By T. Eric Nightingale, UC Master Gardener of Napa County
I have recently become interested in the plant family Aizoaceae. It is a positively huge family, consisting of many sub-families. The plants under the Aizoaceae umbrella are mostly of the low-lying, groundcover type. For this reason, they are sometimes known as carpet weeds, although I have more commonly heard them called ice plants.
Some members of this family are small, almost rock-like, in appearance. These plants are informally known as mesembs, a nickname derived from Mesembryanthemoideae, one of the Aizoaceae sub-families. The plants we casually call mesembs are not all members of this sub-family, however.
Mesembs are truly unique and curious plants. They are relatively small, with a variety of odd shapes, colors and textures.
One type of mesemb you may recognize are the so-called stone plants, or Lithops. Lithops do in fact resemble the rocks among which they live, providing them with useful camouflage. They are native to arid southern Africa, where they survive on little water.
Lithops have evolved to hide from thirsty animals, as well as to better store their water. They do this by growing mostly underground, the tops of their leaves almost flush with the surface of the earth. This way, they are easily overlooked by predators and also shield themselves from much of the day's sun and heat.
The tops of their leaves are flattened and semi-translucent, allowing light to enter the inside of the plant, where it is used for photosynthesis. What a truly amazing adaptation.
Mesembs of the genus Aloinopsis are some of my personal favorites. The stubby leaves on these plants have odd, bumpy dots on them. The result is either a jeweled look or something resembling the texture of a dog's nose. To me they have always looked somewhat alien, as if they initially evolved among the rocks of Martian hillsides.
When planted among other succulents in a garden, Aloinopsis may easily be overlooked. This modesty changes in winter, however, when they flower. The yellow, orange or pink blooms shine vibrantly in the sun and are truly eye-catching. While they are generally similar to daisies in shape, the stamens of these flower form a cone at their center—another way that Aloinopsis is an attractive oddity.
Another of my favorite mesembs is Oscularia deltoides. It is a sprawling groundcover, almost vine-like. I like to plant it at the edge of a pot, letting it spill over. The leaves are an attractive blend of gray, blue and green and contrast nicely with the slightly reddish stems.
When I first saw O. deltoides I did a double-take, asking myself what I had just seen. The triangular, toothed shape of the leaves made it look more like a crystalline growth of some sort rather than a plant. I have also heard it compared to coral, a resemblance easy to see when it becomes large.
This mesemb is possibly one of the easiest to grow. In my experience it needs little water and seems to revel in hot sun. During the spring, when the plant is practically covered in pink blooms, it quickly becomes the focal point of the garden.
By now everyone in California has heard of the benefits of drought-tolerant gardening. Succulents do double-duty, however, in that they are also ideal for fire-wise landscaping.
As they are especially squat and water-retentive, mesembs are an ideal addition to any California garden. While some gardeners consider them more challenging to care for than other succulents, that's only because they have different needs.
Most mesembs have a short dormant period, either in winter or summer, when they need almost no water. If you water them then as you do the rest of the year, they may rot. They generally like a lot of sunlight but some are prone to burning if exposed to late-afternoon sun. And of course, as with other succulents, mesembs need loose soil with good drainage.
Once you get to know your plant, care is easy and maintenance is fairly low. All you have to do is relax and appreciate what these unique succulents bring to your garden.
Free Talk: UC Master Gardeners will discuss “Growing Summer Vegetables” at the Napa Public Library on Thursday, March 7, from 7 p.m. to 8 p.m. Learn what you can grow in the summer, what to plant and when, and how to have a harvest all summer long. No registration required.
Workshop: The U. C. Master Gardeners of Napa County will present a workshop on “Growing Spring and Summer Vegetables” on Saturday, March 9, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Do you want nutritious, easy-to grow and utterly fresh food from your garden this spring and summer? Learn what the garden needs to successfully produce spring and summer vegetables from seeds and plant starts. In addition to growing basics and hands-on activities, this program includes watering, fertilizing and harvesting tips, with a dash of Integrated Pest Management for pest and disease control. The delight of growing your own groceries is matched only by savoring them at harvest. Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
Workshop: The U. C. Master Gardeners of Napa County will present a workshop on “Summer Vegetables” on Sunday, March 10, from 1 p.m. to 3 p.m., at Yountville Community Center, 6516 Washington Street, Yountville. Get tips for growing your own summer vegetables. Learn some basics, get keys to success, and do hands-on activities to learn about new varieties and review old favorites. Enjoy healthy vegetables taken straight from your garden to your table. The delight of growing your own vegetables is matched by savoring them at harvest. Online registration or telephone the Parks & Recreation Department at 707-944-8712.