Pig’s Ear and Other Orpines

pig's ear (Cotyledon orbiculata) Photo credit: Manuel M. Ramos / Foter.com / CC BY-NC-SA

pig’s ear (Cotyledon orbiculata)
Photo credit: Manuel M. Ramos / Foter.com / CC BY-NC-SA

There it was. A gem of the winter garden, flowering like it was the middle of May.
I am always startled by winter bloomers. Not by the occasional rose, or by winter annuals with their predictable and prosaic cheeriness, but by long-established perennials, hardly noticeable most of the year, that make a point of blooming when their fellow garden standbys are nothing but stems and leaves.
With the unspectacular name of pig’s ear (Cotyledon orbiculata), this perennial succulent brings light to sunless winter days.
Pig’s ear, like so many plant names, is a conundrum. None of its parts truly resembles a pig’s ear, although leaves may be somewhat reminiscent of auricular porcine appendages. It would make more sense to call this plant winter lantern or lampshade due to its bell-shaped orange flowers that illuminate the garden.
I could tell from the size of the specimen in front of me that it had been in the garden for a decade or more. I’ll bet it had not seen much water or fertilizer during its garden stay.
As a member of the orpine or Crassulaceae family of plants, pig’s ear does not ask for much. Crassula means thick in Latin and refers to the thick and succulent foliage belonging to members of the group, but crassulas also have a backward botanical metabolism that imparts a level of toughness not found in other plant families.
Whereas nearly all plants have stomata or leaf pores that open during the day to take in the carbon dioxide needed to make carbohydrate, a plant’s self-made food and energy source, crassulas keep their leaf pores closed during the day and open them at night. This helps them survive droughts since plants that open their leaf pores during the day lose water through these same pores and are more susceptible to drought stress.
One of my favorite crassulas is paddle or flapjack plant (Kalanchoe luciae). Its distinctively shaped leaves have a strong infusion of red along their upper margins and their prevailing green color may turn a chalky blue. This is a species that begs to be grown in containers where it can be viewed regularly, its colorful and whimsical presence a source of unparalleled ocular delight.
There are several Mediterranean spurge (Euphorbia characias) cultivars that stand out in the winter garden because of their foliage.
‘Silver Swan’ and ‘Glacier Blue’ are variegated selections with seersucker, blue-gray foliage edged in white. Euphorbia characias wulfenii has cylindrical to globular masses of chartreuse flowers. It has blue-green foliage, blooms gloriously in the spring, and lives for five or six years, producing clumps that may be divided to create new plants.
Along the west side of the Van Nuys courthouse, there is a row of drought-tolerant cork oaks. Cork oak (Quercus suber) is noteworthy due to its spongy, hydrophobic bark.
The corks you may be popping tonight come from this tree, which is grown primarily in Portugal and Spain, but also in France, Italy, Morocco, Algeria and Tunisia. Harvesting the cork, or outer bark of these trees, is a special skill done entirely by hand. Improper harvesting procedures can kill a tree.
Normally, a cork oak is allowed to grow for 25 years before the virgin layer of cork is harvested. When harvesting is done correctly, the tree is not damaged and will regenerate another layer of cork in about 10 years. There are approximately 10 cork harvests during a tree’s productive life of 150 years, while a tree’s life span stretches to 250 years.
Cork oak forests are in danger of disappearing, but not due to overharvesting or mismanagement. The problem is that corks made of plastic and silicone are less expensive than real cork and these stoppers are gaining wider acceptance, resulting in less demand for cork and subsequent neglect of cork oak forests.
Still, the lion’s share of premium wines continue to be stoppered with cork.
Cork oak itself is a fine shade tree and may be grown in all of California’s deserts. It could be planted from the Antelope Valley to Palm Springs, the only caveat being that foliage may yellow in highly alkaline soil. To mitigate alkalinity, apply gypsum to the soil around the tree on a regular basis, at least once a year.
Tip of the week
One of the easiest plants to grow and propagate is Linden’s bloodleaf (Iresine Lindenii), with its pink-magenta stems and leaves. It is suitable for indoor planting wherever excellent light is available. When grown near the ocean, it can be planted outdoors in full sun. In the Valley, it needs to be protected from cold temperatures and should be planted under trees in dappled sunlight, or in containers under a porch roof, patio or balcony cover. It lives a short time but once it reaches more than 18 inches tall, its terminal 6-inch shoot tips may be detached and rooted so that you will have a steady supply of new plants.

Photo credit: Manuel M. Ramos / Foter.com / CC BY-NC-SA

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