Hi Colleen

I'm just running out the door to go coach youth bowling but I will give you this link. It was one of the first documents I read where I could grasp the concept.

Lloyd

Here is a link that might be useful: The Importance of Compost Maturity

Thanks, Lloyd, for that link. Now I get it - simplistically -
if it's too hot it will consume the
nitrogen out of the soil thus
possibly killing the plants. Colleen

It's not just the possibility of nitrogen deficiency. Still active compost may use up a lot of the oxygen in the soil basically "suffocating" the plants. It may also alter the Ph of the soil or release phytotoxic compounds either of which may be detrimental to plants.

Now there are circumstances where unfinished compost may be used and the advantage to that is not having to wait for complete maturity. I have incorporated immature compost in a vegetable garden (Aunts') in the fall. The idea being that the 4-8 weeks in the fall and 3-5 weeks in the spring is sufficient for the material to 'cure' in the soil. But I don't let my compost go out to the general public unless I am completely satisfied that it is very mature. That's just the way I do it.

Lloyd

Although Colleen hasn't asked my opinion, I'll offer this from personal experience - unfinished compost is hard on transplants and prevents germination of seeds. I have mistakenly used unfinished compost in my garden beds.

My compost had started out as a hot compost, but when it cooled off and I turned it, I piled it too deep and the compost in the bottom of the pile became packed and lacked air. It composted anaerobically and turned into a nice black mud, but it was probably full of the phytotoxic compounds that Lloyd refers to; oxyalic acid, butyric acid, and other related acids.

I had applied this black mud, this anaerobically created compost, to my garden beds assuming that it would be ok. If I had screened this anaerobic compost and let it dry out and sit, it surely would have finished within weeks. Instead it had to finish in my garden soil and until it did, my plants struggled. (But, once that compost finished in the garden soil, the plants bolted).

I learned two or three lessons; 1. don't let the compost get packed unless you are deliberately making unfinished compost, 2. if it does get packed, screen it and let it dry so it can finish, 3. unfinished compost is hard on garden plants.

Why would a person deliberately make unfinished compost? The acids in unfinished compost prevents seeds from sprouting and suppresses root growth. So it could be used on a fallow garden bed in late summer/early fall, or between rows of established plants, to help suppress weeds.

I'm going to try using unfinished compost this year in places like my strawberry bed. Once the strawberries are picked, I'll mulch the bed with fresh, unfinished, screened compost, covered by straw. The compost will suppress weed growth and by the next spring, it will be finished and ready for the new crop.

First off, thank you both for replying - all input is welcome and I should not have put anyone
on the spot asking for advice. Both replies were very informative and Lloyd's link was useful and appreciated.

I'm amazed at the multiple uses of compost in its various stages. I like the idea of putting it between the rows
to suppress weeds - if this were done in a vegetable garden would the rows have to be any further
apart in order for the unfinished compost in between to not be harmful to the plants?

I think I may be in trouble because just last weekend I shoveled away the snow in my vegetable garden and
buried a small bucket of fruit peels, apple cores, onion skins, egg shells and UCG's in a shallow 2 foot x 1/2
foot trench thinking that by planting time it would be finished compost - luckily I was just experimenting
and only did the one bucket (it really had nothing to do with how tired my arms got from
moving the heavy snow and digging up frozen dirt although I have to say that it was much easier dumping
that second bucket on the pile and not burying it).

I wanted to bury it because I recently read (here?) of someone posthole digging multiple areas in the
garden in the fall and filling these holes throughout the winter with compostables. I was hoping, since I did it so late,
that the worms would help to finish it off but now I'm worried about all the harm to plants mentioned by
Lloyd and Idaho gardener. It was just a small bucket so, even though it didn't have the fall season, hopefully it will not
be a problem. I guess I'll find out in the
late spring when it's dry enough to work the dirt. Colleen

I've followed this board for 2 years and this is perhaps the most valuable info. I've received. I had NO IDEA about adding unfinished compost to beds. That answers my problem to many failed flower plantings!

The bed that I had been adding unfinished compost to last year is fabulous this year. I was simply playing in the dirt (and w/my cat) in that area today, getting the soil loosened up for spring planting and was amazed at how good the soil looked. Now I know why my veggies didn't do well, but the soil looks great now.

Thanks for the great question and the excellent replies!

I'm not sure we can equate partially finished compost with raw veggies, UCGs and eggshells.

Somehow I think that if the raw veggies are buried, it's not the same as getting them partially composted and then using that compost. I don't have anything like a link or study but my gut tells me that it's the active composting that takes place in a pile that creates those temporary undesirable traits. Burying the material in smaller quantities would probably be okay and I think you will be fine.

Having said that, what the heck do I know!! :-)

Lloyd

I haven't been on for a few days, so I apologize for ignoring your question. But I see that it has been answered quite well (better than if I had tried to answer).

Thanks to all for your very interesting and valuable input.
Bluelake - I had no idea, either, but it certainly makes sense.
BTW, happy belated birthday (I checked your page
because I was curious where you lived in zone 8 and was jealous
that you're preparing for spring planting when, even though today is supposed to be about
50 degrees, we still have about 4-5 inches of snow left on the ground). Colleen

There is trench composting and sheet composting, where one is literally composting right in the garden.

sugarmaple, another element of all of this that hasn't been mentioned yet in this thread: the effects of compost on soil structure. Finished/cured compost helps soil structure in at least two ways - introducing organic material, and feeding all of the micro and macro beasties in the soil food web. But unfinished compost, it seems to me, does a bit more of both. In the process of decomposing organic material, both little and big beasties produce chemicals and excretions that tend to bind little bits of soil together in amalgams, changing the texture of the soil.

I garden in clay soil; clay particles can pack together too close so that it is hard for water or air to penetrate. But if clay forms into little irregularly shaped bits, leaving gaps in between, its structure is much better, letting air, water, and roots penetrate. Some of the benefits of having organic material in soil is that the beasties eating the organic material tend to make the soil have a better structure.

I imagine this outcome might matter more in clay than sand; my mom gardens in sand, and water/air penetration is never a problem in her garden. Water holding is, of course, and organic material helps for that quite a lot, but I don't know anything about the benefits of rotting-in-place (in the soil rather than in the compost pile) for sandy gardens.

So - long answer short, one benefit to not-yet-cured compost is better soil structure. Even so, as others have said above, the plants may not do quite as well until decomposition in their immediate vicinity has settled down some!

- lcpw

joepyeweed - I haven't yet gone out to rototill my garden (I know, I wanted it done last week but too busy with work, and for the past month's weekends, two wedding showers, mother's day, and this weekend, a wedding and our townships cleanup day) but I can't wait to see what happened to that bucket of compost I added in January. If it looks good, I may end up burying my compost in the garden during the winter. I'll have to look up trench and sheet composting - sounds interesting.
lcpw - I garden in clay, too. Add to that, our property is on a slope and I'm afraid that each time it rains hard a small percentage of soil nutrients flow from my garden. This year I'm planning on putting some untreated wood or boards on the uphill side of the garden in the hopes that I won't be adding any more water for the runoff. I don't really want to level the area because it would be such a huge job (and I don't think my husband would approve of such a task - lucky for me!) So, by trial and error, I hope to someday find a way to garden well in clay.
I'll have to come back after I rototill and let you know what happened with January's bucket of compost - nutrients for my soil or ... who knows?
Colleen