Well, you end up with 2 foot long courgettes for a start...
And your fennel grows to towering heights - this lot is as tall as me.
And you start to wonder if there are enough courgette recipes in the world to use up your glut (any ideas anyone? anyone??). See that diddy little one on the right? That's about the size you can buy in the supermarket.
Hmm, talk about fertile.