Thursday, August 18, 2011

Notes from the garden - soil

I think the biggest reason my vegetable garden isn't more productive is the soil. I've read that good soil should have about 5% organic matter and mine's nowhere near that (many western soils only have about 1%). The easiest thing to do is dig in bags of organic soil ammendments, but that's also probably the most expensive way. Nonetheless, I added 8 large bags this Spring (and about twice that last year) and some places are a little better, but it hasn't made enough of a difference.

Last fall and in between plantings I dug in as many leaves and kitchen scraps (plant matter only, of course) as I could. They seem to break down pretty fast but I'm still not seeing much visible improvement so I'll keep doing that each fall. I never have to mow the lawn (one of the perks of your wife running a landscaping business) but I'd like to get my old mower running again so I can chop the leaves up first. That way they should break down faster.

I'm also trying composting again. I tried a compost pile in Utah, but I don't want an unsightly pile in the yard.  Besides, it took forever, and I wanted to see if I could speed it up. I've read about compost tumblers that promise perfect compost in 2 weeks but they cost $300 to $400 - and if I were going to spend that much I might as well spend it on bags of soil ammendment. (Also, I'm a little suspicious of the claims those companies make.) So I found a basic plan online for making one, and with a trash can, some scrap wood and pvc pipe, and a few hours one Saturday afternoon I made my own.

The stand holds the trash can up so I can turn it around once a day, mixing everything inside. The pvc pipes, which run through at different angles, break everything up and have slits cut in them to allow oxygen to mix in when it tumbles. Unfortunately, I used pretty large pipes which seems to dry it out faster, so I've covered some of the ends. The lid stays on even when it's upside down. And it's on the south side of the house where it gets plenty of sunshine to help heat it up. It's not as pretty as a commercial one, but the price was right.

It all breaks down to a lot less volume than when it went in.  And I've decided I didn't need all the pipes - just turning it over mixes everything just fine.

The only problem is that it doesn't seem to be working much faster than an ordinary compost pile. I think part of the problem is that I didn't chop up the leaves that went into it initially. I also think the carbon/nitrogen mix wasn't ideal, so adding nitrogen fertilizer has helped. Also, since it's a pretty small volume of material it might not be heating up as much as it should. But kitchen scraps that get added in quickly biodegrade and disappear, and I've had no problems with bad smells. I'll keep working at it to figure out how to make it decompose everything quicker. It probably won't add a lot of organic matter to my garden, but it's something. And besides, it's recycling things that would otherwise just go in the trash.

I guess this is the downside of using a plastic trash can.  I leaned on it a bit when the plastic was especially warm and soft.  I'll have to figure out a way to fix it.


  1. Did you try adding worms to it? To speed up the process. After all, it needs worms to produce the dirt. Maybe increase the number of worms will help.

  2. (I don't know why but it won't let me comment as my self from work, so I'm commenting as "anonymous")
    Hi C. Merced - do I recognize you from Vine? If so, thanks for stopping by.

    Yes, there are *some* earthworms in the soil, and when I've found them elsewhere I've carried them to the vegetable garden (which is my focus for now). When I soak the tomatoes I see a few come to the surface (but that's one of the areas that *has* improved). But I don't think I've got enough organic matter in the soil to sustain a decent population of worms, which is why I'm trying to add everything I can.

    I can't add them to the composter because the whole idea of composting is to heat it up enough for the aerobic bacteria to break it down quickly. Ideally, it should get hot enough to kill any weed seeds and other pathogens, and that would kill worms, too. I don't know if mine is generating that kind of heat, though, and I should probably check. But now that I think of it, maybe it would be worthwhile to try adding some worms to the composter during the winter months when it probably won't heat up as much. They might really thrive and take over when it's not warm enough for the bacteria.

  3. Yep! Vine!

    You can also try adding different types of things. The pH may not be well balanced. Try adding coffee beans, banana peels and yes, leaves, which is what you have been doing. Paper also helps cause it becomes mushy quickly.

    You can also buy worms at the pet store. :D

  4. Well thanks for stopping by! Hopefully your Vine "targeting" has been a LOT better than mine lately. (I think one of the forum comments about a monkey doing the targeting was pretty close - but I don't mean to sound ungrateful, either!)

    The pH might have been part of the problem initially. We have very alkaline soils here (as opposed to the acid soils I hear you have in the East) and I put a bunch of ashes from the fireplace into the composter when I first started it. I later read that ashes are very alkaline and not the best thing to add to our soils.

    I think another problem was too much carbon and not enough nitrogen. Grass clippings would be a great addition but I'm not sure what the gardeners do with them. I'll have to ask them to save some for me. In the meantime I bought a bag of cheap ammonium sulfate fertilizer and things started to decompose much quicker after adding some of that.

    The biggest problem was probably that the leaves weren't chopped small enough, so they took longer to break down. When I'm able to dig leaves directly into the soil they disappear pretty quick. When I make sure the kitchen scraps are small (banana peels, too) it all seems to disappear pretty quickly.