Tips & Techniques for Growing Carrots
Growing Carrots
Varieties of Carrots
Carrots are easy to grow and are very healthy containing vitamins A and B complex.  Yon can eat them raw or drink their juice.  There are several varieties available with different charteristics.  The most typical is orange colored but white, red, yellow and even purple exist.  They vary in size, taste and texture.  Some varieties produce long pointed roots while others are cylindrical in shape.  Nantes have improved flavor and texture.  They are crisp, tender and sweeter with little or no center core.  You may want to consider the type of soil in your garden when choosing a variety to plant.  Carrots like fertile sandy soil.  If the soil in your garden is heavy with a lot of clay, you may want to select a variety with shorter roots.
Preparing the Soil
Since carrot seeds are small, the soil needs to be loose to a depth that will allow the carrots to grow unimpeded.  If your soil is heavy, you may want to till in some compost to loosen it before planting. You shouldn't use a lot of high nitrogen fertilizer.  Too much nitrogen can deform the carrots and impact their taste.  Till until the soil is loose to the desired depth and mark off rows.  Using a hoe, make a straight shallow trench.  The seed can then be sowed in the trench.  You can locate carrots almost anywhere in your garden.  They are not particular about their neighbors.  Carrots are compatible with most garden plants including onions.
Planting Carrots
Carrots do best in cool weather.  Therefore, they should be planted early just after the last frost.  Carrots can be grown in rows or beds.  I prefer planting them in rows to make weeding and harvesting easier.  Sow the seeds in a shallow trench and cover them with approximately a quarter of an inch of dirt.  If they are planted too deep, they will not be able to push up through the ground.  Be careful not to sow the seed too thick.  You want a good stand but not so many plants that they will not produce nice size roots.  To avoid sowing the seed too thick, seed companies offer pelleted seed but they cost more.  The seed are coated to make them larger.  If you accidentally plant carrots too thick, you can thin them by pulling up some plants as you weed the row.  The soil will need to stay moist but well drained until the seeds germinate. 
Weeding & Plant Maintenance
If you planted carrots in rows and made the middles slightly wider than your tiller, you can remove the weeds from the middles with a single pass of your tiller.  Since carrots are planted close together, you will need to pull most of the weeds that come up in the rows.  You should till and pull weeds two or three times while the carrots are growing.  After the plants get 4 or 5 inches high, you shouldn't have to do any more maintenance, except maybe watering them during dry spells. 
Controlling Diseases and Insects
There are several diseases and pests that attack carrots.  The most common pest is the carrot fly which produces grubs that eat holes in the roots causing them to rot.  Fortunately, I have been able to grow carrots without much of a problem from diseases or insects.  Deer eating the tops has been my biggest problem.  As a result, I fence in part of my garden using seven foot heavy duty deer fencing and include carrots within the fenced area.  If you find that a fungicide or insecticide is needed, make sure you pick one for the specific problem and that can be used safely on vegetables.  You need to be especially careful when applying chemicals to edible plants like carrots.  Always read and follow the directions on the containers. For specific details on controlling diseases and pests, click on the "Gardening Resources" tab and go to the Sources of Information on Vegetable Garden Diseases and Pests.
Carrots can be harvested any time after the roots are large enough to eat.  They taste better if picked before they reach full size.  If the soil is loose, you should be able to pull them up.  If not, you will have to dig them.  Carrots can be stored to eat during the winter.  If you are keeping them in the refrigerator, break off the tops, wash them and dry them with a cloth.  For longer term storage, break the tops off but don't wash them.  Place them in a container filled with sand and keep them in a dark cool place, e.g. a cellar.  Carrots are best eaten fresh or canned.  They seem to lose their texture and flavor when frozen.