I use a misting sprayer over top of my compost pile. I leave it on at least a week at a time.

{{gwi:261737}}

No opinion on shape

You probly already know but a loose fitted cover will hold a lot of water in

Oh WOWSER! The misting thing looks perfect. A week? OK -- we may not be as dry as you Texans ...and we're set for a week of rain next week. But when it dries out, I will consider the misting thing. Thanks

Hola Barb,

Especially in the summer, I saturate the organic matter when a pile is built. The "damp like a wrung out sponge" admonition has never worked in our Mediterranean/desert climate for me.

I use 1/2" square hardware cloth wire enclosure that is three foot high and approximately 12 feet in circumference. Once, I lined the inside of the bin with a tarp to keep the moisture inside the pile and covered the top with no adverse anaerobic effects. A root feeder works well to saturate the pile after it is built or add additional moisture when necessary.

The latest quantity of shredded leaves for compost was spread out on the ground before the last substantial rain that we had and then loaded into unlined bins afterward. The top of the piles were left flat instead of being mounded as is usually the case due to the abundance of material so rain would more likely soak into the stack. The outer inch or so is relatively dry, now, but the innards are still moist, though I haven't done the squeeze test to see if a few drops of moisture will come out when a handful is compressed. Didn't worry about it since as you related we are supposed to have some actual drops this coming week.

Terran

Many of us, in areas that get an ample amount of rain build out open compost piles in a dome shape so those piles can shed the excess water while people in areas of the world that do not get much rain would want to build there compost piles with at least a flat top if not one that is slightly dished to catch as much moisture as possible.
Many years ago, when a novice composter, I would pour water on the material (especially the shredded leaves) until water ran off and would periodically flood more water on the pile and I found that that compost always went into anaerobic digestion and it smelled putrid. That is when I discovered that compost does not need a whole lot of water, just a bit.

I use round wire no-turn bins, with a drip line on it so the compost gets watered when the veggies do. Then I planting things in there.

http://www.flickr.com/photos/38617480@N07/3615429064/in/set-72157619569751222/

The piles stay dry on the outside, but you get a nice filling of good compost in the middle. You could try some sort of vinyl slats woven in the wires to minimize water loss, but I've never used them.

The shape of the top is less a factor than their watering it often.

Here is a link that might be useful: Compost bin Phoenix

Water is going to evaporate based (at least in part) on the surface area, so the smallest surface area is also a good rule of thumb. A sphere is the ideal, which of course is hard to achieve, but a cylinder approaches that. Rather than a long windrow or a wide flat pile.

In hot dry weather, a cover such as a plastic tarp will keep the sun and wind off and reduce evaporation. Don't seal it up so well that it doesn't have air.

Barb ; Maybe this will help. I seem to remember the term Mediterranean climate was used with that birds nest compost pile.

Curt~

Curt .... thanks for the reference to the nest-shaped pile. Mediterranean fits San Diego county perfectly.

My two main compost piles are curved top and sides, under Eucalyptus trees. I seldom drag the hose over there, but did water well when constructing them, with occasional buckets of grey water ... and they are gratifyingly warm to the touch. At 73 yrs I don't waste energy on turning, so the piles are loved, but on their own. ....

Since reading about the 'nest-shaped' piles, I have constructed small mini-piles in different part of the yard -- in fallow sections of beds. Dug a pit down to nasty grey DG then layer leaves, horse manure, shredded paper, kitchen scraps -- top it all off with tree mulch from my pathways [nearly composted and full of worms] ... and these small piles are nest shaped in hopes of catching ALL of that WONDERFUL rain we are SUPPOSED to get this winter.

I will take your reminders about evaporation of broader, unprotected areas to heart .... if our winter rain doesn't materialize, I will dome these mini-piles with my plentiful supply of tree mulch. THANKS TO ALL.

We live in a rainy climate and keep the piles covered with tarps, sometimes for weeks on end, to keep them from becoming waterlogged. But I've often wondered about dry-climate composting. Produce (fruit and vegetables) is 80-90% water. If your compost ingredients include a lot of kitchen scraps, which are mostly water, then could you go heavy on kitchen scraps and use less 'browns' to make a wetter pile overall.

Being in the land of 10,000 lakes, my small pile is shaped like a Yurt to shed rain and my big pile (the one with the deer carcass), is a windrow. The Yurt is way cool!

Curt :-)

I'm in a mediterranean climate and I've found the best shape for the arid summers is a four or five foot cube with brick/stone walls on three sides and a removable wood front - it keeps the surface area to a minimum and the exposed surface area is practically nill so the water stays put as much as possible. A concave top is great for conserving water as none ends up escaping down the sides, but it's not so good for making sure that the heap stays moist enough around the edges to compost and I found that only the inner bit would compost like that. I use a virtually flat top in the summer, and cover with an oversized plastic sheet held down by bricks.

In the winter it's different and we get torrential rains and for then I 'dome' the top of the heaps and cover with a canvas sheet so the rain drains down the sides of the heap and the rest of the pile doesn't get waterlogged.