New Zealand Box in High Dry Climate
February 4, 2021
Hi. About to dive into composting and really finding your information very helpful. I’m up in Las Vegas (NM, not NV), so the heat of the desert won’t be as serious a factor. But the near steady dry winds of April-June will be, and Temps the last few summers have been unusually hot as well. I’m planning on using old pallets to create a New Zealand-style 3-bin system and am wondering if I need to have an air gap at the bottom of each upright pallet to encourage convective air flow? The info refers to minimizing air flow to reduce evaporation, and so I figured I would join the slats of the pallets together except to perhaps leave a small gap (an inch maybe?) between the two slats at what would be the bottom of each upright pallet. Would this be ok or should I not have any gaps at all (or less than an inch)?
Hope that makes sense. Thank you!
Answer by JZ: You have a fine idea in repurposing palettes. They are a fine “skeleton” for a New Zealand Box style bins. You may leave a small gap at the bottom for air intake. My experience that it is not necessary, but if it makes you feel good, do it. You could experiment, in one box leave gap. In the next box leave no gap, then compare moisture management in the 2 bins over several months. For me, no gaps work just fine.
I have been using the NZ box at 3 sites in ABQ for several years. At each of those sites we made the side slats close fitting, with no gaps.
So all of them are very snug – useful in the desert. The front of the bins have sliders so that we can get in, which have a few small spaces (cracks) as they are stacked one on top of the other. These sites are open to public: ABQ Garden Center, Open Space Visitor Center, Bernalillo County Extension Office. See Homemade Bins under Composting Info on our website menu.
An option for you to consider is lining the inside of the palette bin with a appropriate sized tarp. This will help reduce evaporation. The excess top may be used as a cover for the top of your pile.
The way we get airflow in a snug desert bin is not so much with air gaps in the bin but by using coarse bulking material as the pile is built up. Bulking reduces compaction of wet organic material then allows for convective airflow. If you are doing the hot process method then the moist warm air will rise up and aerate the pile – a chimney effect. See the picture of a bulked pile in our webpage about Convective Airflow in the Composting Info section of our website menu. It represents how air passes thru. Bulking is finger size, sticks, twigs, pine cones, corn cobs and stalks. These will not decompose at the same rate as your other organics.. They are sifted out when you harvest your finished compost, then used all over again in your next batch. This harvested bulking is loaded with microorganisms which may serve as a microbial inoculant for your next pile.
The front of the bin may have sliding slats which open so that you can do your work. Importantly – notice that the top of the pile in the attached pic. has a cover drape, which will block moist air from escaping – evaporation. I prefer a non porous drape as in a recycled piece of plastic. Other options would be cardboard, rugs, 4 inches of leaves or straw.
If possible put your bins in shaded are in the summer months. Yes, the summer heat in LV is an evaporation factor.
You may enjoy reading: http://docs.nmcomposters.org/composting-in-the-desert-2018.pdf which describes bulking for both hot and cold process setups.
Let us know if this is helpful and if you have more questions. Compost on !
From original questioner: One more question: sorry to bother.
I noticed that the planks for the NZ style box look pretty sturdy. I was thinking of using 6″ wide cedar fence planks/pickets for the removable fronts, but after seeing those pics and a few other similar styles, I may need something sturdier. Have you or anyone you know had experience using the cedar fence planks?
Answer by JZ: I think that you could cedar fence planks. They get a little brittle after a few years in desert. I coat them with linseed oil once in a while which seems to decrease cracking.
Green pine needles would contain nitrogen. Brown needles would be mostly carbon. As the composting / decomposition process is a neutralizing process, acidity is not a problem. Mixb(dilute) the needles with other organic and all will be fine. Your finished compost will have a pH, about 7.0, neutral.
I volunteer at the Open Space Visitor Center open Tues. – Saturday, 9AM – 5PM, 6500 Coors Blvd. NW, ABQ.. I could meet you there, in the composting zone, whenever.
Keep us informed as your project moves along.
From original questioner: Thank so much. Sure appreciate the quick replies and thorough information. I was using a tumbler I got on sale at Big R, but to no avail. I realize now it was probably too dry inside with all the ventilation holes. And being a church, we go through tons of fresh flowers in a year, and I just can’t stand throwing them all away anymore. The tumbler couldn’t handle that kind of intake, so time to go big!
Maybe I’ll catch you at the Open Space VC in the near future.
Answer by JZ: Sure, You may enjoy reading our pages on tumble bin under Composting Info.
From original questioner: Thanks for that. I evidently did most things wrong, namely leaving it out in the blasting sun. The instructions that came with it said to have it in a sunny spot to heat up the insides, but I realize that what may work in Illinois where it’s manufactured may not work here. Combined with our single digit humidity and ever-present wind, no wonder it failed. Maybe I’ll be it to the shady spot I have in mind for the NZ bins. Looking forward to this adventure in composting! Lol
Answer by JZ: Tumblers can be useful. Yes, put in shade in summer. I use an old tumbler to store my finished sifted compost – useful.
From original questioner: You’ve been a great wealth of info today. I’ve learned a lot and thoroughly enjoyed our correspondence. May I bug you with one more question: with what do I check the moisture level of a compost pile?
Answer by JZ: Sure. Anytime.
This is visual and tactile for me. It is recommended that moisture level at all times be at 50%. I compare this level with the residual moisture in brewed coffee grounds, or a squeezed out tea bag or a wrung out sponge. Look at brewed coffee grounds after they’ve drained for five minutes, see how they glisten with moisture, stick a finger in so that you feel this moisture level. When you look in your bin the ingredients should “look” and feel moist. With a gloved hand grab some of the organics in the bin. They will be sticky moist and clump together, but should drip very little when squeezed.
There may be a tool / product for checking moisture (?). I just use visual inspection and a gloved hand.