[Benny130]

There are what I think are onions on the new patch. They must have been planted very very early!? But looks like flowers developing. Not sure why or if anything ca be done?

[Enfield Glen]

Its the result of that hot try spell, Just pinch out the flower head and they will be OK, the longer you leave it the harder that part of the onion will become. I

[mumofstig]

Sniff them if it's onion use them in stir-fries, cos they won't make bigger bulbs
If it's garlic also cut the flower stems out (called scapes in garlic recipes)  but leave the bulbs as they will continue fattening up 'til harvest time 

[Yorkie]

If it's a patch that's new to you and you don't know when these were planted, then they are most likely to be onions planted for last summer, which weren't harvested and are now going to flower in their second year.

As Mum says, check by smell as to whether they are garlic or onions, but I suspect they're last year's onions.