Sorrel will grow itself once you plant it. It is a tough perennial which will self-seed if allowed to. It will overwinter and flower, but I wouldn't call it bolting because flowering does not indicate the end of its life. I have a plant which arrived by itself and must be at least 15 years old. It is nothing like as difficult to grow as spinach. More like dock in terms of character.

OP says 'can't find it online'. Go to Google, click shopping (On my screen it is top right near center.) and enter Sorrel. Is this not what you are after?

Thanks Flora uk. I've got it growing in a large container because I heard it can take over the garden. Once it flowers does it go bitter? Should I collect the seeds and resow for a younger plant or just continue to harvest the leaves after flowering? The seeds were a pain to germinate so I would rather continue harvesting from the plants I've got.

Albert, I ordered the seeds over the summer but it came with no info about the plant or how to grow it. I did find a couple websites that had basic info like what season to grow it in and that it requires sun but I needed a little more specific info.

It's very easy to grow. Stick it in the ground and pick leaves when you want them. They have a nice, lemony flavor. Very good used sparingly in salads, or as an ingredient of sorrel soup.

It doesn't spread much in the garden, but self-seeds readily. So pick off the flower stems before they go to seed. I've found it much easier to overwinter it in the ground than in pots. It's a perennial. Mine's been coming back for six years.

It does not spread if you keep cutting the flowering stalks. It is as trouble-free a plant as they come. Even horseradish will fail in a low-N, sandy, dry, shady location. But sorrel has been there for 12 years... here it is only used for sorrel soup in April and in November.