different sized carrots

I sowed late carrots back in July and tried pulling a few today. They are in a raised bed and on one side the carrots are fine for eating (plumped up and about 3" long), the other side they're miniscule!!!
I did 3 types, Giant Red are great, Sugarsnax on one side are great but the other Sugarsnax and Autumn King haven't grown more than a centimetre. All the foliage is the same. I'm very disappointed with the Autumn King.
I didn't thin and perhaps one side is more congested than the other.......
They are also very dry. Should I have been watering more? Could the drainage be better on one side or something? Would a good water help? We're quite sheltered here....will they keep growing?
I haven't got fly because they're under netting and I think late plantings tend to get away with it anyway but the surprise was no slug damage either! The earth was probably too dry and scratchy for them.
So the larger carrots were absolutely perfect which I have never achieved before.
I shall definitely do a late planting again but it would be interesting to know your thoughts on the failures.........

I give them fbb and my compost when planting but I always thought you didn't water or feed carrots too much because then they grow down to get moisture.
Learn something every day......

I think you will find that most times you don't need to water when planted into the ground but in raised beds you are starting well above the water level in the soil, so you need to water untill the root can get down into the ground soil.

Having said that, I wouldn't have expected such a big difference in growth in the same bed.

You can sometimes get a big difference between carrots in the same row, so maybe its a germination problem but then the top growth wouldn't be the same.

Sorry not much help, we'll have to wait untill somone with more knowledge comes along.