It’s not too unusual for closely related plants to have different purposes. There are ornamental and edible kale selections, plums and peaches grown either for their fabulous springtime bloom or their juicy summertime fruits, and even a couple of edible thistles, like artichoke and cardoon, with more ornamental cousins like the Scottish emblem. One such genus is Origanum, which contains several culinary and medicinal herbs, as well as a couple of drought-tolerant ornamentals.
The most familiar of these, of course, is the popular seasoning known as oregano (Origanum vulgare). So popular is this Mediterranean and Asian native that it has traveled around the world and become an essential herb in the Americas, as well. Cuisines from Italian to Mexican rely on it for a pungent kick that is often paired with tomatoes and other solanaceous vegetables like eggplant and chili peppers. Another common name for this species is wild marjoram.
Sweet marjoram (O. majorana) is also a native of the Mediterranean (and nearby Turkey). In Italy, the kitchen herb may actually be a hybrid of this species and is preferred by many chefs. Another marjoram, O. onites, goes by the name of Cretan oregano (you see the problem with common names for these species that cross national barriers). Another pretender to the name, usually called winter marjoram, is actually another species altogether: O. dictamnus subspecies viride. The subspecies dictamnus of this particular oregano has been called dittany for millennia and is still used medicinally in Crete and as one of the signature flavorings in vermouth. Hippocrates (the father of medicine) was the first to promote it as a digestion aid and apply its anti-bacterial properties. There is one more species, O. syriacum, which is the hyssop of Biblical literature.
Well, so much for head-spinning common names for the savory and medicinal variants; there are also a few oregano species that serve as great additions to Mediterranean-style gardens. Where the goal when growing cooking herbs is generally to harvest them before they put their energy into flower production, the next subjects are handsome at a later stage in their life. With larger flowers and colorful bracts surrounding them, they make excellent subjects for attracting beneficial insects, as well as bringing subtle color into the garden.
Dittany of Crete (Origanum dictamnus) is perhaps the most readily available. It is sometimes called hop marjoram for its resemblance to that beer additive. The leaves are woolly white and form a mound a little less than a foot high by as much as two feet wide. In summer and into fall, the flower stems emerge from the foliage with pinkish flowers enclosed in pale-green bracts. Specialty nurseries may carry a couple of other species of handsome oreganos. Look for O. libanoticum, which works cascading over the top of a wall or in a hanging basket. There are a couple of named selections of O. rotundifolium with larger and showier bracts. Some of them, like ‘Kent Beauty,’ have bracts that start out pale and age to a deeper pinkish shade as they age. In fact, some of these are handsome long after the flowers have faded, and the spikes can even be used in dry arrangements. All oreganos grow best in well-drained full-sun sites. Many make excellent container subjects, as well.