[wales1000]

does it mean anything if some of my broccili which is growing, the leaves have turned yellow?  many thanks.

[gobs]

Big general question with nothing to go on. Picture by any chance or some more details , please. If it's your seed leaves dying, don't bother, that's normal.

[iwantanallotment]

As gobs says, big question with lots of potential answers.

What are they planted IN, and what was there last year? Is it just the seed leaves?

Could be nitrogen deficiency, but wouldn't like to say without more to go on