My husband and I moved from Western Oregon to the Morongo Basin in inland CA, a hyper-arid desert region (zone 9a, 4- 6 inches of rain per year). A big problem I've encountered in this hyper-arid desert region is how to compost. In Oregon, as the joke goes, "compost happens". It never took any effort. And it attracted the most lovely creatures, like rubber boas who would live in the piles and take care of any rodents. BSFs, pills bugs, centipedes, millipedes, tons of worms - an Oregon compost pile is a fantastic ecosystem and wonderful source of food for birds, too.
But here in this desert, compost doesn't "just happen", we discovered! For one thing, there are no worms in the soil here - it's a decomposing granite sand. We've dug good sized hugelculture pits - not a bug in sight. I don't think it's a spray issue, the ground is just incredibly dry.
After building a bunch of sunken hugel beds, we first tried composting in an old planter the same basic way we would in Oregon. This looked fine at first, and it smelled perfectly fine, but we soon discovered it attracted rats. This may sound funny, but where we were in Oregon rats weren't a big issue (tons of natural predators), so I wasn't accustomed to that problem.
We dumped it out to put the compostables into another hugel pit and deal with the rat issue, and discovered another issue - the base had become a huge nest of cockroaches. Oh my. Again, I'm cockroach naive, as the PNW is not big cockroach territory. Too bad I don't have a picture of that scene...hundreds of cockroaches scurrying all across the ground, trying to hide at our shoes, find anywhere dark to return to. Quite a sight.
We have no birds to feed the cockroaches to and they were getting them in our house, so we've stopped attempting to compost above ground now. Everyday we bury the kitchen waste in the existing garden beds. The existing hugels seem to working fine. They have a bunch of fungi filaments growing through them. It seems fungi is the dominant composting mechanism here. I don't like repeatedly invading the garden beds, but we haven't figured out any other way to avoid the rats and cockroaches.
Does anyone have any suggestions for composting in this sort of desert region? Composting that won't attract cockroaches and make our neighbors very unhappy? :-)
Be joyful, though you have considered all the facts. ~Wendell Berry
Hi Kim. I tended compost in many configurations in Tucson for about thirty years and learned a lot in that time. I know exactly what you're up against and you might have settled on a good method for now: excavate and bury in batches, and keep moving around.
Some observations I made over the years of drylands decomposition:
Air circulation is good, but it's easy to have too much and lose all your pile's moisture out the sides and top. Cover and restrict how much air moves around the pile.
Direct sun will also dessicate your compost. Shady spots are best if you've got them.
You're more likely to be N deficient than folks in humid climes, so kitchen scraps, manure, and any green matter that hasn't dried out yet are always good to have.
Cockroaches love compost heaps. They're doing some of the important work in there but I can relate if you're not keen on having them around. I kept my pile in the chicken run for many years and that was a win-win. Every time I turned it was a fiesta for the birds.
Sometimes you may get other predators to take up residence and keep the roach population down...in my case we had geckos move in and then I was reluctant to turn the pile because I *didn't* want the chooks to eat them. Too damn cute, those geckos.
Pit composting is awesome in the desert, especially if you don't have drainage issues (otherwise a rainstorm can turn your pit into a cesspool or scatter it about the property).
Zai pits, waffle beds or hugel pits can be done one at a time and serve as receptacles for all your scraps and compostables. When one pit is "done" you plant it and start the next one.
Some folks have really good bokashi systems that work well for them in arid environments.
Thank you Phil! That was a really detailed and helpful response!
We definitely learned how keeping moist was important. "Check" on that one.
We used urine to keep it moist, and I was amazed how it seemed like we could never put too much urine on it. In a place like Oregon, you'll know pretty quick if you've added too much urine to compost. Here in the desert it just soaked it up. I was amazed by the almost total lack of smell to this desert compost pile. Interestingly, though , we also learned that urine on garden plants in the garden could easily be overdone and kill them. A wacky difference.
I figured the cockroaches were useful. When we get further from neighbors, and have birds again, I won't worry about it. It'll be a bonus.
Here in this neighborhood, people are really spray-happy and the last thing I wanted was for our neighbors to start spraying for a roach infestation!
Geckos! Geckos! Geckos! Say no more.
That's a really good point about pit composting, the risk of it filling and floating off. I hadn't thought about that, because it doesn't rain near enough here for that, unless you stuck your pit directly in a wash. But we will be moving relatively soon, to a moister desert, and that is valuable information.
Good to hear about bokashi. Loved our bokashi in Oregon. Looking forward to starting again.
Thanks so much. If anyone else has more or different feedback, please do add to this thread. It may seem so elementary an issue, but this has been quite a learning experience for us!
Be joyful, though you have considered all the facts. ~Wendell Berry
The only thing I can add to Phil's great suggestions is that bins in the shade work great in desert situations.
The bins hold the moisture in better and it is easier to control evaporation losses along with air flow.
Adding spent coffee grounds will up the nitrogen levels and should you want, you can also make mineral additions.
Molasses is another addition you can make to up the bacteria numbers, this will also increase the numbers of other microorganisms you want in your compost and soil.
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yah i agree keep in shade and in closed with palets or something and try not to let it dry out then it becomes really hard to get moist again. a cross with a spiral of drip line tyed on works great. the cochraches and rats will leave when it gets wetter i get this problem when i forget to water.
A bit pricey but our solution was to get one of those raised, double barreled compost rollers. Metal. Solved the rat problem. Dries out a bit quickly so we just add kitchen waste water to it very now and then.