Fennel bulbs

scmfell

For the last few years I've been trying to grow bulb fennel, "Victorio". They germinate, (in pots then transplanted) and grow well, but they do not form nice round, white bulbs. The plants are very elongated and very thin and remain quite greenish. Lots of nice fronds but little else. If left too long to "fatten" they become very tough and inedible. 

Obelixx

They need quite a bit of water to produce fat, succulent bulbs and the quicker they do that the less tough they are.

Skylarks

@BobTheGardener advice is not to sow the seeds until later after the longest day. They are daylight sensitive, so sowing them too early in the year results in them getting elongated and no bulb. 

I grew Florence fennel for the first time last year following his advice and I got nice fat bulbs around Sept or Oct time.

Obelixx

I used to buy them as plugs in Belgium and plant out in spring after the frosts.   They were good and very tasty.

I have also grown them from seed sown in July and had success.   The trick is to give them good soil and plenty of water so they grow quickly and fat and juicy.