Experiment

The courgettes are coming away fine. 11 days ago they looked like this.

Since then the weather has turned colder and wetter and we had fairly high winds last week so I put a 2nd tyre on top of some of them, to give more shelter, and on the others I covered the single tyre with a plastic sheet held on with some elastic bungee thingies.

All survived the bad weather well, no ill effects. As yet there is no real difference between the ones with the two tyre high windbreak and the ones under plastic. Both are sheltered from the wind but there is a huge difference in temperature. Under that plastic it is warm and humid.

In theory those in the 'polytyres' should romp ahead, it shall be interesting to see.