Douglas fir saw dust mulch for fruit trees

I have plenty of Douglas fir saw dust leftover from blueberry mulching. Can I use this to mulch around fruit trees? is it going to make the soil around them too acidic? I have been mulching with wheat straw currently but those wheat seeds are relentless.

It will bind nitrogen until the saw dust completely breaks down. I would not hesitate to use sawdust for mulch, but have a plan to maintain soil nitrogen levels. Wheat straw does the same but breaks down so fast that the nitrogen balance is relatively unaffected. Saw dust takes months to years to break down.

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Sawdust will sometimes form a hard crusty matt that then becomes hydrophobic and sheds water away. It’s easily resolved by breaking it up a bit with a hoe or fork. Just something to look out for. I use saw dust from the mill to stool root stocks. Pine chips and pine saw dust won’t change your pH.


Aside from your worry about pH, does sawdust actually make a good mulch?

I’m a bit skeptical. I want mulch to stay in place, and given a good wind gust, I just see the dry saw dust being blown away. Same reason I don’t like using leaves as mulch either, it gets too easily eroded by wind.

It’s working pretty good in my blueberry beds.

Do you apply the sawdust mulch wet or dry? What happens to saw dust that gets wets and then dries? Does it stick together to each other? Sounds like that’s what @AndySmith is saying. Maybe in that case, it’s similar to peat moss.

I didn’t think much while applying, I just mulched and its has held in its place - probably due to rains in PNW. But, we’re having a heatwave for last week and it’s still in place, I guess the drip line keeps it from blowing away.

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“When you use low-nitrogen organic materials for mulch, such as cypress mulch, wood mulch, pine bark mulch, pine straw or fallen leaves (oak leaves make an excellent mulch), nitrogen tie-up is not an issue. The organic matter is applied on top of the soil and interacts with only the very surface of the soil. It decomposes slowly at the surface without affecting available nitrogen levels down in the bed.”

If you watch Mike Kincaid’s videos on youtube he grows just about everything in fir bark mulch. Some plants exclusively in it.

Talking about woodchips/mulches/saw dust always ends in a debate… if it works for you keep doing it… if it doesnt then do something else. Reading about it is just confusing…and debating about it is futile.


No one here is debating whether adding organic and woody material is beneficial. Just trying to learn from each others experiences, specific to saw dust format.

I have a 40 foot x 10, apple espalier I mulched it two years ago with pine/fir sawdust. Six inches deep. No problems whatsoever. The trees are nice and healthy. As long as you don’t dig it into the soil and it sits on top of the soil there will be no nitrogen problems. Here is a not very good photo.


Better picture.


Are my eyes deceiving me, or does that sawdust looks rather chunky?

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ive used sawdust for years with 0 issues. this was chainsaw sawdust not the fine stuff from a woodworking shop. doesnt affect N in soil unless you turn it in.


great, thank you.