Garden Sorrel: This perennial comes up in April and is a welcome addition chopped into a salad. It is a bit sour and lemony. You can also make a soup. Many garden centres sell plants.
Welsh Onion: A perennial green onion that self-seeds (remove seed heads to avoid too many plants). You can get seeds from Richters, Brother Nature, A'bunadh Seeds and maybe local garden centres.
Lovage: This perennial plant is about 3 feet tall and wide (flower head goes up to 6 feet), so you’ll have way more than you need for soups or as a herb. It’s a lovely plant though, and you can cut it a couple of times to add to the compost. Here is a blog post with recipes, from a fellow European who also knows it as Maggikraut. Seeds and plants may be available locally or you can order seeds from Richters or West Coast Seeds.
Orach: This plant is not perennial but is considered an annual weed and can be found in the river valley. It needs to be controlled as it self-seeds vigorously, but it does not spread by roots. The stalks are about 5 feet when left to grow, and you can find both green and purple orach. I grow it in a large box and pinch it back regularly. It is delicious fresh or lightly steamed. When we have other plants to eat and it wants to flower and go to seed, I allow some of the seeds to drop for next year, and compost the rest. Collect seeds in the wild or order them from one of these companies.
Lemon Balm and Oregano: These herbs are easy to grow. Lemon balm makes lovely tea and can be added to salads in small amounts. Oregano comes back even in the toughest conditions and moves to places where it like to grow. Both herbs are great for pollinators.