green or brown?

I get easily confused about greens or browns in compost. That being said I have never been terribly anal about it. But I have a large amount of partially composted what started off as dried grass clippings and I want to blend with whatever it needs to make better and more complete compost. So would these dried, partly composted grass clippings be considered green, brown, ??? Thanks!

I think it's a brown if it dried out.I could be wrong. As frequently as it is asked online no immediate answer jumped out but I am pretty sure hay is just dried grass clippings and that is pretty universally regarded as browns.

If I am wrong it's now on the internet and hopefully that will draw in someone who can politely point that out and give you a more definite answer.

Of bigger concern if I were composting regular lawn clippings would be adding materials to keep the clippings from turning into a solid anaerobic mass.  Grass clippings tend to mat together. You can get good things with anaerobic processes but it can be very stinky and unpleasant to work with.

Thanks Casie... that's my gut feeling too. They were dead dry when I stowed them with a tarp above and below, but that was 2 seasons ago and some water did infiltrate. The bottom layer is a mat of almost composted grass and not stinky or slimy anymore at least. I'm kinda layering it with wood chips and additional greens.

Hi Gary,
I've been a bit confused by this too. I would have assumed grass clippings: i.e. the short clippings from a lawn for example, would be 'green'. But I've seen in a couple of videos that they are considered 'green' when fresh and 'brown' when dried. This was Helen Attlowe in her PDC presentation about living mulches and cover crops and a youtube video by UK gardener Huw Richards.
If the green/brown is a description of their Carbon: Nitrogen ratio, how does this change just because they are dried out? I would have thought this was just the removal of water, which (H20) has no C or N in, so the ratio dried or fresh should be the same.
Now I understand straw is considered to be Carbon rich so definitely a brown, and hay being somewhat mature and 'stalky' considered somewhere in between. Maybe someone else has an explanation for us, there must be some loss of Nitrogen gasses as the grass decomposes as it dries I suppose.

My understanding of the whole compost thing, the high carbon is in the green component,  chlorophyll,  structure  which is used to absorb red and blue light to convert carbon dioxide into sugars or carbohydrate (photosynthesis).  When the green material is cut down and photosynthesis stops, the chlorophyll breaks down and is lost back to the atmosphere as carbon dioxide again, leaving the structural part of the plants which is lower in carbon but retains the cellular nitrogen in its structure.  The remaining carbon is bound in complex sugars.   It is availability of carbon in green and the nitrogen in the brown as the plant structure breaks down.  Both release energy (food) to bacteria, microbes and fungi.  The food is carbon and nitrites.  Bacteria break down the nitrites to nitrates which are bio-available to plants.  Again, this is how I understand the composting.
Where compost is slimy or smelly, it is apparently breaking down in the absence of oxygen, generating methane.  I am not sure how the ratios work.
Hope this helps

From my readings, I've always understand that green and brown was always just a picture to help beginners since a good compost is more a balance between moisture, temperature and oxygen-carbon-nitrogen.

Paul Fookes wrote:  It is availability of carbon in green and the nitrogen in the brown as the plant structure breaks down.  

Now I'm more confused, I did think it was the other way round.

Aha! Permies and Dr Redhawk to the rescue! We're not the first (and probably won't be the last) to have this debate. I found this from an old thread:

Bryant RedHawk wrote:The first thing to know about Nitrogen both in living plants and the soil is that it is Nitrate or nitrite that we are concerned with.

Free nitrogen (the gas, which is what we are talking about when we say nitrogen) is pulled in by bacterium and converted to nitrates, this is then further processed into nitrites which is the usual form plants can use.

Dormant or dead grasses will contain 3/4 less nitrite than green, living grasses, this is, as has been mentioned, because the plant moved as many nutrients as it could to the roots in preparation for dormancy.

Green, living grasses that are cut and allowed to dry will contain about 1/2 the nitrate and nitrite of the freshly cut, still green and moisturized grass.

For composting you can use grass in any stage, the fresh cut will provide the best conditions for heating up a compost heap since it contains the most nitrite and the most moisture.
Green cut and then dried grass will provide nitrite but will not help in the heating of a heap.
Dead cut (cut dormant or dead grass) will act more like a "Brown" component in a heap.

I think that clarifies it nicely for me at least - thanks Dr RedHawk!

The terms "brown" or "green" are casually used to indicate the ratio of carbon to nitrogen in materials. Green leaves have chlorophyll to give them the color and high level of proteins that gives the low C:N ratio. And the two can be separate. If you sun dry the leaves quickly, they turn brown due to degeneration of chlorophyll pigments, but the crude proteins are preserved in the dehydration process. These brown grass clippings are still "green" in the aspect of low C:N ratio.

Proper storage like keeping them in a dry condition prevents the propagation of microbes and retains the nutrition value. Otherwise, if the clippings are left on the ground and exposed to the elements, nitrogen level will drop due to chemical or biological processes. Carbon level goes down too: the simple carbohydrates are lost faster but the complex ones are more resistant. The leaching of nutrients will benefit the soil underneath (talking about chop and drop). But for using the clippings for composting, then overall the C:N ratio is increasing and now the brown clippings are more "brown" in nature.

What farmers are doing to hay is basically the opposite of composting. They let the cut hay dry out for several days then bale and store them. Dry hay is not easy to spoil and nutritious for animals.

Fresh clippings are preferred for composting not only for higher nitrogen content but also the high moisture level. If you want to use the dry clippings, assuming there are still considerable level of nitrogen left, just make sure the pile is well hydrated.

I hope this brief reply will answer some of the questions.