The more humus you have in your raised bed the better as this helps the soil to retain moisture. The best types are, some soil, well rotted animal manure, old rotted straw, compost or any other rotted organic material you may have. This is important because raised beds have very good drainage and you don't want your bed to dry out, as carrots grow sweeter and less fibrous in moist soil.

Here are some tips to help you successfully grow carrots in a raised bed vegetable garden. It is a good idea to mulch around your vegetables with organic material, which will help stop the weeds growing as well as retaining the moisture for the plants.. The first two tips are especially important for growing straight sweet carrots. Make sure you break up any lumps and remove any stones that may be in the bed because they could stunt the growth of the carrot by not allowing it to grow straight down. The type of soil or growing medium is very important for carrots.

Properly prepare the raised bed where you are going to plant your carrots by making sure that you have at least 30 cm or 12 inches of fine loose soil.