Rainbow chard

This is Swiss chard (Beta vulgaris subsp. vulgaris). This is a very good plant because:

A lovely beautiful vegetable/ornamental. It can be sowed early and late in the season as it grows quick. Thinnning might be required, since the plants can grow quite big. The young plants can be confused with beets (they are closely related)

You can learn more about this plant here.

This is a tomato plant (Solanum lycopersicum). This is a very good plant because:

A classic vegetable, essential to many cuisines. Very easy to grow from seed, and if you are a real pro, you can attempt grafting it too! A very hard-to-kill plant that you can train and prune however you want. It will leave a smelly, greenish brown residue on your fingers so wear gloves.

You can learn more about this plant here.

This is a pea plant (Pisum sativum). This is a very good plant because:

Peas are the first crop to sow in early spring. They love the cold and the early morning dew. Before the pods start to grow you can snack on the young shoots (just make sure not to halt stem growth). There are different varieties for pods (mange-tout) and seeds (garden peas, petite pois) but you can eat the young pods on all varieties

You can learn more about this plant here.