When a bored teenager takes the time to notice a plant, calling it “cool” and “different,” you can bet that plant is a succulent. Most succulents are not hardy to our zone 5 climate, but their amazing shapes, textures and colors make them worthy garden plants, especially well-suited to use in containers.
The plant that got my teen’s attention was a shiny, burgundy rosette perched atop a 3-foot stalk that looked like something Dr. Seuss would have drawn. Its proper botanical name is Aeonium arboreum ‘Zwartkopf’ and I brought it home in a 2-inch pot, wintered it over for several years, watching it grow taller and more awkward over time.
Besides their eye-catching appeal, succulents are relatively pest- and maintenance-free. They are easy to grow if their cultural needs are met. Their large, fleshy leaves store moisture, making them relatively drought-tolerant. The larger the leaves on the plants, the longer they can go without water. The most critical factor in success with succulents is to plant them in a container mix that drains freely. When you do water your container, make it a nice deep watering, allowing the water to flow out of the bottom of the container. A small container might require weekly watering, while a larger one could be watered every two weeks. A container planted outside might do fine with natural rainfall until the hottest days of summer. Jade plants will actually tell you they need more water. Their plump leaves will begin to pucker if the plant is too dry, making it perfect choice for an unsure gardener. Humidity affects the need to water. If the weather is sunny and dry, you will need to water more often than if the dew point is high.
Do not allow the top of the soil to dry out completely between watering. If the soil is so dry it’s pulled away from the sides of the pot, you’ve waited too long. Ideally, the roots should be contained within potting mix as moist as a wrung-out sponge. Although similar in appearance, spiky leaved agave plants can tolerate less water than aloes. Smaller-leaved sedums require a bit more water than their larger-leaved relatives. However, a mixed planting of succulents will do just fine if their watering needs are met as described above. A layer of gravel on top of the exposed soil sets succulents off well, and it also has the advantage of keeping their stems dry. Rotting from too much water is the most common pitfall.
Most succulents prefer a partly sunny location, about four hours of sun, preferably not the hottest midday exposure. Variegated and light green leaves can scorch in full sun. Darker green and burgundy leaves can generally tolerate more sun. If you are a shade gardener, more shade-tolerant species include Haworthia attenuata or zebra plant and sansevierias, commonly known as mother-in-laws’ tongue or snake plant. These species can thrive in as little as 2 hours of sun per day.
Interestingly, a light-stressed succulent, one that is getting more sun than it prefers, will display brighter coloration of the leaves. One popular succulent is Euphorbia tirucalli ‘Sticks on Fire.’ The red coloration on the ends of the “sticks” is enhanced if it is planted in full sun. Large-leaved kalanchoes, commonly called paddle plants, will have warmer red leaves if they’re given a higher than optimal dose of sunshine.
Specialist growers of succulents may recommend a more specific soil mix than the good quality soilless mixes that I have had success with. Many advocate the addition of grit, bark, coir, pumice or perlite. There is near unanimous agreement that fertilizing is unnecessary, but your plants might appreciate a watering with half strength fertilizer in the spring when you’re bringing overwintered succulents outdoors.
The range of species is vast. It includes plants hardy in our area, such as sedums and sempervivums, commonly known as hens-and-chicks. But most succulents are tender in the Pittsburgh area. For the purposes of design, succulents offer a diversity of forms and -- let’s face it, weirdness -- which few other species possess.
Succulents can be found from the best local nurseries to the ubiquitous box stores. Hopefully, when you find a plant that intrigues you, a plant tag will be included. That is not always the case. The aeonium that drew me into the world of succulents was not marked, but it was easy to grow and encouraged me to try more of these truly interesting plants. I have successfully wintered some over, simply pulling the pots in before the first frost and seeing which species survived. Jade plants and a cool gray-green Graptoveria ‘Fred Ives’ have proven hard to kill.
The real fun in growing succulents is creating compositions in containers that will enhance your garden and have great style. Succulents allow the gardener to create a vignette of plants that will look terrific from early spring until frost, complete with a range of height, color and form unequaled by the common flowery confections found in most gardens.
Dramatic, linear plants such as agaves, sansevierias and aloes look terrific planted alone atop a narrow container or urn. A row of tall zinc containers with a sansevieria planted in each, repeated on a contemporary deck, would be effective and easy-care.
Alternatively, you can add rosettes of aeonium and echeverias at the base of the anchor plant. If you like the “thriller, filler, spiller” formula for your container plantings, add trailing sedums or senecios to the pot. Sedum burrito or burro tail, Senecio radicans ‘Fishhooks,’ commonly known as string of bananas, or string of pearls (Senecio rowleyanus) all will tumble down the sides of a container. A memorable container with such trailing plants was a chubby cherub holding a planter filled with string of pearls.
As for that teenager who noticed the aeonium many years ago, his own home garden now features a single decorative container, a pot glazed in shades of brown, tan and blue/gray. It is planted with bluish echeverias, Sedum rupestre ‘Angelina’ and Carex flagellifera ’Toffee Twist,’ making for a display that is both cool and different.
Carol Papas is a Penn State master gardener. Columns by master gardeners sometimes appear in place of the Garden Q&A by Sandy Feather, a Penn State Extension educator.