Composting Cactus

Answer by JZ: Here are my thoughts. Yes, cactus pads and fruits (tunas) may be added to your composing setup. They would be a source of nitrogen (greens) so you could mix in some dry leaves or paper leftovers, which are browns, with them.  Then decomposition will proceed nicely. You could twist off the fruit and pads with tongs.

You may, with gloved hands, using tongs to hold the pads,  chop them with a hatchet into small pieces about 1” pieces. This not necessary to do, but would speed the decomposition process.  Smaller organics decompose well / quicker.

Important caution – the moist pads and moist fruits will decompose fairly quickly, but the thorns will take longer, so always use a gloved hand when working with this compost blend until it is fully decomposed.

Answer by MR: Before you undertake composting all of them, you might want to offer some to folks who would be interested in either growing or eating them, because they are quite nutritious, both the leaf/stem pads and the fruit. The Master Growers and neighborhood association bulletin boards might be ways to get the word out. I’m not especially tech savvy, but I’m sure some of the other folks could recommend places to post that information.

However, if you just want to recycle them back to the earth from which they have come, the biggest challenge is how to handle them without becoming a pincushion yourself. What I’ve done is to rake them into a pile, rake or scoop the pile onto newspaper–double or triple layers–and either bury them in a shallow hole or trench, still covered with newspaper, or cover the entire pile with newspaper and then add other seasonal cleanup material and good soil, wetting everything as you go. It helps them to break down more quickly if you add some leaf mold to the whole batch. The pads that are still alive when covered with earth will have quite a lot of moisture in them and decompose surprisingly quickly. The needles and glochids, which are the little teeny guys clustered around each bunch of needles (the ones that are so hard to get out–hence the newspaper for protection) are pretty much pure silica, which is one of the fundamental minerals that all growing things need. So they break down very quickly also, and the fungi present in the leaf mold are especially good at decomposing them.

I’ve never tried putting them into a regular batch of hot compost because I like to handle my compost when I’m turning it to see how well things are proceeding, and I don’t want any surprises. And I’ve never used a tumbler, so that’s for someone else to tackle. But the earth will take them all back, free of charge, with just a bit of digging.

If you have a manufactured plastic compost bin you could consider moving it to a sunny location now for the winter months. You may enjoy reading our suggestions for composting in the desert.  See link in our menu.

Hope that this is helpful.   Get back if you have further questions.