Beets are considered a root crop, but the leaves are edible too. Probably the hardest thing about growing beets is thinning the plants.
Beets
Carrot seeds are also tiny and slow to germinate. Sow some radish seeds among your carrots to help identify your rows.
Carrots
Horseradish is very easy to grow, but a little goes a long way. Unfortunately, it can be hard to grow just a little horseradish.
Horseradish
Onions are fairly easy to grow. It is planting them that takes a lot of work. You have three options: You can start them from seed, transplants, or sets, which are tiny cured onion bulbs.
Onions
Parsnips grow well in most areas and will store for months, even getting sweeter with a little chilling.