Carrots 

Soil Preparation
Early carrots require deep, sandy loams soil that will warm up quickly inthe spring; it must also be well drained; main-crop varieties can cope with heavier soils.The soil must be prepared the season before the crop is to be planted, freshly manuredbed will make the roots fork instead of growing long and straight.

Add manure andcompost at the rate of 4 oz. (120g) to the sq. yd. in the autumn of the previous season, digover heavy soil and allow it to stand rough through the winter; it will then be easily forkeddown in the spring.

Sowing
Carrots will not germinate if the soil is too cold or too wet. March is normally agood month for sowing carrots but the position should be sheltered and sunny. The alternative is to use cloches to help warm up the soil,
By positioning them over the bed where the carrots are to be sown in early march, the soilwill have a chance to warm up before sowing takes place.

The cloches can then be left inposition even after sowing if the weather has not improved. Do not sow all the seeds at thesame time; make successional sowings with about 2 weeks between each sowing until themiddle of April.

The seeds need to be sown about ½ in. (12mm) deep, if it is mixed with alittle dry sand it will be easier to sow thinly. After the mix has been sown into two shortrows it can then be raked lightly to cover the seed.

Carrots can be stored and used in the winter months and for those they should be sownabout the middle of April at a slightly deeper depth of ¾ in. (19mm) and about 15 in.(381mm) apart. The main sowing period comes in late July. Choose the quick-maturingvarieties to make sure that the tender young roots are ready to pull in the autumn andearly winter.

One good point about a late sowing is that it tends not to be troubled by theformidable carrot fly, which is at its worst in early June.

Growing Timing To Avoid Carrot Fly
Sowing can take place as early asFebruary/March if fleece is being used, this will mean that the carrots can be lifted in July.Therefore the soil will be cleared before the second generation of larvae develop.

Seed can be sown in early June, therefore the carrots will be relatively young at laying time andmuch less attractive as the odour which attracts the fly in the first place has yet to develop.The carrots should then be lifted at the end of October/November, leaving the groundclear with nothing for any larvae to feed on.

Take great care to sow thinly, which will makeit unnecessary to thin out later for this action too helps to release odour that will be aninvitation to passing flies.