Fresh pine wood slices, suitable for mulch?

[Phoenikakias]

Due to heavy snowstorm during past February many pine trees in the public parks of Athens broke or split in to half and workers have chopped them down entirely for safety purposes. Many branches were processed through a shredder. Now thera available everywhere large heaps of pine wood slices. Are they suitable for mulch or are they still to fresh to this purpose, given also the resin contained?

Edited June 16, 2021 by Phoenikakias

[Tyrone]

Pine mulch should be aged and composted before being used as a mulch. Freshly chopped pine mulch will cause nitrogen draw down as microbes use up nitrogen to try and break the mulch down. 

[Steve Mac]

Tyrone is right, although that is not always as important to a deeply rooted palm as it is to vegetables for instance. 

Fresh pine chip is also acidic and depending on your soil if used often can leach deeper and may need to be balanced with ash.

However I have used it on a few occasions with no obvious problems around big plants and on walkways.

Oh, and it will inhibit seedling growth.

[Phil Petersen]

16 hours ago, Tyrone said:

Pine mulch should be aged and composted before being used as a mulch. Freshly chopped pine mulch will cause nitrogen draw down as microbes use up nitrogen to try and break the mulch down. 

This potential nitrogen drawdown is something that I have read up on a lot from various sources and talking to other gardeners. I have esablished a food forest with a deep mulch system and wanted to be sure i wouldnt deplete all the nitrogen. They key is to only apply the wood chip mulch on the surface and not mix it with the topsoil at all. Burying woodchips into the topsoil layer at all is no good (not sure why anyone would do this). But use of fresh arborist chips on the surface as mulch will have no ill effects on nitrogen as it cant draw up nitrogen out of the soil except for a tiny fraction at the surface. It will improve and nourish the soil as it breaks down. 

[tim_brissy_13]

6 hours ago, Phil Petersen said:

This potential nitrogen drawdown is something that I have read up on a lot from various sources and talking to other gardeners. I have esablished a food forest with a deep mulch system and wanted to be sure i wouldnt deplete all the nitrogen. They key is to only apply the wood chip mulch on the surface and not mix it with the topsoil at all. Burying woodchips into the topsoil layer at all is no good (not sure why anyone would do this). But use of fresh arborist chips on the surface as mulch will have no ill effects on nitrogen as it cant draw up nitrogen out of the soil except for a tiny fraction at the surface. It will improve and nourish the soil as it breaks down. 

I’ve read the same thing. I think there have even been studies which confirm this. A thick layer of mulch without mixing into the soil layer will do a lot more good than harm. 

[sonoranfans]

If it smells like turpentine, let it age and lose some of the terpenoids first.  These are water repellent and inhibit bacterial and fungal growth.  In time that will change as the terpenoids age, evaporate and are oxidized.  At that point bacteria and fungi can grow and you can spread it.  Plant terpenoids have many functions some like eucalyptus oils can be herbicides.  Pine oils will have growth inhibitor terpenes that limit essential soil microbes.  I also agree with acidity being an issue, pine needles are the most acidic part of the tree.  I would fertilize before you lay the cured mulch to prevent nitrogen fixing.  A few months later this should mostly subside when you put down the next fertilizer treatment.

[teddytn]

19 hours ago, Phil Petersen said:

This potential nitrogen drawdown is something that I have read up on a lot from various sources and talking to other gardeners. I have esablished a food forest with a deep mulch system and wanted to be sure i wouldnt deplete all the nitrogen. They key is to only apply the wood chip mulch on the surface and not mix it with the topsoil at all. Burying woodchips into the topsoil layer at all is no good (not sure why anyone would do this). But use of fresh arborist chips on the surface as mulch will have no ill effects on nitrogen as it cant draw up nitrogen out of the soil except for a tiny fraction at the surface. It will improve and nourish the soil as it breaks down. 

When palms grow in a forest setting naturally, all the trees drop leaves, twigs and branches and mulch the forest floor. 

[Palmfarmer]

How come some people use woodchips mixed in with their potting mix for planting in pots. I got 2 trachies in a mix of black soil and woodchips and them do well so far. Bananajoe also uses this mix.

[Swolte]

You are fine to use them as mulch. In fact, the sooner you use them the better it will likely be. The idea that they have a big influence acidifying the soil or draw nitrogen (as long as you don't till it into the soil) are myths that have been busted. Most university extension services are now also distributing this news. Find good sources on the web.
:)

[amh]

Check for any allelopathy with the species first, but I wouldn't hesitate to use pine as mulch.

[Phil Petersen]

5 hours ago, Palmfarmer said:

How come some people use woodchips mixed in with their potting mix for planting in pots. I got 2 trachies in a mix of black soil and woodchips and them do well so far. Bananajoe also uses this mix.

Im not sure to be honest. What I do know is that most premade potting mixes (including the exoensive ones) will have many bits of wood in its composition in various stages of decomposition.  It must be a good thing. Ive imported many truck loads of arborist chips onto my 1/4 acre to apply on top of the otherwise heavy basalt clay soil, improve carbon levels, and improve drainage. The worms and other soil creepy crawlies love it and its teeming with life.  Ill take all the woodchips I can get my hands on!

[Swolte]

13 hours ago, Palmfarmer said:

How come some people use woodchips mixed in with their potting mix for planting in pots. I got 2 trachies in a mix of black soil and woodchips and them do well so far. Bananajoe also uses this mix.

I am not sure there's a clear answer for this one but my guess is that it doesn't really matter:
1) These mixes often they use pine bark or a bark that does not break down easily so the idea would be that they improve drainage. I can't see a reason why having large chunks of bark would improve drainage. Its the same myth as folks thinking that adding big rocks would improve drainage. Other than reducing soil, I don't see a large disadvantage either though. 
2) As for those chunks reducing nitrogen and adversely affecting grows:  these potting mixes have no shortage of nitrogen at all, in fact, they are supercharged on it to an unrealistic amount. 

I could be wrong but to test this, scientifically, we would need to grow 100+ palms with and 100+ without the woodchips in a potting medium and compare after 10 years. To my knowledge, no such studies exist. Research isn't cheap or easy and I can't recall experiments like which are ran (they should!).   

Edited June 18, 2021 by Swolte

[teddytn]

The healthiest palms I’ve ever seen growing in pots at least were in a mix full of wood chips. This may be a step too far for this thread, but ties in I believe. The trend to move back to organic agriculture was long over due, chemical growing practices have been proven time and again to harm the soil and produce fruits and vegetables that are less nutritious than the organic equivalent and the plants themselves are highly susceptible to disease, hence the need for more chemicals to correct these problems. So if you’re with the idea of growing plants in general organically, palms being a plant, then feeding the soil and the soil feeding the plants is the way to go. In my limited experience using wood chips as mulch is top of the list of easy things a human can do to benefit plants in ground (succulents and cacti excluded). Easy experiment anyone can do to test this, put a 4” thick layer of wood chips anywhere on the ground, come back a month later and peel the mulch back and let your eyes convince you. In my experience every time I pull mulch back it’s teeming with life, worms, snails, all types of crawling insects. Not to mention all the life not visible to the naked eye. Also what should be visible are tons of long strands of mycelium, the fungal workforce out of sight helping plants where they need it most. So let’s say the wood chips are “taking” some of the surface level available nitrogen for decomposition….what about the plants roots that are inches or feet below the soil surface? Does the wood chips decomposing on the surface affect available nitrogen underground? Not likely. Even if it did, the mycelium is in search of the nutrients the plant needs to trade for sugars from the plant in return. Try to recreate the forest floor when growing plants and Mother Nature will step up and fill in any gaps we miss. Wood chip mulch also helps retain soil moisture, key point for summertime. Rambling nonsense from a guy who just loves plants. 

[tim_brissy_13]

Here’s a good article which explains the different uses of different types of mulch:

https://www.ozbreed.com.au/articles/the-good-the-bad-and-the-ugly-of-mulch/
 

As a basic summary, if adding a layer on top of soil, then mulches with only large particles and added as a thick layer appears to be best practice. If the plan is to mix into the soil, then only well composted mulches should be used. 
 

Personally I’ve been using 25mm pieces of pine bark mulch on top of our naturally sandy soil. There is definitely a noticeable difference in soil life after applying, worms everywhere!

[Tyrone]

23 hours ago, Palmfarmer said:

How come some people use woodchips mixed in with their potting mix for planting in pots. I got 2 trachies in a mix of black soil and woodchips and them do well so far. Bananajoe also uses this mix.

The wood chips are aged and composted.

[Tyrone]

Normal natural leaf litter in a forest is a gradual build up of all shapes and sizes of organic matter that definitely build the soil. Mulching machines make everything a uniform size in a very short period of time. In time the pine mulch will build the soil without question, but initially at the soil mulch interface point there will be a nitrogen draw down. Later on not so much and a definite benefit. Throwing a generous amount of pelletised chicken manure on the pine bark and watering it in will set it up to make some nice topsoil in time. But initially fresh uniform pine mulch will cause a dip of available nitrogen at the surface and of course weed suppression. 

[Palmfarmer]

19 hours ago, Swolte said:

I am not sure there's a clear answer for this one but my guess is that it doesn't really matter:
1) These mixes often they use pine bark or a bark that does not break down easily so the idea would be that they improve drainage. I can't see a reason why having large chunks of bark would improve drainage. Its the same myth as folks thinking that adding big rocks would improve drainage. Other than reducing soil, I don't see a large disadvantage either though. 
2) As for those chunks reducing nitrogen and adversely affecting grows:  these potting mixes have no shortage of nitrogen at all, in fact, they are supercharged on it to an unrealistic amount. 

I could be wrong but to test this, scientifically, we would need to grow 100+ palms with and 100+ without the woodchips in a potting medium and compare after 10 years. To my knowledge, no such studies exist. Research isn't cheap or easy and I can't recall experiments like which are ran (they should!).   

Over time the wood realeses nutrients as it decomposes and the nitrogen the wood takes at the beggining might not be enough to make much of an impact is my theory. it is basicly hugelculture on a very small scale. I am not sure if it drains worse or better since the soil is Tierra negra and very heavy to begin with, I would only use this mix with waterloving palms like trachies in my example. I got a few trachies in that mix and i also got some others in a very fast draining mix made with coco, perlite and compost.

Edited June 19, 2021 by Palmfarmer