A cheaper tomato trellis
The wire cages I bought two years ago bend under the weight of a good crop and are impossible to store. This year I tried the old approach instead: three bamboo canes tied at the top into a tripod, with twine run between them in a spiral every twenty centimetres.
Notes
Tie the twine to the canes with a clove hitch so it does not slide. Prune side shoots weekly. The plants lean on the twine instead of being strapped in, and air moves through the whole thing, which matters in a damp summer.
The canes cost almost nothing and will last two or three seasons. I will keep the cages for the beans.