simple question on hugelkultur materials

So I went searching for a self watering wicking design fro my seedling trays and stumbled upon this world of permies ! Wow what a week it has been especially discovering that the creator of this site is non other than the creator of Java Ranch which I have used on more than one occasion

So I am just a humble home gardener at the moment with aspirations of simplifying to ao country semi-homestead once I can retire. I have most of my garden space planned out however we are installing new beds for flowers and more veggie space and we have a lot of woody mass around and my wife and I would like to try our hand at a couple hugelkultur beds. I have some old pressurized landscape timbers but not old enough to have arsenic in them. Would these be okay to use in the lower layers of the bed ? I also have a lot of evergreen/holly brush trimmings that I can use or burn. I know that cedar is not good but not sure in general about evergreens.

thanks in advance !

Doug

I'd leave the pressure treated timbers out. I mean it sounds like you have plenty of biomass to bury, why would you want to introduce questionable materials? I draw the line at creosoted wood (like RR ties). I'm OK with old RR ties (but some people here aren't), and I throw the green treated lumber I find in the waste barrel to cart off to the landfill.

Evergreens are all right to include. Pines and holly and juniper can be in your mix of wood to bury, and even a little cedar, although if you have to dig it up in 10 years, the cedar might still look the same. The cedar may not have decayed much, but it can still store and release water.

Since you mentioned burning, that's a good way to size reduce some of your biomass -- turn some of it into biochar, and get all the benefits of that carbon in your soil.