Hi Louise, yes, I had no success with courgettes either. I started them in my little polytunnel, planted them out after the last possible frost date as strong seedling plants. They were mulched, fed and watered as usual using manure from my farm, from animals fed on hay and pasture that I grew, so I know for a fact there have been no pesticides, herbicides or other 'cides for at least ten years. But my crops were very poor. I grew four varieties of courgette, so it’s not that I had a dodgy batch of seed. I simply got very few flowers, neither male nor female and I put it down to the weather. The pumpkins fared a little better but the fruit were smaller than I’d expected.
My mother, who lives only 600m from me, grew patty pan squash in her unheated polytunnel and it was a triffid! This just adds to my suspicions that it comes back to the weather.
And with that being out of our control, we simply have to learn to adapt to suit it. We, as amateur gardeners, are so very lucky in that we have so much choice in our varieties of fruit and veg that we can grow. While we need to embrace the benefits that some F1 varieties offer us in pest and disease resistance, it’s vital we don’t lose heirloom and heritage varieties which give us adaptability to our changing climate.
Don’t lose heart, try again next year and maybe consider growing different varieties. Get together with family and friends who garden and share seeds, all buy a different variety of cauliflower, for example, and everyone still grows a dozen caulis, but maybe only 2 or 3 of each type. Then you can compare to see which variety worked in your garden, without having to fork out for enough seeds to last five years!
You might find some new favourites this way. Good luck, whatever you choose to do.