Here are some of the fake stone planters I have made. My plans were to make more troughs and plant them with alpine plants from the different countries we have visited, but the plans have been altered slightly. Some of the larger pots I had made have been given away and I don't have photos of them.
The pots are made using portland cement and lightweight aggregates. Usually some combination of perlite, vermiculite, polystyrene, some peatmoss and sometimes sand. Usually about 1 part cement to 3 parts aggregate. I try to see how light I can get the planter to be without it being too weak. The less you pack the mixture into the mold the lighter it will be, but it would also be weaker. I had one trough that would have been just perfect, light and strong, but I disturbed it too soon and it was ruined. One of the pots I made using packing peanuts chopped into quite large pieces. After it had cured, I poured gasoline on it to dissolve the polystyrene, this left large voids. The plant in this pot tends to dry out quick, but the pot does look interesting.
This one has peatmoss in the mix and has wooly thyme planted in it. The mix also had green cement pigment added.
This pot has had brick red pigment added, there is a lot of vermiculite in the mix and there is also sand, I have tried to get coarser vermiculite, but the fine grade is all I have purchased so far. Shundler in NJ sells all kinds, but I haven't contacted them yet.
The 2 plants in this trough are Erinus Alpinus "Fairy Foxglove" and Alpine Campion. The trough looks very concretey, I tried smearing moss into the sides, but it has been too dry for them to take hold. I was going to say root, but they don't really have roots.
This trough has hardware cloth as a core, so the sides don't have to be as thick and has peatmoss included with the vermiculite. It contains Alpine Campion, rock cress, edelweiss and a gnome in a shallow grave.
I have used 12 AWG copper wire to keep this trough from falling apart. I tried to remove the inner form too quick and ruined the structural integrity of the trough. The campenula that calls this trough home has smaller leaves and flowers than the mother plant which is in the ground. This trough is really light, just perlite, vermiculite and portland cement, I like the patina it has acquired.
Green cement pigment, perlite and vermiculite as aggregate.
I tried lump charcoal as an aggregate in this small trough. While the charcoal is really light, I should have used more because it is mainly cement and quite heavy.
This is one of my favorites. No peatmoss, just perlite and vermiculite.
Another made over a hardware cloth form. I included sand in this one.
Another with green pigment, the Creeping Jenny plant is considered to be an invasive weed by some.
Creeping phlox, yellow cement pigment, vermiculite and pearlite.
Two bowl planters, one with black sand added (right), one I tried to polish (left), neither with peatmoss.