Finale
fennel bulb in the UK

Fennel likes to go straight into the ground, to be honest, so sow outdoors from April right through to July. You want to make a drill about 1.5 cm deep and sow your seeds thinly. Space them out about 15 cm apart once they're up and growing, with 30 cm between rows. Keeping them moist is key from the start, it stops them thinking about bolting too early. You can sow a small batch every few weeks for a continuous harvest, like I say, right up until the end of July. If you're buying plug plants, they'll save you a bit of faff, just plant them out when the weather's settled.

If you did start any indoors, which I don't really bother with much for fennel, you'd want to harden them off gradually before planting them out. For outdoor sown or plug plants, make sure they have plenty of room, that 15 cm spacing is crucial for good bulb development. They don't need any special support, just good, rich soil. You can grow them in big containers too, mind, if your plot's a bit full or you've only got a patio.