I'm with you Mick63. I also live in the N.W. and I can't grow the damn things either !

I was talking to somebody on the allotment about growing carrots and he said they is two main problems getting the seed to germinate and carrot fly once they have germinated what you need to do is really put a lot of seed down to increase the chance germination and also sow radish with them these will germinate far quicker than carrots in about a week so at least you know where the carrot seeds are also when the carrot seed do germinate the radish will help to pick out the weak carrots and to plant new seeds where the is patches in your rows once you have achieved this remove the radish and all should be well. Carrot fly use enviro mesh this is available at garden centres and eBay

http://www.organicgardeninfo.com/growing-radishes.html

You also need a light sandy soil with an extremely fine tilth otherwise your carrots will fork. Do not use any compost or manure in the soil you are going to grow carrots in.

Well I have tried lots of ways over the years and the best results I have ever had was in the greenhouse bed.

Last year I had a bit of a disaster in growing my requirements of sweet peppers ( bad compost - another story) meaning; I had a spare bed so I stuck carrots in there and they were brilliant.

I agree with the germination issue but this is usually down to temperature and I find many people tend to sow too early.

I will never sow outdoors before the end of May but usually it is mid June before I get round to it, and I don't have any problem with germination.

Once I have sown them I cover the area with a fleece tent and this remains over them until harvest time.

Note; Growing them in the greenhouse allows you to forget about this task.

If your soil is a bit on the rough side sink your spade in a spit deep and wiggle it back and forth to form a 'Vee' trench, fill this with seived compost then sow your seeds into that, give it a good soaking before sowing.

This link might be of assistance;

http://www.thegardenersalmanac.co.uk/Data/Carrot/Carrot.htm

I grow carrots in 15 foot long rows.
I sow early April. My method is to take out about 2" of soil at 5 " intervals along the row using a bulb planter so you end up with about 30 holes per row. These are then filled with any compost, finely sieved, firmed down, not to hard. Then in each of these filled holes I sow 4 seeds.
This takes a bit longer than sowing normally along the length of the row but it saves a lot of time thinning and weediing, and germination is always good.
After sowing, i use a fleece over the cloche on the carrot bed, replacing with mesh in May.

This year I am growing some in large, deep pots. I have rarely managed to get anything to germinate in past years, but they are up and away already in the greenhouse, and in a few weeks I shall be thinning them and putting them out in the sunshine (when we get any!) It's better than nothing!

The adult fly lays its eggs on the carrot as it starts to grow.