I have been impressed with the amount of cucumbers a couple of Air-Pot containers can produce. Enough to eat loads in salads, make endless gazpacho soup and also pickle in vinegar.
Previously I have bought the very expensive F1 hybrid seeds and put one plant in a 20 litre  Air-Pot. Sometimes several flushes of beautiful cucumbers result, but if the one or two precious plants succumb to some ailment all is lost.

This year I sowed lots of cheap Polish ridge type cucumber seed and planted three in a pot. They are in the greenhouse scrambling up a trellis and seem more robust than the thin skinned all-female English types. Admittedly they are small (about 15cm) and are a bit prickly but the yield is huge and staggered, and the prickles rub off easily. Some plants are probably not as productive as others but that does not matter when there are several plants in a pot. So lots in a pot will be my method in the future.

The yield has been good from an Air-Pot potato tower that has been on the patio after an early start in the greenhouse. Rather than open it early and risk a lot of the tubers still being very small it has been left until well into July. Three Casablanca tubers planted in a pot have produced 3.5 kg which is more than I get per plant when grown in the ground. Three plants at the plot would generally produce 3 kg & take up an area about 1 metre square, whereas the potato tower has only a 42cm diameter. So with four potato towers fitting into one square metre small spaces can be very productive. The key to success has been plenty of water.