I’m needing advice on making garden spheres
The question is on how to build a sphere not how to decorate.
Are you using a medium to hold the concrete in place?
We built reef balls using a similar procedure. (Reef balls are concrete balls dropped on the ocean floor to create artificial reefs for fish to hide)
We would wrap chicken wire around the ball making openings for the fish and pack about 1” thick of mortar with some fine rock called Turkey grit. We mixed until it felt right not runny at all but wet enough to be able to push the mix into the layers of wire.
we would do 1/3 to 1/2 the ball at a time depending on size and let it cure for 2-3 days then do the next section or finish it.
We eventually found that 18” worked the best for our project the larger ones got two heavy and the beach balls did not hold up well. The smaller 12” ones worked but would disappear from the area?
There are all kinds of methods, molds and doing 1/2 shell at a time. we found the wire and mortar mix worked well but using that same method you could build your sphere without the holes once it is completed if the surface is two rough you could give it a finishing coat to make it smooth (we wanted rough surfaces for plant and animal life to attach to).
There are all kinds of examples on line not many do the balls like we did but last time I dove the area. There was a lot of life in that area that was a “desert” before.