If it's steaming, I'd say that's a sign that there's a good mix of manure and sawdust. Sawdust by itself can be good for gardens if it's used as a mulch, but can tie up nitrogen if it is worked into the soil without a nitrogen source.

You can add all the fruit to the compost. It would decompose faster if you chopped it up, but it will decompose if it starts whole, also.

If it's turned black and steaming, it sounds like it already has a pretty good ratio of manure to sawdust. Adding coffee grounds and scraps from the market will help speed things up. I also save pee and add it to my sawdust and donkey dropping piles, which helps. Racehorses tend to be fed a much higher protein diet than they really need, which means that any surplus will find it's way into the bedding which is a good thing from your point of you. I usually cut citrus in half when there are too many to feed to the donkey, but I don't think it's strictly necessary.

Since sawdust comes from dead wood (there is only a small living area in tree trunks called the cambium layer) the only real source of nutrients would be from the manure, and although that might be pretty good that now composted manure may cause soil nutrient deficiencies. It is always better, when composting, to provide a wide variety of material and the wider the variety the better the level of nutrients. Adding the fruit waste, and yes citrus can be composted, is a good idea because that will add another source of nutrients. Some people have noticed that if citrus waste is added to a worm compost bin bad things happen, but I've not seen that in my compost piles although I've not added tons of citrus waste at one time.

Hi Wade

Was there any appreciable heat from the HM pile? It is possible to get 'steam' without a lot of heat so the steam itself isn't necessarily a great indicator that there was a lot of heat. Now, copious amounts of billowing steam would be different than wispy steam and would probably indicate substantial heat in the pile. High heat would indicate a decent C:N mix "in the range" while just warm would be an indicator of the C:N being on the higher side.

Adding a "lot" of UCGs would also be a great N source so I'm guessing you have a decent mix in your pile. Egg shells take a loooonnnngggg time to break down and I often see bits of shell in the 2 year old 'post.

Soft fruits seem to decompose pretty quickly but thicker skinned fruits (oranges, limes etc) seem to be able to resist the microbes for a longer time. I've seen whole oranges come out of the tumbler after 3 weeks of high heat looking like a green tennis ball but the inside is still recognizable as orange pulp. I try to at least break the skin, seems to speed up the decomposition quite a bit.

Lloyd

You gotta be careful with blanket statements, esp when it comes to gardening or composting :)

Any time someone "discovers" a garden "truth" or "rule", someone else is sure to find the opposite just as true.

"I have heard that too much sawdust is not good for gardens"

As stated above, in large quantities fresh sawdust can tie up nitrogen in the soil. Of course if you are turning grass clippings etc in at the same time, the nitrogen hit is not so great - and not so bad. It's relative! As for sawdust generally having no "nutrition" value for your soil, sorry, that is simply not the case. Sawdust all by itself (along with an army of microbes and worms) transformed a patch of clay soil magnificently for me. Took three seasons, and 2 pickup truck loads spread almost 6 inches thick. Years later there is no sawdust to be found, and the soil is lighter.

Some mighty fertile ground can be developed using nothing but sawdust (material-wise). Having manure in there is just more goodies for the soil web. You don't gotta have the fruit or coffee grounds, but they aren't going to hurt much (another blanket statement) but in concentration, grounds can make things acidic for you.

Sounds like a terrific opportunity for your garden to me!