Oregano grows wild in my garden. 18 years ago I planted a single 4-inch pot of greek oregano, in a bed I put in just for herbs that doesn’t even exist any more. I wasn’t aware at the time that in my Mediterranean-like climate oregano is invasive, and it will spread everywhere and then seed everywhere and then all you have is oregano as far as the eye can see.
When I had oregano growing in the herb bed that no longer exists, I had to work hard to keep it from crowding out all the other herbs. Now it grows all by itself along the fence lines and in the paths between the garden beds. In the winter it freezes solid and just keeps growing. Left to itself it grows a foot or so high with tiny flowers that are not that pretty but the bees really like them. If I mow it with the weed-whacker it spreads low to the ground like a ground cover, and all the cut parts take root and new plants grow where they fall. I don’t bother weeding it out of the paths between the garden beds because it doesn’t need any water, and it crowds out most of the other weeds. There are many worse things that could be growing in between the garden beds. (Dear stinging nettle: your post is coming up.)
The nice thing about oregano growing wild in the garden is that if I have any recipe that calls for it, the plant is just two steps out the kitchen door to gather. It is also trivial to dry and save. I have not bought dried oregano from the store in at least 15 years.
There are actually many different plants that are labelled oregano in the store and at garden centers: Italian, Greek, Sicilian, Mexican, Cuban, Turkish. Only the Mediterranean oreganos are actually true oregano. For example, Mexican oregano is actually a verbena and has a lemony flavor. Italian oregano is often an oregano/marjoram hybrid, and is milder and faintly sweet. For the strongest flavored and most oregano-like oregano you want Greek Oregano, latin name Origanum vulgare subspecies hirtum. If you can’t find a clearly labelled greek oregano at the garden center it also grows really easily from seed or from stem cuttings (as I discovered).
To dry it, I pick some of the nicer, younger stems with dark green leaves, bundle them with a rubber band, and leave the bundle in a warm spot for a couple weeks. I have a spot in the kitchen that works well for this.
When dry, the leaves strip from the stems easily, and I crush the leaves with my fingers through a sieve to grind it fine and strip out the remaining stems. A couple of batches and the entire kitchen smells like a pizza.
Dried oregano will keep for a year or more, but I dry and store a new batch every year to keep it fresh.
It’s also easy to dry and keep thyme, sage, marjoram, tarragon, bay leaves, lavender, and rosemary this way. Annual herbs with a higher moisture content like basil take a little more care to dry (a dehydrator or warm oven works well), and parsley isn’t worth drying because dried parsley takes like cobwebs and dirt. Now if I could grow black peppercorns I’d be all set.