ORIGANUM. Oregano. Europe, Asia. Semi-shrubby perennials of the mint family, some of them quite ornamental in foliage and flower. Most are mounding to matting in habit, with closely set pairs of round to oval, aromatic leaves. Their mint-like blossoms are carried in dense spikes, often with large, showy bracts. These are fine subjects for the rock garden, container plantings, borders and open banks. Sun, well drained soil, moderate to occasional watering when established. Hardiness varies, though all of the following will take 18oF or less.
‘Betty Rollins’. A dense mat resembling one of the low thymes. It has densely crowded, dark green leaves and displays many clusters of light pink flowers in summer.
laevigatum hybrid. This is my recent favorite among the group. The late Betty Rollins told us it was not the species itself, but rather a chance garden hybrid with an unspecified second parent. It makes dense, low clumps with evergreen (at least in our climate) basal shoots. The leaves are small, roundish and dark bluish green in color. In summer and fall it sends up a profusion of flowering shoots, with masses of purple blossoms opening in lengthy succession. Unlike some of the species which follow, it has nearly inconspicuous floral bracts.
‘Marshall's Memory’. A recent hybrid of uncertain parentage, commemorating the work of the late Marshall Olbrich. It forms a dense mat, spreading to perhaps 2' broad. Leaves are small, roundish and dark green in color. In late summer it carries many large clusters of lavender flowers, poking out from rosy bracts.
microphyllum. As the species name suggests, this species is distinguished, among other things, by tiny leaves. The stems are slender and wiry, and the flowers small but showy. The late Betty Rollins gave us a wonderful low-growing selection of the species itself, with nearly white foliage and deep purplish pink flowers. Our apparent hybrid of this species, received from Louis Saso, grows a little more than 1' tall. It has furry, grey green leaves and lavender pink blossoms.
rotundifolium. This species forms a tight central root-crown from which short, prostrate stems radiate in all directions. The leaves are nearly round and colored bluish green, tinged with purple in new growth. The flower clusters, which are freely produced from spring to fall, are showy not so much for the blossoms themselves as for the large, pale, overlapping floral bracts. These dry well and are used in floral arrangements. We are growing the typical form and two named selections: ‘Kent Beauty’, distinguished by even more compact growth, heavier bloom and pink-flushed floral bracts. ‘Rose Beauty’ was selected by Ron Lutsko from seedlings of ‘Kent Beauty’ for even more striking red tints on the bracts.
‘Santa Cruz’. The U.C. Santa Cruz Arboretum, as I hope you know first-hand, is a wonderful place, where many things come together, with interesting results. Their menagerie of oreganos is a good example. This was a chance garden hybrid–I would guess, involving O. pulchellum–which has turned out nicely. It forms dense clumps with leaves similar to those of pulchellum, and arching 8-12" flower sprays. These bear small lavender flowers which peek out from tightly set pink bracts. By cutting down the old stems, one can have several such shows each season.
tournfortii. Low and bushy, with many stems radiating from a narrow base. Densely furry grey green leaves are neatly set along the stems. Intricately branched flower stems rise up to 1’ above the foliage, displaying relatively large pink blossoms in conspicuously bracted clusters. The bracts are often rose tinged in this selection from Ron Lutsko.
vulgare ‘White Anniversary’ (‘Polyphant’). An ornamental selection of the kitchen oregano, and our token nod to those who think that variegation is somehow an improvement on “plain” green leaves. It is a low, dense mat, with crowns of short stems and broad ½” leaves. These have dark green centers and creamy yellow margins and random marbling. In summer it produces short stems tipped by dense clusters of small pale mauve flowers.