Haworthia is an elongated, fleshy rosette that resembles aloe. Wart-like bands of white on dark evergreen leaves give a mottled look to H. margaritifera, and a striped appearance to zebra plant, H. fasciata.
There are numerous species in this family, some with leaves so plump and shiny they’re fit to burst. It thrives in full sun and sandy, well-drained soil. Water and apply a diluted or slow-release fertilizer during growth and bloom periods.
Most Haworthia rosettes remain shorter than six inches in height, but flower stalks may rise a foot or more above the base leaves.
Grow this succulent outdoors year-round in zones 9 to 11, or in containers that may be moved indoors for winter. Check houseplants in spring, and repot as needed to maintain adequate space for expanding and multiplying rosettes.
2. LITHOPS AND PLEOSPILOS NELII
I think Lithops, often called living stone, is one of the most unusual succulents. The one you are likely to find for sale is L. bella.
Both Lithops and Pleospilos nelii are mesembs, or stone-like succulents, from the Aizoaceae family.
P. nelii, or “split rock,” is generally larger than Lithops. It has a bit of a stem or neck, and is not set quite as deeply in the ground as Lithops. It may also get more than one flower at a time, as opposed to Lithops’ single bloom.
They are often mistaken for each other, and P. nelii is sometimes (confusingly) sold under the label “Lithops P. nelii.”
In the wild, Lithops grows mostly underground, exposing only the tips of its leaves to absorb what little moisture is available.
Topping out at about an inch and a half in height, it displays the color striations and smooth surfaces of rock, betrayed only by the lush white or yellow daisy-like flowers that emerge from its fissured center.
Grow Lithops in shallow pots, or in the garden where it spreads densely, creating an earthy, textural mosaic of browns, greens, and blues. It craves gravelly, well-drained soil and full sun, and may be enjoyed year-round in zones 10 and 11. P. nelii has the same requirements for planting, and it is available in shades of green or purple.
The water requirements for mesembs are low. During winter dormancy, they requires almost none. However, during the emergence of new leaves and/or flowers, water each time the well-drained cactus/succulent potting medium or gritty soil dries out completely.
Give it full sun and room to roam, and it will tolerate even the driest of soils. This half-hardy annual can’t tolerate the cold, so start seeds indoors in early spring and sow seedlings outside after the danger of frost has passed.
Ideal accommodations include gritty, well-drained soil, and water only when leaves droop.
In return, expect lots of bright, showy blooms that boast single or double rows of petals in a range of colors from yellow to hot pink. Narrow, fleshy leaves resemble pine needles and grow on trailing stems that are lovely in hanging pots and rock gardens.
This flower is one of my childhood favorites, and is often overlooked by “serious” gardeners. It’s a fun plant for kids because unless they kill it with kindness, à la too much water, it’s almost foolproof.
There are numerous cultivars which bloom profusely from June through September. No fertilizer is required.
Portulaca is intended for the garden or outdoor containers, where it will live for one season. It is not a houseplant.
Mixed double Portulaca seeds are available from True Leaf Market. They grow as annuals in zones 5 to 11 and are perfect for containers.
Another Portulaca with which you may be familiar is P. oleracea, or common purslane. This is an edible wildflower with succulent leaves and tiny yellow flowers that has naturalized in the US from unknown ancient origins.
Like me, you may find it sprawling in bare ground in your landscape. And, while many call it a weed and consider it to be a nuisance, purslane is in fact a useful groundcover that’s rich in nutritious omega-3 fatty acids!
Sedum is an expansive flowering succulent variety, another genus belonging to the huge Crassulaceae family.
Often referred to as stonecrop, some are evergreen perennials that will grow to be two feet tall, like S. spectabile ‘Autumn Joy,’ with its eye-catching deep pink flowers that bloom from late summer through fall.
Others, like coppertone sedum, S. nussbaumeranum, are low-growing perennial groundcovers that add tons of textural interest with their quirky shapes and hues, with occasional frothy white flower clusters.
Sedum thrives in full sun in sandy, well-drained soil. Its fleshy leaves and stems are amazing water reservoirs, so only water when the soil is bone dry. It will tolerate some shade, but its preference is to bask in bright daylight.
Closely related to sedum is Sempervivum. Its perennial, evergreen rosettes are the mainstay of rock gardens in zones 3 to 6, and often all the way to zone 8.
This is one of my favorites here in northeast Pennsylvania, with an array of choices ranging from one to twelve inches in height.
Perhaps the best known is S. tectorum, aka hen and chicks, or houseleek (also a common name of Aeonium). It’s remarkable for the proliferation of tiny replicas of itself that mature and spread densely.
This is a useful and attractive groundcover choice for dry problem areas, like those along suburban sidewalks. It’s also a popular selection for roof gardens and rock walls.
Another is S. arachnoideum, the cobweb version of hen and chicks.
White filaments cover the top of each rosette as though a spider was busy spinning many, many webs. There’s always something funky to find with succulents!
Sempervivum thrives on neglect, and requires almost no watering. Simply provide sandy, well-drained soil and full sun, and it is in its element. If you garden in a northern climate, apply some mulch in early fall for an added layer of warmth.
Keep in mind that Sempervivum is monocarpal, and each hen dies after flowering. However, its chicks carry on from there.