Maybe check out the hypertufa forum to get some ideas. You could use styrofoam to make molds and make them what ever size you want. I would make them in like two halves that would fit together around the post. You could make them a deep as you need them. Depending how you positioned them you could grow sun loving on one side and shade loving on the other. Use your imagination. Pam

Your deck was designed to support X amount of live load & Y amount of dead load. Typical deck live loads are 40 to 60 pounds per sq ft (if you are in a snow area that range might be more) & typical deck dead loads are in the 10 to 20 psf. With the Pergola being constructed out of IPE the weight of your lumber will be at least a couple hundred pounds so you will have greatly exceeded the dead load rating of this deck, given it is anywhere close to typical construction. So, bottom line, as John stated you need a continuous connection from this IPE post down to the foundation.

Dap makes a painters puddy that comes in powder form, you mix it with water then apply in holes. You can add you stain into the puddy when mixing it up so it will be closer to matching the color of the redwood. Al

Thanks. I was in a Mutual Materials today and they only carry one style in 20" or 22" and I'm still not very pleased with it at all. I've seen nicer stuff out and about (not at retailers but at shopping centers/etc.) that has a sheen to it, looks much nicer than the stuff I'm seeing from Mutual Materials and Eldorado Stone and with the sheen I think it would keep its finish much better than the raw concrete stuff which doesn't look good right out of the gate, much of what I see is already discolored, chipped, etc. Not a good start.