Succeeding with Succulents
Container of succulents at Ruth Bancroft Garden
Photo: Catherine Caldwell
A few years ago I received some succulents as Christmas gifts. Then I proceeded to kill all but one of them. And that poor little survivor — well, it just barely survived. Being a reasonably capable gardener and house-plant nurturer, I figured it was just a matter of providing the right soil. So I headed off to the garden center and grabbed a bag of soil mix labeled especially for cactus.
Ruth Bancroft Garden
Photo: Catherine Caldwell
Weren’t cactus and succulents the same? Well, a year spent in this new soil mix did absolutely nothing for my struggling little succulent. Meanwhile, succulents were appearing all over, many in elegant containers bursting with various assortments of succulents — all in good health. That’s what I wanted to create, but clearly I needed to learn a thing or two.
The first thing I learned was on a tour of a public garden famous for its succulents and cacti — the Ruth Bancroft Garden in Walnut Creek, California. Practically the first words out of our guide’s mouth were: “All cacti are succulents, but not all succulents are cacti.” Could this explain why my succulent was unhappy in cactus soil?
Opuntia ficus-indica at the Ruth Bancroft Garden
Actually, succulents — even the ones that are NOT cacti — have a lot in common with cacti. Most cacti and succulents are adapted to dry habitats, and are found in arid regions all over the world. Most are able to store water, enabling them to survive long dry periods. The word “succulent” means “juicy” — and, in truth, that’s exactly what they are, thanks to their ability to store water in their leaves and/or stems. And that brings me to another clarification: succulents and cacti can be classified as “xerophytes” — plants that thrive in dry conditions. But if you’re a plant, being “juicy” is not the only way to adapt to an arid climate, so a xerophyte may or may not be a succulent plant. Drought-ridden California seems to be headquarters for gardens devoted to xerophytes, the Ruth Bancroft Garden being one example.
Large Agave franzosinii dwarf Ruth Bancroft herself at the Ruth Bancroft Garden in Walnut Creek, California.
By the way, if you get a chance to visit, you’ll be wowed by the size of the succulents and cacti in this famous garden where they can live outdoors all year. And what an inspiration it is to us home gardeners. That’s because it started out as a home garden and with small plants. Nowadays it serves as an educational center for those wishing to create beautiful gardens that can thrive in dry conditions.
Bear in mind, however, that the term succulent does NOT refer to a genus or species. A number of plant families include plants that have water-holding characteristics, and the more well-known ones are listed below.
Some Succulent Plant Families and their Common Names:
- Agavaceae -Agave
- Aizoaceae -Mesembs/Ice Plant
- Aloaceae -Aloe
- Apocynaceae -Periwinkle
- Cactaceae -Cactus
- Euphorbiaceae
- Fouquieriaceae -Ocotilo
- Piperaceae -Peperomia
- Crassulaceae – Stonecrop
The familiar “Crown of Thorns” (Euphorbia milii) Photo: courtesy of wikimedia
Most of us are already familiar with many succulents — sedums, ice plant (delosperma), jade plant (Crassula arborescens), the snake plant (Sansevieria trifasciata), the medicine plant (Aloe barbadensis), the century plant (Agave americana), and the flowering Kalanchoes (Kalanchoe blossfeldiana). If you’re like me, you want to try the more exotic varieties.
Cultural Requirements
The key to succulent success boils down to the right soil and the right amount of water at the right time. Let’s look at soil first.
Succulents need perfect drainage! Ordinary soil is probably not going to cut it, either. In nature, most cacti and succulents are found growing in open, well-drained sandy soil. To succeed, I was going to have to re-create these conditions in my indoor pots. A mix of one part potting soil and one part coarse sand is usually porous enough. And surprise! — there’s no need to add organic material; succulents are adapted to the “weathered soils” of their native habitats and these soils are very low in humus.
A mix of succulents by artist Wren Ross. Photo: Catherine Caldwell
My research reveals that many succulent growers have favorite formulas, but all use soil mixes that contain enough gritty material to permit rapid drainage. Some use sharp sand, others use perlite, and others use slate chips or pea gravel. A mineral of some kind is common to most soil mix formulas. But keep in mind that a pre-mixed cactus soil mix is not necessarily a good medium for a non-cactus succulent — as I learned to my sorrow. Some cactus soil mixes will stay wet too long for succulents, probably because they may not contain enough sand or other sharp mineral material.
One professional grower uses 2/3 ordinary potting soil (NO moisture holding additives) and 1/3 slate chips or pea gravel for indoor plants, and a 50/50 ratio of soil to slate chips for outdoor plants. Another recommended soil mix formula is 2 parts potting soil, 1 part perlite, and 1 part small size gravel, such as pumice, turface, or crushed granite. Remember that the sand in a mix should be coarse-grained such as builders sand or so-called “sharp” sand.
The key to success of any soil mix for succulents is crumbly structure. To test your soil mix, moisten it and then squeeze with your hands: the mixture should NOT form a lump, but instead should crumble loosely.
Water
Succulents do need water, but they cannot be allowed to sit in water, a condition that will kill many succulents. Drainage is a key, as mentioned above, so allow plants to dry out between waterings.
How often to water? That depends upon the season, or to be more accurate, with the natural growth cycle of the succulent. Basically a succulent should be kept warm and well-watered during the natural growth cycle and cool and dry at other times of the year. In our area, this means that during the winter, water your indoor succulents only once every couple of weeks. When plants are actively growing — spring and summer, for most succulents — you’ll need to water them once a week, especially if you’ve moved them outside. In spring and summer, water until it pours out of the drainholes — and of course, drain holes are essential! After a few minutes, dump out the water in the tray or dish underneath the pot. Water again only when the soil gets dry. During the dormant period, apply water very sparingly. Let the soil get dry and then apply enough water to slightly dampen the soil. Overwatering during the dormant period can lead to rotting. extension.illinois.edu
Light
Although succulents prefer lots of light, they can usually adapt to the low light of homes. For best results, give succulents bright light for most of the day, such as a south-facing window, or at least a half-day of sun as in an east-facing window. Remember to rotate plants weekly if they are bending toward a light or window.
During the summer, succulents like to be outdoors, and they’ll look gorgeous on patios, decks and porches. You may want to place them where they’ll get just a bit of shade. Some varieties are not happy with a lot of hot, direct sun.
Most succulents have very low nutrient requirements. Cacti need fertilizer only once or twice a year during the late spring or summer when they are actively growing. Use a houseplant food that is higher in phosphorus than nitrogen, and dilute it to half the recommended rate. Other succulents may be fertilized in the same manner three or four times during the brighter months.
Pests are rarely a problem for succulents, so long as they’re receiving the right amount of light and water. If they have mealybugs or scale, the problem can be controlled by wiping them off with alcohol-dipped cotton swabs.
Indoor Succulent Combination at Ruth Bancroft Garden
Photo: Catherine Caldwell
Varieties of Succulents to Try
Most of the succulents that intrigued me in California are not hardy here in central Virginia, which is why you’ll mostly see them sold as houseplants. Of course, you’re probably familiar with sedums that ARE adapted to cold, such as the popular Sedum ‘Autumn Joy’ (recently reclassified as Hylotephium spectabile), and the genus Sempervivum, which contains some winter-hardy ground covers. But the focus here is on the non-hardy types that will spend the winter inside. For starters, I suggest you look at the succulents recommended by the New York Botanical Garden. NewYorkBotanicalGarden.org/libguides (“Succulents In Your Home: Some Popular Succulents to Grow Indoors”), some of which are mentioned below.
Echeverias are mostly Mexican natives (some live in Texas and South America, too) in the family Crassulaceae, a large family containing many popular genera of succulents often found at nurseries and garden centers. Most echeverias grow in higher elevations in Mexico where the humidity is low and the temperatures rarely get hot. Soils there are well-draining, and some species live only on cliff faces and steep slopes where excess water drains off anyway. Keep in mind that these are not tropical plants.
Echeveria albicans
Photo: Ruth Bancroft Garden
Echeverias (etch-eh-Veer-ee-ah) have rosettes of white, pink, and shades of blue. Most remain a few inches high and wide. Don’t let water sit in the rosettes or it may lead to rot. Remove any dead, lower leaves.
Echeveria elegans is one of several plants referred to as “hens-and-chicks.” But it works better as a houseplant because, unlike the more common Sempervivum genus, the rosettes do not die after flowering. This plant needs the brightest light you can provide. E. elegans produces numerous, smaller offshoots surrounding the parent plant.
Echeveria derenbergii, commonly known as “painted lady,” also has small rosettes that produce many offshoots. Like most echeverias, it needs plenty of light. In the photo below, the “painted ladies” are blooming, but that’s probably because they’re in the care of a botanical garden that is providing the necessary conditions. Getting an indoor succulent to flower can be tricky. You may be able to bring cacti and succulents into bloom if you can re-create their native winter conditions. This requires good light, dry soil, and cool nights — which might be available on a windowsill.
Echeveria derenbergii
Photo: Jardin Botanique de Montréal
Echeveria lilacina has silvery-grey leaves that form a rosette and is quite small, reaching only about 6 inches tall.. This species is slow growing. Flowers are pale pink or coral-colored.
Echeveria “Strawberry Heart”
Photo: Ruth Bancroft Garden
If you’re not afraid you’ll get way too excited about succulents, take a look at frilly echeverias at the online journal Pacific Horticulture, www.pacifichorticulture.org (“Frilly Echeverias: the Fairest Succulents of Them All”).
Sedum morganianum is one I’m eager to try. It is commonly known as donkey’s tail or burro’s tail. Like its common name, this sedum resembles a long tail and is usually grown trailing from a hanging basket, which helps with the drainage issue.
Sedum morganianum, known as burro’s tail or donkey’s tail. Photo courtesy of Flickr.
Sedum morganianum in flower. Photo courtesy of wikimediacommons.
Sedum morganianum is part of the family Crassulaceae, native to southern Mexico and Honduras. It is not hardy in our area, so it will have to reside in your house during the winter. Filtered light and protection from wind are recommended.
Senecio vitalis ‘Serpents’ (Asteraceae), (“blue chalk fingers,” growing at the Missouri Botanical Garden. Photo: James Steakley
There are several popular species of senecio ( sin-Ess-ee-o), usually with tubular steel blue or grayish green leaves, often known by names such as “chalk fingers” or “blue chalk sticks.” Although most are small, a few get as tall as a foot. If they get too tall, you can pinch them back, which will promote branching.
Senecio rowleyanus (“string of pearls” or “string of beads”). Photo: Leonora Enking.
Senecio rowleyanus, commonly known as “string of pearls” or “string of beads” is a succulent vine of the aster family. It is native to dry areas of southwest Africa. Talk about a show-stopper!
Haworthia fasciata
Haworthias are particularly easy to grow indoors, since they will tolerate even lower light and less water than most succulents. Zebra plant (Haworthia fasciata) has thick, dark green, fleshy leaves that arise from low on the plant, and not surprisingly, the leaves have white stripes. Zebra plant has shallow roots, so it a does well in a shallow pot. You’ll need to repot every year or two because plants need to get rid of old roots to grow new ones. It only grows about 5 or 6 inches tall and wide.
Aeoniums are another popular genus known for their rosettes of fleshy leaves, but take a look at A. arboreum — its rosettes are on tree-like branches, that may get as tall as 3 feet in height! A recommended variety is Aeonium arboreum ‘Atropurpureum’.
Aeonium arboreum ‘Atropurpureum’
There’s more to kalanchoes than the popular Christmas gifts in the grocery stores. The so-called “panda plant” — Kalanchoe tomentosa — is another good choice for an indoor succulent.
Propagation: Want more succulents? Many can be propagated from a single leaf off the parent plant! This is true for some crassulas, kalanchoes, echeverias, sedums and aeoniums. chemung.cce.cornell.edu/resources/care-of-non-hardy-cacti-and-succulents
The popular “panda plant — Kalanchoe tomentosa
Photo: courtesy of wikimedia
Winter seems like the perfect time to focus on indoor plants. And what better time to get creative with colorful and dramatic succulents. So long as you give your succulents the proper soil, water and light, you’ll succeed. Now that I understand the needs of my struggling little succulent — which I’ve now identified as an echeveria — I feel certain the little fellow is going to thrive. So excuse me while I go mix up some sharp sand and potting soil.
My struggling succulent
Photo: Catherine Caldwell
SOURCES & HELPFUL LINKS:
Anderson, Miles. Illustrated Encyclopedia of Cacti and Succulents. Anness Publishing Ltd., New York, 1999.
“Cacti and Succulents,” Univ.Minn.Extension, www.extension.umn.edu
“Potting Mixes for Succulent Plants,” National Capital Cactus and Succulent Society, www.washington-dc.cactus-society.org
“Propagation of Cacti and Succulents,”www.ndsu.edu/Propagationofcactiandsucculents Neisen, North Dakota State University).
“Crassulaceae — Stonecrop Family,” aggie-horticulture.tamu.edu
“Cacti and Succulents as Houseplants” extension.illinois.edu/gardenerscorner
Excellent, well-written, informative article with great photos.
So glad you liked it!
Good job, Cathy! Your writing is good for my vocabulary! (Vocabularaeae vocabula)
Wow! I learned so much from this article, and especially enjoyed seeing the gardens in Walnut Creek, CA near my former home in Napa. I had a lovely succulent area in my garden there. I am sure your “poor struggling succulent” is now thriving with expert care. Thank you for this article.
I’ve found that a good home recipe for succulent soil is 4 parts potting soil, 5 parts poultry grit (i.e., crushed granite) or course sand, and 1 part perlite. Succulents are wonderful and so interesting because of the almost endless varieties available.
Thank you. Very helpful.