when we trim the trees (needles, bits of branches, etc. It is full of resin, sticky, and acid).

We thought of just spreading them around in the garden, but the leaves are very acidic and we have been told that they can prevent the growth of other plants. It's easily noticeable in our garden, very few plants grow under the hedges. Since the leaves take several months to degrade into mulch, we're afraid it would ruin the garden if we did that every year.

At first, we used to burn them. But since a few years, to prevent fires, our region has made it completely illegal to burn things in your backyard unless you're a private company.

We also can't bring the leaves to the waste treatment faculty, because we would need a huge trailer, and we are limited on what we can bring each year. Besides, it's a paid service and my parents aren't too keen.

So, this year again, we end up with a big pile of resinous leaves, that we can't do anything special with. Last year, my dad found a temporary solution: we chopped them into tiny bits using a lawn mower with an adapted blade (they are much too sticky for our tree/branch shredder). Then, we disposed of the small, dried up bits under the hedge. But they don't decompose into mulch, and they're accumulating there.

One year, we also tried leaving them in a big pile until they dry so we can use them as firewood (for the fireplace), but they make terrible firewood (they produce a real lot of smoke), and everything that was under that pile died because of the shade + acidity.

I have thought of something but I haven't found anything online corroborating this idea: can we mix them with fireplace ashes to neutralize the acidity? Every week, our fireplace produces a lot of white ashes. My dad simply gets rid of it by spreading them in the garden or temporarily storing them in big bags. Since ashes are very alkaline (I think), couldn't we just spread them on the chopped up cypress bits to neutralize their acidity? And then chop everything down, and use it as mulch.

Here is a summary of the things we have tried:

  • burning them, we can't do that anymore
  • making a big pile, kills what's underneath (and what do we do of the pile then?)
  • chopping them into mulch and discarding it under the hedge, but it's not optimal.

We're a bit lost. Do you have any idea or a solution for this problem? Many thanks.

1 Answer 1


Wood ash would indeed neutralize acidity, but you need to mix them and some water may be needed.

If you have disposed of wood ash by spreading it in your garden for a prolonged time, it has altered the soil pH and made it alkaline. You can spread the leaves where you have previously spread wood ash to decrease the alkalinity of the existing soil.

Also, if you can, you can dig a hole at one part of the garden and dump the cypress leaves there to turn it into compost. Since the cut leaves are produced yearly in your home, there is sufficient time for it to decompose and become compost. You can mix your wood ash in this compost pile, and that will neutralize the acidity faster than it takes for the organic acids to decay naturally. The resulting compost will be neutral in pH. You can then use the compost on other trees in your garden as fertilizer.

  • 1
    Wouldn’t the resulting compost be too acidic as well?
    – Fred Rocha
    Jan 25, 2022 at 21:54
  • 2
    Being organic, this acid would degrade with other organic compounds. The end result would likely be mildly acidic though after a year.
    – joy
    Jan 25, 2022 at 22:18
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    Very good, thanks! I shared it with my dad. I'll leave the question open for a moment in case someone else wants to chime in, then I'll validate. Thank you again, this is probably what we should end up doing! (Mixing the leaves with wood ash and water, and leaving them to compost)
    – C. Crt
    Jan 26, 2022 at 14:09
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    That's a very good point! Mixing the ash in the compost pile will neutralize the residual acidity, and the compost will end up neutral. I am editing this answer and adding this.
    – joy
    Jan 26, 2022 at 14:34

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