Cauli's failed again

Hi .. last year not one Cauli came out well ... this year bought a dozen plants ... all seemed to be going OK, nice hearts forming.
Then the hearts just seemed to go from being a solid ‘brain’ like clump to loose, and some have even shot up .... which I assume is what is termed bolted.
Pics attached (sorry about quality used phone)
I have had the worse June on record .. so it is certainly not to do with extreme warmth or sunshine.
Where am I going wrong .....?
Also have 3 varieties of cabbage in and they are doing fine.

 

My sympathies Sargan. They are a mystery to me too.

 

Never was a great grower of summer caulis, just my guess.

I've heard they dont like root disturbance unlike most brassicas, so need to be pot grown, and planted out with least disturbance as possible.

 

According to the Vegetable and Herb Expert:

http://www.amazon.co.uk/The-Vegetab...5460/ref=sr_1_1?ie=UTF8&qid=1340918544&sr=8-1

The most likely cause of this for caulis is that the ground is too loose. Apparently they really need well compacted ground.

 

I have been told that caulifower grow best in fields and are very unrelaible in the garden, this would support the theory of compacted ground as tractors and heavy cultivation equipment compact the soil in fields

 

Only summer Cauli I've grown with success is Candid Charm. That does a really good job of making a good head IMHO. Firm ground is important but I've not always bothered. Don't sow them too late either, the heat of Summer makes them do less well for me.