Many cool weather crops belong to the genus brassica in the mustard family, brassicaceae. The members of this genus are collectively known as cruciferous vegetables. They get this name from the Latin word Cruciferae which means “cross-bearing”. This is because their flowers consist of four petals and resemble a cross.
Almost all parts of some species or other have been developed for food, including the root (rutabaga, turnips), stems (kohlrabi), leaves (cabbage, kale), flowers (cauliflower, broccoli, Brussel sprouts), and seeds (many, including mustard seed, and oil-producing canola). Some forms with white or purple foliage or flower heads are also sometimes grown for decoration (ornamental cabbage and kale).
Brassica vegetables are very healthy. They contain chemical compounds known to help aid DNA repair in cells, help reduce cancer risks, and also boost you immune system. However, many people find that brassica vegetables are bitter. It turns out that there is actually a genetic basis for kids not wanting to eat their Brussel sprouts. A dislike for cruciferous vegetables can be due to the Brassica species containing a chemical similar to phenylthiocarbamide (PTC), a chemical which is either bitter or tasteless depending on one's genetic makeup.
Cruciferous vegetables are all cool weather plants that do well in the spring and fall. Some ornamental cabbage and kale varieties actually become more vibrant as the temperatures grow cooler. If you would like to plant a fall garden or cold frame these are the perfect veggies to add.