Stone sinks are difficult to find, and they are expensive to buy when you track one down, but the old porcelain models are more readily available at not such extortionate prices. It is then quite easy to convert one into a good replica of a stone sink, by cleaning it, coating it with a contact bonding adhesive, and then applying a roughened layer of cement, sand, and peat, mixed together with water. The mixture should only take a few hours to dry thoroughly.
Once filled with soil and rocks, the sink will be immensely heavy, so place it in its final home while it is still empty. Even empty, it will be very heavy.
If you intend to plant the sink with alpines, put it in a dry, sunny position and raise it on bricks or some pieces of stone, so the plug hole is well clear of the ground. As the roots of alpines dislike the wet, cover the bottom of the sink with a very thick layer of drainage crocks or pebbles, and fill it using a potting mixture which has a high gravel content. Coat the outside of the sink with live yoghurt and it should soon weather to resemble an old stone sink.
For making a sink garden you’ll need: a ceramic sink, a contact bonding adhesive, an application comb; cement, sand and peat (proportions 8:2:1); trowel, old paintbrush, crocks, potting mixture of medium nutritional value, with fine gravel (proportions 4:1); tufa or porous rock and large screwdriver.
1. Thoroughly clean the outside and inside of the sink garden so that it is free of dirt and grease. Apply an even layer of contact adhesive to the outside surface and the top 5cm (2in) of the inside surface.
2. When the glue is tacky, apply a 1cm thick layer of cement mixed with sand and peat. Smooth on firmly with a trowel and roughen with a paintbrush.
3. Place the sink garden in its final position, and raise it off the ground with bricks or stones so that it can drain freely. Cover the base with a thick layer of crocks for good drainage. Fill the sink with potting mixture and fine gravel.
4. Arrange tufa over about a quarter of the surface area of the soil, leaving sufficient room for all the plants. Using an old screwdriver, chisel out holes in the rocks for stonecrops and houseleeks.