I maintain numerous RO bone compositions. One of the real issues when planting root over bone is that bone breaks down, this requires ongoing cleaning and periodic applications of epoxy. I have found untreated bones or skulls start really degrading after a decade. For me, I have found that pretreating it initially is important. I dry out the bone and make sure it's free of organics, sometimes I microwave, sometimes I bleach some, then, once bone dry( haha) I soak it with penetrating epoxy, topping with thicker and thicker epoxy, and dab it enough to keep it from being glossy. I use professional type epoxy (West Systems) make your own penetrating epoxy by thinning this with acetone enough to get it to soak in then let it set-up good and do it again. Then let it cure all the way so volatiles from the epoxy doesn't bother the plant. This is the easy part. Ongoing maintenance is trickier, I wait until a droughty time when the bone is really dry, protect the soil with aluminum foil and them clean the bone of algae stains if you get them--watered mixes of peroxide and or bleach used judiciously work well then let it dry in the sun, now you have to be very careful and have an arsenal of swabs and squirters and dabbers ready, make up your penetrating epoxy mix and go over the piece like before--I have used acrylic wood hardener (PC wood hardener) for this, which is less toxic and easier but the real epoxy clearly last much longer. I go over the pieces every 5-8 years really paying attention to anything touching the soil( which I excavate and dry out well before treating). Hope that helps--Oh and don't slap a plant on the skull unplanned and without plenty of assembly time. You really have to work to a higher standard when doing avant-garde scrutinizing position and attitude. Art is art, be awesome. Good luck.
View attachment 275084