About greens and browns

[mellotango]

Hi,

I'm learning about composting, and am currently grasping the concept of C:N ratio. From gardening tips, it seems that browns (sawdust, dried leaves, wood chips I.e.material that is high in carbon) and greens (fresh grass clippings, green leaves/vegetables, I.e. material high in nitrogen) mixed together makes a good compost pile.

However, I have a specific question to ask about leaves. For brown leaves, I assume that it is no longer high in nitrogen value, as it has been washed or leached away by rain or other elements over time.

But what if I took some fresh green leaves, oven dry it, which immediately turns it brown in color. Will the nitrogen still be locked up within the dried brown leaves? In this case, is it considered a brown or a green still?

[rainbowgardener]

Leaves are a tree product. As such they are pretty much a "brown," even in their greenest (color) state.

Here's a table of C/N ratios:

https://compost.css.cornell.edu/OnFarmHandbook/apa.taba1.html

Note that wood chips, very brown, have a C:N ratio of 560

Chicken manure, very "green" (very hot, nitrogen rich) has a C:N ratio of 6

Leaves (by which I take it they mean freshly trimmed/raked) C:N 54, comparable to oat straw, paper mill sludge, shrub trimmings.

So I consider it a brown to start with. I don't know why you would waste energy drying your leaves. I do use fall leaves as my main brown. Collect bags of them when people put them out at the curb, and use them all season.

If you are looking for other browns, there's a sticky at the top of the Compost Forum (might have been a better place for this topic) on greens/browns, which is where I found the above link. It has lists of browns, including shredded paper, brown paper grocery bags, used paper napkins/towels,

[mellotango]

Leaves are a tree product. As such they are pretty much a "brown," even in their greenest (color) state.

Here's a table of C/N ratios:

https://compost.css.cornell.edu/OnFarmHandbook/apa.taba1.html
,

Thanks for your informative reply. The reason I'm looking to dry fresh leaves is because I'm working on a project to pelletize them into mulch and the process involves drying the material to a certain moisture level. And finding out that leaves have a C:N ratio of above 50 is important, as this may imply that we have to add some external sources of nitrogen during the pelleting process to lower the c:n ratio. This will help the mulch avoid taking too much nitrogen away from the soil, as a result of being too high in carbon ratio.

Btw, I can obtain plenty of palm fronds around my area. Does anyone know the C:N ratio of palm fronds?

[toxcrusadr]

That explanation of your project brings up another point. Mulches, which are in contact with only the surface of the soil, are not considered to be nitrogen-robbing even if they are very high carbon (like wood chips). Only if they're tilled into the soil do they cause problems. Without going into the gory details, suffice it to say that you don't really have to worry about pelletized leaves robbing nitrogen.

In fact, at 50:1 leaves will break down fairly rapidly - which is not a bad thing. I use shredded yard waste mulch from the city, and it disappears every year into the soil, which only improves my beds. (Some gardeners till shredded leaves into their gardens in fall to break down over winter. As a mild brown they have time to decompose and correct - but I digress).

OTOH some people don't want to mulch any more than they absolutely have to, so they use the highest carbon material they can find (wood chips) so it lasts longer. Even this does not rob nitrogen from the soil below.

Curious, what got you into pelletizing leaves as a mulch? Very interesting project - tell us more.

[Halfway]

I'm dreaming of covering all the raised beds in..................TUBES! I wonder if I could pelletize tubes?

Sorry OP, just heaving a bag of tubes to the compost heap!

[toxcrusadr]

I hope those weren't vacuum tubes.

[mellotango]

Tox, thx for pointing out the facts about nitrogen robbing. Also, in response to your question, a few reasons:

1) A recent interest in recycling prompted me to purchase a shredder and pellet mill. Put simply, my new novelty toys...

2) I have access to plenty of leaves in the form of green waste or pruned fronds from nearby plantations

Mulch in the form of pellets might have some benefits. They are dense and heavy to start with, which means they don't get blown around on a windy day. And they are easier to spread by hand, maybe great for potted plants. You'll probably only need to add only a thin layer, since watering the pellets can cause it to expand about few times its size. And since they are about 8-10% moisture, they can be stored for a long time.

That's the theory anyway. If anybody can forsee any problems, or non-viability of this project, pls feel free to point them out. It'll def help during the course of my experimentation.

p.s. I might also try to add nitrogen rich plant biomass into the mixture to get the c:n ratio to 30:1 so that pellet mulch breaks down faster into compost. Any suggestions?

[toxcrusadr]

I wanna see a picture of your pellet mill!

[Dixana]

I'm also curious to see it and hear how this works out. Could be a very interesting project. The place wezore moving is up on a hill and it getts REALLY windy out there. I'm wondering how much of my mulch is going to blow all over instead of staying in the garden.

[Tilde]

Bumping to learn about the pellet experiment.

I did some researcn on palm fronds - seems to be two schools of thought:

1. run them through a chipper - they are tough and hard to break down.

2. They are bad and stay away (the tips contain a poison one site clamed).

I have them too, not a lot, but a bit. I've dried them and piled them at my relative's house; they take a loooong time to break down. I might just hang on to mine and use them as weed blocking material.

https://edis.ifas.ufl.edu/ep323

https://www.madehow.com/Volume-5/Compost.html

This seems to indicate that date palms have a ratio of between 53-63 to 1 c/n ratio:

https://www.academicjournals.org/AJB/PDF/pdf2011/6Jun/Ghehsareh%20et%20al.pdf

your mileage may vary.