Succulents Aren’t Just for the Desert Anymore
If you’re looking to diversify your product line and setyourself apart from the competition, perhaps you should consider growingsucculents. They are adapted to withstand drought by storing water inspecialized cells in their leaves, stems and/or roots. The term succulent doesnot refer to a plant family per se, but to a water-storing adaptation that isfound in many different plant families. Cacti are probably the best-knownfamily of succulent plants, but there are many other types in a huge variety ofshapes and sizes.
Succulents are increasingly popular. With water restrictionsin place across the country, there is an increasing demand for plants thatpromote water conservation. Many succulents are particularly well adapted towithstand climatic extremes, such as drought, heat, wind and frost. They aregenerally free from pests and diseases and are less prone to nutrientdeficiencies. They are also tolerant of poor and shallow soils.
Growing A Succulent
Mixed containers of succulents are a high-value product thatconsumers love because they stand up to neglect. Even when they are not inbloom, many succulent plants provide visual interest in the form of boldtextures and colorful foliage.
Although succulents may take longer to produce, theyactually thrive on reduced water and fertilizer inputs; rarely requireinsecticides, fungicides or PGRs; and are easily propagated by stem or leafcuttings, or produce offsets that can be removed and potted. Most succulentscan also be propagated by seed, but it may take a year or longer for them toreach a salable size.
To grow succulents, you will probably need to modify yourproduction protocol. A well-aerated and freely draining medium is critical.Commercial cactus and succulent mixes usually consist of equal parts coarsesand, perlite, peat or fine bark. To make your own, try mixing one partsoil-less or soil-based media with one part coarse sand and one part washedgrit, small gravel, claimed clay, pumice or expanded slate. Mixing atime-release fertilizer in the media will ensure a constant supply ofnutrients. Succulents should be allowed to dry slightly between watering. Underpotting is a good way to ensure that the roots don’t become over saturated.
To produce rapid growth and the best form and color,succulents should be grown in the strongest light possible and warmtemperatures, as they will respond more favorably to high water and fertilizerinputs. Many succulents tend to go dormant during the shorter days and coolertemperatures of winter. This is the time when they are most prone to fungalpathogens that cause rot. To keep them actively growing during the wintermonths, extend day length with supplemental lighting and keep your greenhouse warm.Maintaining a lower-than-normal relative humidity and excellent air circulationwill reduce the likelihood of disease and pests.
The century plant, or agave, is an incredibly diverse groupof rosette-forming perennials. There are agave to suit almost every U.S.climate, with cold hardy forms that can withstand single digit temperatures.While most people look at these plants as a Southwestern phenomenon, ourchanging ideas of annual are opening markets as summer color throughoutnorthern United States. Growers may need to look at buying in pre-finishedmaterial, this is a very slow crop from seed to sale —
Another misconception is that all agave are sharply spined anda problem to work with; while it may be true for most, one of the most dramaticand easily grown species, A. attenuata, is soft leaved and extremelyarchitectural. There are agave native throughout the United States, and forspecimen containers, you can’t beat these prehistoric, bold textures except byusing paddle Cacti, which is also a great idea, but will have to be anotherarticle…
Sempervivum and Echeveria
Sempervivum and echeveria are both commonly known as hensand chicks. Sempervivums, also referred to as houseleeks, are native tosouthern and central Europe. They are generally frost-hardy but tend to sufferin extremely hot and dry conditions. The leaves form low-growing, tightlyrounded rosettes in varying shades and patterns of green, gray and red. Theflowers, usually pink or purple, are held just above the foliage. These plantsare monocarpic, which means that each rosette dies after it flowers, leavingbehind a cluster of offsets. There are approximately 40 species and at leasttwice as many cultivars of sempervivum. The most commonly grown and hybridizedspecies are S. tectorum, which has gray-green leaves with red tips, and S.arachnoideum, which has tiny threads connecting the leaf tips to create anamazing cobweb effect. Sempervivum are appropriate for landscape use throughoutmost of the United States but are prone to rotting in areas with hot, humidsummers.
Echeverias are native to Central America. Consequently, theyare able to withstand high temperatures and drought better than their Europeanrelatives but are not particularly frost-hardy. The rosettes of echeveria aregenerally much larger than those of sempervivum, and the range of leaf shapesand colors is much more diverse. The foliage colors include green, gray, blue,pink, orange and red, and many are edged in a contrasting color. Some echeveriahave leaves covered with soft downy hairs, but most have a powdery or waxysurface that lends a shimmering richness to the foliage. The bell-shapedflowers, in yellow, orange, red and pink, are borne in clusters on archingstems.
There are about 150 species of echeveria, which have beenextensively hybridized to create an astounding assortment of cultivars. E.lilacina has powdery gray leaves with pointed tips, forming a tight, elegant-lookingrosette. E. shaviana has blue-green glossy leaves with frilly edges. One of themost popular cultivars is ‘Perle von Nurnberg’, which has broad, pointy-tipped,gray-green leaves flushed with pink.
The genus euphorbia has more than 2,000 species (commonlycalled spurges), about half of which are succulents. Poinsettias and crown ofthorns are two of the best known euphorbias. Characterized by tiny petal-lessflowers enclosed by brightly colored, showy bracts, all euphorbias should be handledwith caution because their milky sap (known as latex) is irritating to the skinand mucous membranes. Some spurges, such as E. horrida and E. echinus, areleafless but have swollen spiny stems that resemble a cactus. Others, includingE. obesa, form small rounded, ridged domes that might be mistaken for seaurchins. The crown of thorns, E. milii, has erect spiny stems with showy redbracts. New crown of thorn hybrids, Euphorbia x lomi, have much larger,longer-lasting bracts in a variety of colors.
All of these species are generally grown as containerplants, but many succulent spurges may be grown as landscape plants intemperate zones. E. myrsinites has spirally arranged, gray-green leaves andclusters of greenish-yellow flowers. Gopher spurge, E. lathyris, has leaveswith a white midrib and small green flowers and is reputed to repel burrowingrodents. The Mediterranean spurge, E. characias, grows to 3 feet, with erectwoody stems, long linear leaves and dense showy yellow flowers. Many cultivars ofthis species, including a variegated form, are also available.
There are several major groups of sedum with quite differentgrowth habit. The stonecrops are a fantastic group with all of the foliage,flower qualities and textural interest you could possibly ask for. Most sedumare good ground covers in the landscape and easy in containers. They root fromany leaf that breaks off and can be propagated in this way, by cuttings or fromseed. S. acre is a great perennial ground cover with yellow flowers in earlysummer for the northern states, and S. spurium and its hybrids providebrilliant purple to red-toned flowers and are winter hardy. For the southernstates, S. procumbens, S. rubrotinctum and S. mexicana perform the same role.
We trialed Sedum ‘Angelina’ from EuroAmerican this year, andit was outstanding for yellow-toned foliage and growth habit. Ball Floraplant’s’Coral Reef’ and ‘Sea Stars’ were both fine-textured and dense-growing plants.Another great group of sedum to try, which has excellent Northern hardiness, isS. spectabile. These are upright forms with fall flowering, usually in shadesof brownish burgundy to red. ‘Autumn Joy’ was the old standard and is stillreadily available, but look for purple foliage forms (‘Purple Emperor’), variegatedfoliage and dwarf types (‘Mini Joy’).
There are literally hundreds of sedum species and cultivarsout there, and they make outstanding landscape or container plants, withextremely low water requirements. I couldn’t begin to cover all of them, butyou can do an Internet search to find some that work for your operation.
Succulent Mixed Containers
I was so pleased to see that Saul Nurseries’, Atlanta, Ga.,booth at the Southeast Greenhouse Conference had some excellent examples ofsucculent mixed containers. I really think more nurseries should look at thisproduct as a way to diversify from chain retail. These succulent containers areheavy, fragile and don’t ship well, giving local marketers a real edge. Infollowing the old rule of one upright plant, one mounding plant and onetrailing plant, try using agave or yucca for the upright plant; echeveria,euphorbia and kalanchoe make excellent mounding plants; and sedum or portulacaare trailing components. These containers are a bit slow, but easy and can beplanted in anything — old tires, moss topiary and wreathes, sea shells,driftwood or custom cement containers — to make for unique and profitableretail sales.