Succulents are an ever-popular plant choice for outdoor gardens and indoor home decor. They have interesting and unique-shaped foliage in a variety of colors, and many of them flower. They’re easy to grow and can withstand neglect, so they’re a great choice for beginners, whether outdoors or as houseplants. If you like the idea of having greenery in your home but haven’t had great success with houseplants in the past, succulents may be the plants for you.

In regions where winter temperatures stay well above freezing, just about any succulent variety can be grown outdoors. However, if you live in a region that experiences heavy frosts or winter freezes, you’ll need to be more selective and look for cold hardy varieties for your outdoor garden. Any variety can be grown indoors as a houseplant, where growing conditions can be controlled.

There are many succulent varieties available commercially. Some are species native to countries around the world, including the US. Others are cultivars bred from native species to enhance particular traits such as leaf shape or color. You will find many of the common species and cultivars at garden centers, while other more unusual species tend to be harder to find.

In this article we’ll review the different types of succulents and their care, then explore some of the unique and interesting varieties on the market today.

Types of Succulents

Succulents are native to a range of habitats, including deserts, grasslands (including alpine areas), and tropical regions. Most of them share the characteristic of thick fleshy leaves, a preference for bright light and a need for well-draining soil. However, their specific growing requirements vary depending on their native habitat; desert, alpine or tropical.

Each variety has internal biological adaptations to survive their very different specific environments. These adaptations include differing root structures, water storage mechanisms and leaf structures. 

Desert succulents have adapted to thrive in harsh environments with extreme temperatures, drought and well-draining nutrient-poor soils. They need low humidity, intense sunlight and infrequent watering. They have deep root systems to seek out water or they grow low to the ground where temperatures are less extreme. Examples of desert succulents include aloes, some sedum and cacti.

Grassland succulents have different adaptations than the desert succulents. They prefer more moderate temperatures, in environments with limited inconsistent rainfall and well-draining nutrient-poor soils. They have shallow root systems to quickly take up moisture before it’s lost to evaporation. Examples of grassland succulents include Echeveria and Crassula.

Tropical succulents are more tolerant of moderate humidity than their desert cousins and prefer bright filtered sunlight (or part shade.) They need more frequent – but still limited – watering than other succulents. Tropicals are often epiphytes (growing on other plants rather than in the soil) and “understory” plants (growing beneath the cover of taller denser vegetation.) Examples of tropical succulents include Snake plant, hoyas and air plants.

For the purposes of gardening, succulents can be divided into two categories: Cold hardy (outdoor) and frost tender (indoor). The difference between them is their tolerance of frost and cold temperatures.

Cold hardy succulents are those that can safely be grown outdoors in regions that experience winter temperatures below freezing. In contrast, frost tender varieties can’t tolerate temperatures near or below freezing. These varieties are more often grown indoors as houseplants.

Cold Hardy (outdoor) Succulent Varieties 

Cold hardy succulents are those varieties that can survive freezing winter temperatures. Many succulents tolerate light frost and temperatures a few degrees below freezing for short periods, but cold hardy varieties are even more cold tolerant. These varieties can survive temperatures down to as much as  – 40 degrees, (F or C). That’s why this group is sometimes referred to as the “outdoor” succulents.

Growing Conditions For Outdoor Succulents 

Cold hardy succulents are varieties native to dry alpine habitats; no extreme summer heat and winter temperatures below freezing. They don’t tolerate extreme heat and intense sunlight the way their desert cousins can. Cold hardy succulents prefer direct morning sun – or even dappled shade – and protection from intense midday sunshine.

All succulents need well-draining soil. This is especially important for succulents growing outdoors in colder-winter regions. Wet soil makes plants more sensitive to cooler temperatures; cold and wet winter soil can be the kiss of death for succulents.

Cold hardy succulents can be grown in regions with compatible winter conditions. They can also be grown indoors as houseplants and transitioned to grow outdoors for the summer.

Frost Tender (indoor) Succulent Varieties 

While cold hardy succulents can safely be grown outdoors where winter temperatures fall below freezing, frost tender varieties can’t tolerate those temperatures. Some can be grown outdoors in temperatures down to 40 degrees F (4 C) – with a few varieties hardy down to 28 F (-2 C) –  but frost tender succulents are more often grown indoors as houseplants. Desert and tropical succulents are considered frost tender and are most often grown as indoor houseplants.

Growing Conditions For Indoor Succulents 

All succulents grown indoors need a container with good drainage, well-draining gritty soil (e.g. those labelled for cacti or succulents), and a spot with at least bright indirect light. Some need a few hours of direct sun throughout the day; morning light is best. Most succulents need to be watered infrequently, with the soil left to dry thoroughly between waterings.

Succulents, as a rule, don’t need a lot of fertilizer. In their native habitats, they grow in gritty nutrient-poor soils. Outdoor garden soil will usually provide them with sufficient nutrients. Container-grown succulents that aren’t repotted every year with fresh soil benefit from an application of dilute fertilizer once a year at the beginning of the growing season. Less is best, and over-fertilization will result in excessive weak growth or damage to the plant.

All that said, there are exceptions to the general requirements, so always be sure to learn about the specific needs of whatever succulent variety you choose to grow.

Indoor succulent houseplants can have their containers moved outdoors for the summer once nighttime temperatures are reliably and consistently above 50 F (10 C). This is often the only way you might see them flower. However, these houseplants must be gradually transitioned to the outdoors so they can adapt to their new growing conditions. The containers must then be brought back indoors in the fall before temperatures drop below 40 degrees F (4 C).

Interesting Frost Tender (Indoor) Varieties

The following list includes some of the interesting and unusual cold tender succulents sold widely as houseplants. They aren’t frost hardy but may be grown outdoors in regions with milder winter temperatures. 

Thanksgiving Cactus (Zygocactus truncatus), Christmas Cactus (Schlumbergera buckleyi ) and Easter Cactus (Rhipsalidopsis gaertneri)

There are three tropical succulents that look very similar but are often mislabeled: The Thanksgiving cactus (Schlumbergera truncata or Zygocactus truncatus), the Christmas cactus (Schlumbergera buckleyi) and the Easter Cactus (Rhipsalidopsis gaertneri). Their common names refer to the approximate times of year when they flower. They are all members of the cactus family (Cactaceae) but unlike cacti native to desert habitats, these three are tropical cacti native to tropical forests, and have very different growing requirements.

These tropical cacti differ from the desert members of the family.  These succulents are native to shady rainforests of southern Brazil, rather than hot arid regions. They are epiphytes, meaning they grow in the crevices of trees with decaying plant material, not in soil. They prefer more shade and like their soil kept evenly moist.

The plants we see full of flower buds for sale in florists and garden centres in November, usually labeled “Christmas cactus” are, in fact, the Thanksgiving cactus (Schlumbergera truncata). The true Christmas cactus is Schlumbergera x buckleyi, but it isn’t often available because it blooms in late December into January (too late for the commercial holiday market.)

The third plant is the Easter cactus (Rhipsalidopsis gaertneri). As its name suggests, it blooms in April/May.

They all bloom at specific times of year in response to reduced daylight hours. They’re known as “short day plants” (or long nights) and require 6-12 weeks of days 12 hours or shorter, which starts around mid-October. (Commercial growers can delay flowering with the use of artificial lights to simulate extended daylight). Easter cactus is triggered to bloom as the days begin getting longer following several weeks of shorter days.

They all have flat segmented stems (no true leaves) and look very similar but have subtle differences in the shape of each segment. The Thanksgiving cactus has pointy claw-shaped tips along the edges of each segment. On the Christmas cactus these tips are more rounded and tear-drop shaped. The Easter cactus segments are more scallop-shaped without distinguished points, and have fibrous hairs growing from the leaf joints.

These plants  are grown for their showy long segmented tubular flowers that grow from the tip of each stem. Depending on the variety, the flowers may be light to dark pink, white or red. Dead-heading spent flowers will encourage more blooms.

Echeveria ‘Trumpet pinky’; Echeveria ‘Piggy nose’

There are several varieties of Echiveria [LINK to Articel #6]. They are similar-looking to the cold-hardy Sempervivums (see below), with leaves that grow in a rosette. Echiveria are sometimes labelled with the common name Hens and Chicks but that name is more correctly applied to the Sempervivums. The main difference between the two  is their cold tolerance; Echiveria aren’t frost hardy whereas Sempervivums can survive temperatures well below freezing.

Most Echiveria leaves are spoon-shaped with rounded tips. They come in soft colors from silver-grey, blue-green, pale green, pink, orange and two-toned. The more light they get, the more vibrant their coloring will be. Most have foliage covered in a thin white waxy coating and a few are covered in a thin coating of fine silvery hairs. 

One particularly unusual – and rare – variety is Echiveria ‘Trumpet pinky’. It forms an upright rosette of unique thin leaves that curl in on themselves to look like trumpets standing on end (or sometimes little piggy snouts!) The leaves are silvery blue-green with maroon tips and take on a bright pink coloration in strong sunlight.

It rarely flowers when grown as a houseplant. However, when transitioned to grow outdoors in summer, it will produce orange-red flowers on softly arching stems.  

Black Tree Houseleek; Aeonium ‘Black rose’ (Aeonium arboreum atropurpureum ‘Shwarzkopf’)

Aeoniums grow in rosettes of succulent leaves ranging in color from pale to deep green, creamy white, yellow and shades of wine red to purple. Some rosettes are low-growing with densely-packed leaves, while others have looser flat rosettes of leaves growing at the tip of tall branching stems. The latter are known as Aeonium arboretum, the tree aeoniums (from the Latin ‘arboreus’ meaning tree-like).

One of the most striking tree aeoniums is the variety atropurpurium ‘Shwarzkopf’ (sometimes spelled ‘Zwartkop’) (From the Latin ‘atropurpureus’ meaning dark purple.) It bears large striking rosettes of shiny deep purple almost-black 4-inch long (10 cm) leaves. The stronger the sunlight it receives, the darker the purple. Without enough light, the color will fade to a purplish red with a pale green centre.

The watering needs of ‘Black rose’ are a little different from most other houseplants. While most houseplants are actively growing in the summer and therefore need more frequent watering, ‘Black rose’ goes dormant in the summer heat and grows mostly in spring and fall. It needs less watering during the summer months, not more.

If you live in USDA hardiness zones 9-11 and choose to plant ‘Black rose’ in your garden, be aware that in high heat conditions it will curl its leaves in towards the centre and go dormant. Keep ‘Black rose’ houseplants out of cool drafts from winter doorways or summer air conditioning vents.

Spurge (Euphorbia sp)

Euphorbias (spurge) make up their own botanical family, Euphorbiaceae.  Members of this family vary widely; some – but not all – are considered succulents, and many have features similar to cacti. They will often have “cactus” in their common name even though they aren’t true cacti.

All spurges have a sticky white latex sap that causes severe irritation to the skin and mucous membranes, and can be poisonous if ingested. If you get sap on your hands, be careful not to touch your eyes or mouth. Wash thoroughly with soap & water to remove sap. This sap is also what makes euphorbia plants toxic to people and pets.

Pencil cactus; Finger tree; Firestick plant (Euphorbia Atirucalli)

Despite its common name, this plant is not a true cactus; it just looks like one. Mature plants have thick brown stems with clusters of pencil-thick smooth bright green secondary branches growing from their tips. As a houseplant, the branches remain bright green. When grown outdoors, the branch tips turn vibrant red-orange when nighttime temperatures begin to get cooler. It produces small one-inch leaves along the branches but these leaves drop quickly.

Tiny inconspicuous flowers are produced in spring at the tips and junctions of the secondary branches. However, conditions need to be just right – including temperature, humidity and light levels – for this plant to flower indoors.

Pruning isn’t necessary, other than to remove dead branches or to enhance the plant’s overall shape. When pruning, it’s a good idea to wear gloves and a long-sleeved shirt to avoid getting the sap on your skin. 

Tanzania Zipper plant; Zebra Spurge; Thornless Spurge (Euphorbia anoplia)

The Tanzania zipper plant looks like a spineless cactus. Its shape is a leafless deeply ribbed column that looks star-shaped when viewed from the top. Columns usually grow in a clump.

The ribs are deep green with pale green to white wavy horizontal stripes. Viewed from the side, the stripes give the appearance of a closed zipper (hence one of the plant’s common names.)

Tanzania zipper plant isn’t as drought tolerant as most other succulents. You should water it when the top few inches of potting mix is dry.

Pincushion Euphorbia (Euphorbia ferox)

This slow-growing euphorbia should be treated with respect! It has sharp, extra-thick, 2-inch (5 cm) long pink thorns growing out of its barrel-shaped columns. It makes an attractive houseplant with its pink-purple thorns contrasting against grey-green columns.

One note of interest about this euphorbia is its tendency to develop  “corking” around the base. The plant tissues turn thick and dry, like a coppery brown scab on the plant. On some euphorbias corking may be caused by sudden exposure to bright sunlight, but it is also a natural habit of many euphorbias, often developing on older plants. Corking doesn’t mean the plant is diseased and no action or treatment is required.

Variegated Corn cob cactus (Euphorbia mammillaris ‘Variegata’)

Variegated corn cob is an attractive succulent cultivar with a cylindrical corn-cob looking stem made up of rows of round nodules like kernels of corn. Tiny short-lived white leaves grow from the pointy centre of each nodule. 

Variegated corn cob is slow-growing, and develops many club-like, almost horizontal, side branches along the stems. The stems are cream to frosty greenish-white dashed with emerald green. Despite its common name, it isn’t a true cactus although it does have spines. These  creamy-white spines are up to half an inch (1 cm) long and grow randomly along the stems, most densely from the younger tips. When exposed to full sun (or cool temperatures if grown outdoors in regions with mild winters), the branch tips take on a pink tinge.

Ric Rac cactus; Fishbone cactus; Zig Zag cactus (Selenicereus anthonyanus formerly Cryptocereus anthonyanus)

The Zig Zag cactus is a tropical cactus. Rather than hot arid deserts, it’s native to the tropical forests of Brazil. Like many of the tropical cacti, it is an epiphyte, growing up in the trees, in forks between the branches.

It gets its many descriptive common names from the shape of its leaves that grow along a long central spine. The dark green foliage is thick and flat, with a leathery texture, and bears small fine thorns. Zig Zag cactus adds a unique quirky interest to any indoor decor.

It is also sometimes called Orchid Cactus, after its beautiful purple-pink flower, although it needs just the right conditions to flower indoors. If it gets plenty of bright light early in the spring, and its roots are a bit pot-bound, it may produce large fragrant flowers in March or April. However, to enjoy the flowers, there’s a catch: This cactus is a night-bloomer; its flowers open only at night and last just for a day. So you may need to pull an all-nighter to enjoy them!

Zig Zag cactus is fast-growing and has a trailing growth habit, making a good choice for hanging baskets (or plant hangers) or for the top of a shelf where it can trail down the sides. You may need to trim it occasionally if it gets too long. Wear gloves when handling the plant; its thorns are hard to see but can still prick you.

Mistletoe cacti (Rhipsalis sp)

There are dozens of members of the cactus genus Rhipsalis and all are referred to with the common name Mistletoe cactus. That can make it confusing when searching for a specific variety, so be sure to make note of the Latin name of the ones you’d like to add to your plant collection.

Mistletoe cacti are slow-growing tropical epiphytes found growing in Central and South America, and a few regions in Africa and Asia. The genus name Rhipsalis is from the Greek word ‘rhips’, meaning wicker or plaited. It refers to  the trailing and interwoven growth habit of the plant stems.

Most Mistletoe cacti have cylindrical trailing segmented stems, but a select few are flat (e.g. Rhipsalis paradoxa) Some have smooth stems, while others are hairy. Colors range from bright to deep green, to blue-green or pink-red.

With their trailing habit, Mistletoe cacti are good candidates for a hanging basket in a humid bathroom or kitchen.

Some interesting varieties include:

• Red Coral Rhipsalis (Rhipsalis ramulosa) Flat reddish stems trailing to 2.5 feet (70 cm). Turns deep violet red when exposed to full sun. 
• Hairy stemmed cactus (Rhipsalis pilocarpa) Cylindrical blue-green hairy stems trailing up to 6.5 feet (2 m)
• Sausage Chain cactus (Rhipsalis clavata) Light green cylindrical segmented stems trailing to 3 feet (90 cm)
• Rhipsalis cereoides A lithophyte plant (grows attached to rocks) with triangular-shaped (rather than cylindrical) segmented stems that trail to 1-3 feet (30-90 cm)
• Clumpy Mistletoe Cactus (Rhipsalis mesembryanthoides) Strong bright green stems, bearing densely-spaced half-inch (1 cm) side branches, trailing up to 2 feet (60 cm)
• (Rhipsalis teres f. heteroclada). Light green slender cylindrical stems trail up to 2 feet (60 cm). Can develop a blush of red when exposed to bright sunlight.

Haworthia sp and Haworthiopsis sp

The plant genus Haworthia was split into two groups (genera) by the world of science in 2013 and a new genus Haworthiopsis was created. The last part of the name is from the Greek “opsis” meaning “likeness” In other words, members of the new genus Haworthiopsis have a likeness to the original genus, Haworthia.

Members of both genera grow rosettes of leaves, similar-looking to aloes (which are in the same plant family Asphodelaceae). The difference between the genera is that Haworthia have smooth leaves with thin, almost translucent, skin, while members of the genus Haworthiopsis have thicker-skinned leaves with distinctive horizontal stripes of white or red bumps (tubercles).

Haworthia and Haworthiopsis are slow-growing and tend to stay small,  under 12 inches (30 cm) tall. Mature plants will produce new offsets around the base. These offsets can be left to grow into a dense clump, or gently detached and transplanted to grow into new plants.

In their native habitat, Haworthia and Haworthiopsis grow in part shade or filtered light. They can tolerate lower light conditions than some other succulents, making them a versatile houseplant. Although they can tolerate less light, they’ll look their best when placed in bright indirect light or filtered sun (e.g. beside a window that’s covered with sheer curtains). If they get too little light, the leaves will grow long and thin (leggy) and darker varieties will lose their coloring.

Cooper’s Haworthia (Haworthia cooperi)

Cooper’s Haworthia is a rare succulent variety with translucent pale green foliage with creamy white vertical striped patterning. They take on an almost glass-like appearance, with light shining into the interior of the leaves. The 2-inch (5 cm) long leaves form mounded clusters like pointy-ended green grapes. They can be rounded or triangular, and have edges lined with fine bristly hairs. 

Zebra Haworthia, Zebra cactus (Haworthiopsis attenuata, formerly Haworthia attenuata) 

One distinctive member of the new genus is the slow-growing Haworthiopsis attenuata. It forms a small tight rosette of long and narrow thick-skinned succulent leaves. The triangular leaves form a more upright rosette than other members of the genus.

Its Latin name attenuata means “thinned or reduced” and refers to the shape of the leaves that gradually get narrower towards their pointed tips. The dark green leaves have sharply-contrasting white bumpy horizontal stripes that give the plant its common name Zebra haworthia. 

(A note about H. attenuata’s common names: Despite the name “Zebra cactus” it isn’t a true cactus. As for its common name “Zebra Haworthia” another very similar plant, Haworthiopsis fasciata, shares this common name. The only difference between the two is very subtle; H. attenuata has bumpy stripes on both upper and lower leaf surfaces, while H. faciata has smooth upper leaf surfaces without stripes. However, these smooth surfaces aren’t readily visible because the leaves grow upright with their upper surfaces facing towards the centre of a tight rosette. As houseplants they look virtually the same.)

Haworthiopsis attenuata can tolerate brief exposure to below-freezing temperatures but it isn’t considered cold tolerant. If you live in a region that gets colder than 20 F (-7 C) in winter, you’ll grow it indoors as a houseplant that can be put outside for the summer.

In its native habitat, Zebra haworthia grows in part shade under other plants or rock outcrops. As a houseplant, it prefers bright indirect light. With exposure to some direct light, the leaves will take on a maroon red coloring.

Panda Plant; Chocolate soldier plant (Kalanchoe tomentosa)

The Panda Plant is a very popular interesting succulent variety. It has pale green leaves covered in fuzzy silver-white hairs, and the leaves are rimmed with chocolate brown spots (which give the plant one of its common names).

Panda Plant is not cold hardy nor does it like extreme heat. When growing this plant indoors, avoid spots exposed to cold drafts from air conditioners or drafty winter doorways, or hot air blasts from winter heat sources.

When watering this Kalanchoe, be careful to add water to the soil and not onto the leaves. Water drops left on the leaves can cause the leaf to rot.

String bean hoya; Porcelain flower (Hoya shepherdii)

There are several varieties of Hoya, all of which are tropical succulents. They’re commonly called “wax plants” because of their thick leaves. In their native habitat, they’re epiphytes, meaning they grow on the surface of other plants – like trees – rather than in soil in the ground. They are naturally vining plants, and as houseplants they appreciate having something like a trellis or moss pole to climb on. Alternatively, they can be grown in a hanging basket to allow the vines to trail down over the sides.

Hoya roots are adapted to growing with little soil and as houseplants, they need a well-draining chunky potting mix (such as one labelled for orchids). They prefer to grow pot-bound in a container, so they don’t need frequent re-potting.

One rare and sought-after Hoya variety is Hoya shepherdii. Its thick slightly-curled leaves are longer and narrower than other Hoyas, and earn it the common name String Bean Hoya. In addition to its unique foliage, it’s known for its beautiful fragrant flowers, although the plant needs to be at least 5 years old before it flowers. 

Conditions need to be just right for it to flower as a houseplant. It needs bright indirect light, and like other hoyas, prefers to be slightly pot-bound. Using a pot that gives the roots too much space can inhibit flowering.

The potting mix needs to be light and chunky for excellent drainage. Over-watering can affect its ability to bloom. Keeping the soil on the drier side and exposing the plant to a couple of hours of morning sun will encourage flowering.

When String bean hoya does bloom, it produces tight clusters of small star-shaped flowers. The flowers are white or light pink with maroon centres and have a rich perfume-like fragrance.

Flowers grow from flowering spurs (called peduncles) at the leaf node (where leaf attaches to the main stem). Flowers grow from the same spur from year to year. If you want to see flowers again the following year, don’t dead-head the spent flowers or you risk removing the flowering structure.  Instead, allow the flowers to drop off naturally.

Living stones; pebble plant; split rock plant (Lithops spp)

Living stones are small yet interesting – some may say quirky-looking – plants. Their shape and coloring have evolved to mimic the pebbles they grow amongst in their native habitats. As a result, they’re perfectly camouflaged to protect them from grazing animals.

Living stones come in a wide range of colors from pale grey to green-grey to purple and brown, often in a combination of colors and patterns. Collecting Living Stones can become a hobby in itself.

Each plant is almost stemless, and made up of a pair of thick fleshy leaves that grow close – in some cases fused – together. These form a short flat-topped mound with a slit down the middle. Depending on the species, the slit may run across the whole mound or the leaves may be almost completely fused with just a narrow slit in the centre. This can give them a rather comical look (two fleshy mounds with a crack down the middle?)

One Living stone variety, Conophytum pageae, has grey-green leaves that grow almost fused together, with a small slit in the centre, surrounded by slightly raised purple-red edges. This earns the plant its common name, Lips plant. 

Living stones are very slow growing, and can be tricky to maintain. In fact, they need minimal maintenance. They require very little water, going several months between waterings. They should only be watered in spring and fall, their active growing seasons. They go dormant in summer and winter and require no watering. They most often suffer from too much attention instead of not enough.

The leaves will show slight wrinkling on the sides, which is normal. When the flat tops start wrinkling, then it’s time to give the plant some water. Over-watering, or watering during their dormant season, will cause living stones to go mushy and die. 

Living stones have a long tap root, so they need a container about 6 inches (15 cm) deep.

They will flower when the plant is at least 3-5 years old. Flowers emerge from the centre, between the two leaves, and last only a few days. Once they’ve flowered, the plant goes dormant and should not be watered. New sets of leaves will appear from the slit between the old set, at which point the plant should be watered again.

Air plants (Tillandsia sp) [This topic might warrant its own article] 

Air plants are unique among houseplants. Instead of growing in soil, they grow roots to cling onto tree trunks or branches. Some even grow on cacti in the desert. They can also cling onto rocks or even buildings.

What makes them unique – besides their appearance – is that they don’t take up nutrients or moisture through their roots. Instead, they absorb what they need from the air – hence their common name – through specialized hairy growths (called trichomes) on their leaves. These trichomes also reduce moisture loss from the leaves, reflect sunlight, and keep the plants from overheating.

Air plants grow in a rosette of long stiff leaves that form a wide bulb at the base and get thinner towards the tips that are often curly. Many of them look like silvery squid with lots of tentacles, while others are flatter and fan-shaped.

Air plants are native to forests, mountains and desert regions of tropical and subtropical zones of North and South America. In the US, they can be found growing in many states, including Florida, California, Texas and Georgia. In fact, the familiar Spanish moss seen growing from tree branches across the Southern US, Mexico and South America is a type of air plant, Tillandsia usneoides.

There are two groups of air plants: Those that are native to humid or semi-humid forest habitats (the “Mesic” group), and those from drier alpine and desert-like climates (the “xeric” group). It’s important to know which variety you have so you know how to maintain them.

Mesic air plants like medium humidity, need more frequent watering and prefer bright indirect sunlight or filtered light (e.g. through sheer curtains). They have smooth deep green leaves with few visible trichomes. 

Xeric air plants come from drier conditions, are much more drought tolerant and can handle some direct sun. Their leaves are thickly covered with trichomes, giving the foliage a silvery green, often fuzzy, appearance. 

To water an air plant, use a spray bottle set on “mist” to thoroughly wet all the foliage. You can also float your air plant in a bowl of room-temperature water for several hours. How often they’ll need watering will depend on the growing conditions; warm, dry indoor air will dry out air plants more quickly than conditions of higher humidity. Slightly curled leaves (along the length of the leaf, not the leaf tips) indicate the plant needs watering, about every 7-10 days. Brown leaf tips are a sign the plant isn’t getting watered often enough.

Since air plants absorb nutrients along with moisture through their leaves, they like to be watered with “dirty” water such as from a rain barrel, lake or pond, or even a freshwater aquarium. These sources provide a natural source of nutrients. Tap water should be left to sit for 24 hours to allow any chlorine or other additives to evaporate.

When watering consistently with tap water, air plants should be fertilized every 4-6 weeks during the spring and summer. Add a balanced houseplant fertilizer (or a bromeliad fertilizer) diluted to a quarter recommended strength to the water when soaking or misting.

Getting your Tillandsia to bloom can be a bit challenging. The conditions, including light, temperature and humidity, need to be just right. With proper attention to these details, air plants will reward you with outstanding long-lasting flowers in shades of red, pink, purple, orange or yellow.

They flower only once in their lifetime. After they flower, they produce offsets (or “pups”) at the base of the parent plant (and the parent plant dies away.) Once these offsets are about 1 third the size of the parent plant, they can be gently detached to grow as separate plants. They can be left in place to grow as a clump.

Carrion flower; Starfish plant (Orbea variegata, formerly Stapelia variegata)

The Carrion Flower is true to its name. The smell of this succulent’s blooms has been described as disagreeable, disgusting and even offensive! All Stapelias have spectacular-looking chunky star-shaped flowers but most people can’t get past the smell of the Carrion Flower (which is like fish or rotten meat). If you like a bit of adventure, try the Carrion flower!

Despite their smell, the flowers are still the real stars (pun-intended) of this plant. One to three individual flowers grow off stalks that emerge from the base of the plant stems. Each flower has its own 2-inch stem that arches out from the main stalk so that each open flower lies flat on the ground. The fleshy star-shaped flowers are about 2 inches (5 cm) across, and look like chubby starfish (hence the plant’s other common name). Flower color is a greenish-yellow with chocolaty-purple patterning and maroon-brown spots. 

The Carrion Flower can take several years to bloom but even when not in flower, the plant has an attractive unique appearance. The 3-inch (8 cm) thick square stems are grayish-green and grow up to 10 inches (25 cm) long. In full sun, the stems take on a mottled purple appearance. Small scale-like spines grow along each ridged corner giving the stems a toothy appearance.

The plant’s stems are sprawling rather than upright, and develop offsets that eventually form a dense mat up to 2 feet (60cm) wide. The trailing habit makes it a great choice for a hanging basket or shallow containered houseplant. 

String-of-pearls (Senecio rowleyanus)

The name String-of-pearls perfectly describes this sought-after succulent. Its leaves look like small ¼ inch green peas with pointed tips, growing alternately along thin stems. In its native habitat, it grows as a ground cover trailing along the soil surface.

String-of-pearls can be grown in a hanging basket so the stems hang down over the sides. Or it can be grown in a wide shallow dish to allow it to trail along the soil as a ground cover plant.

String-of-pearls has a shallow root system. So, rather than waiting for all  the soil to dry completely between waterings, you’ll only need to wait until the top few inches – where the roots grow – have dried out. Then give the plant a deep thorough watering. If you notice the shape of the pearls has changed from round like a pea to more oval like a lemon, then it’s time to water before the pearls start to wrinkle.

String-of-pearls likes a few hours of direct sun when grown indoors. An east-facing window that gets morning sun is a good spot. To keep the growth lush all along the stems, be sure the sunlight is hitting the crown of the plant, not just the long trailing stems.

Donkey’s tail (Sedum morganianum) 

There are two very similar forms of this popular sedum available on the market. The first is the natural species form, Sedum morganianum (Donkey’s tail), with short pointy leaves. The other is a cultivar, Sedum morganianum ‘Burrito’ (Burro’s tail), with short rounded leaves. Other than the leaf shape, the plants are identical.

Both varieties have trailing stems bearing closely-spaced rows of blue-green leaves. The stems grow on average to 24 inches (60 cm) long but can sometimes reach as long as 4 feet (120 cm). Donkey’s tail is often grown in hanging baskets to highlight its trailing habit.

The leaves on Donkey’s tail are very sensitive and tend to fall off easily when the plant is moved or disturbed. So, it’s best to find the perfect spot for it and then leave the plant alone except to add water.

Cylindrical Snake plant; African spear (Sansevieria cylindrica) 

The Cylindrical Snake plant has round vertical spear-like leaves. They grow to 1.5 inches (4cm) thick and are smooth and green with pale wavy horizontal stripes. Each leaf emerges from the soil, with several leaves growing in an upright bunch. Slow-growing up to 6 feet (180 cm) tall, its vertical habit lends it to a formal architectural appearance for a modern minimalist decor.

When the leaves are young and more pliant, they can be braided for an interesting decorative effect.

Cylindrical snake plant prefers bright indirect light but is adaptable to lower light conditions. With less light its growth will be slowed.

Interesting Cold Hardy (Outdoor) Varieties

The following list includes some interesting-looking cold hardy succulent varieties as well as others that are more unusual for planting in outdoor gardens. 

Whether or not you can grow these varieties in your garden will depend on your growing zone. If your winter temperatures get too cold, you can grow outdoor succulents in containers and bring them indoors over the winter. You will need to gradually transition them back to outdoor conditions the following summer [link to Article #6?]

Stonecrop (Sedums sp)

There are many varieties of outdoor sedums that are hardy well below freezing. They prefer full sun, are drought tolerant once established and tolerate varying soil conditions as long as they have good drainage. It is especially important they don’t sit in wet soil over the winter.

Sedums don’t like – or need – overly-rich soil. Average urban garden soil will generally provide adequate nutrients without the need for added fertilizers every year. Soil that is too rich in nutrients will result in weak leggy growth.

Outdoor sedums have three growth habits:

Creeping varieties that form a dense groundcover, often spreading several feet

Tall varieties that have an upright growth habit and can grow up to 2 feet (60 cm) tall and wide

Trailing varieties that form looser mats than creeping varieties and are good for spilling over rock walls or planted in hanging baskets. 

Sedums have foliage ranging in color from deep green, blue-green, lime green, silvery grey, creamy yellow to shades of pink, purple and red. They produce flat clusters of star-shaped flowers of red, pink, white or yellow at varying times of year.

Sedums make beautiful low maintenance additions to the outdoor landscape. They’re perfect for rock gardens, bordering gravel pathways, rock wall crevices, or blended in amongst other drought-tolerant perennials.

In milder winter regions sedums are evergreen. Many varieties take on vibrant winter coloration to their foliage. In colder climates, sedum top growth dies back for the winter and returns again in the spring.

The following sedums make interesting and attractive additions to the outdoor garden with their foliage and flowers.

Mossy stonecrop; Least stonecrop (Sedum lydium)

Mossy stonecrop is a classic creeping groundcover whose stems root where they touch the ground. It is a short ground-hugging plant with succulent quarter-inch (60 mm) long needle-like leaves. In summer, the foliage is a brilliant green. Its evergreen leaves turn bronzy-red in fall and winter. Extended periods of summer drought may also cause the foliage to take on red tinges.

In early summer, mossy stonecrop produces tight clusters of soft white star-shaped flowers on short leafy stems. The flowers are long-lasting and attract bees and butterflies.

In its native habitat of central Turkey, it grows in damp mossy places in the mountains. Despite that, it is a hardy drought-tolerant garden plant.

October Daphne stonecrop (Sedum sieboldii)

October Daphne stonecrop is a classic groundcover succulent with small round blue-green leaves that clasp the stem in groups of three. It is prized for its foliage that emerges blue-green in spring, takes on deep pink edges in the summer heat, then turns full bronzy-red with the arrival of cool temperatures of fall.

Clusters of small bright pink flowers appear in late summer, attracting bees and butterflies. It’s a perfect choice for the rock garden, between stepping stones or in the crevices of dry walls.

Tricolor stonecrop (Sedum spurium ‘Tricolor’)

Tricolor stonecrop is a creeping mat-forming variety that stays under 6 inches (15 cm) tall. The elongated spoon-shaped leaves are blue-green down the centre with white edges tinged with pink. Tolerant of foot traffic, this sedum is a good choice to plant between stepping stones or along pathways. Clusters of pinkish-red star-shaped flowers are borne on reddish stems from late spring to mid-summer.

Purple Emperor Stonecrop; Autumn stonecrop (Sedum telephium ‘Purple Emperor’)

Purple emperor sedum is a long-lived drought-tolerant perennial. It’s very cold hardy and dies back for the winter. It has a tall upright form that adds color to the garden with its deep purple stems and foliage. It produces attractive pink flowers in mid to late summer and continues flowering until first frost. They make an excellent long-lasting cut flower and are a much-loved late season food source for bees and butterflies.

Hens ‘n chicks; Houseleeks (Sempervivum sp)

Hens and Chicks are native to cool, mountainous regions, and are cold tolerant. They can grow outdoors in USDA zones 4-10, where cold dry conditions bring out their interesting colorations. They get their common name from their growth habit; their leaves grow in dense rosettes (hens) that, when mature, produce small offsets (chicks) around their base. Over time, they form dense mats of multiple rosettes.

Mature rosettes produce clusters of small towers at the tips of bare stems that grow up several inches above the rosettes. Individual rosettes die after flowering, leaving behind a space to be filled by the new offsets.

There are several varieties of Hens ‘n Chicks available commercially,  ranging in size and color, including shades of green, grey, pink, red, orange, purple and bronze-brown. Some are multi-colored and the cobweb Hens n’ Chicks have a covering of fine hairs that look like spiderwebs.

All Sempervivums prefer full sun and need well-draining gritty soil that doesn’t sit wet in winter. They’re drought-tolerant and don’t need a lot of fertilizing. They make a great choice for rock gardens or gravelly sites.

The following are some of the more unusual and interesting Sempervivum varieties.

Sempervivum ‘Gold Nugget’

‘Gold Nugget’  has intense colors that change with the seasons. In spring and fall, the dense clusters of leaves are a bright yellowy-green with fiery orange tips like bright flames. In summer, the leaves transition to entirely electric lime-green. In winter, the foliage is crimson red with golden edges.

It is a vigorous grower, quickly producing many offsets around the base. In summer, a flower stalk grows from the centre of the mature rosette and bears a cluster of small star-shaped pink flowers.

Arctic White cobweb Hens and chicks (Sempervivum arachnoideum ‘Arctic White’) 

‘Arctic White’ is an eye-catcher for the outdoor garden or indoor containers. Each of its grey-green rosettes is densely wrapped in silvery-white hairs like ghostly spiderwebs. It’s a low-growing variety whose small rosettes grow in dense silvery mats up to 6 inches (15 cm) wide. Each rosette is only  half an inch (1.5 cm) to 1.5 inches (4 cm) across. ‘Arctic white’ provides a strong contrast to offset other colored succulents in the garden or plant them en masse for a stand out garden feature.

‘Arctic white’ produces clusters of small pink flowers from May through July.

Sempervivum ‘Oddity’

‘Oddity’ is a rare succulent variety that lives up to its name! Its lime green leaves, tipped with purple-red, curl in on themselves forming a quirky clump of tubes. Each rosette grows 3-4 inches (7.5 – 10 cm) wide. The unusual leaf shape and coloring make it a collector’s favorite. 

‘Oddity’ is a hybrid developed in the US, grown for its interesting foliage, as it’s an infrequent bloomer. It has been known to occasionally revert back to normal-looking flat Sempervivum leaves.

Sempervivum ‘Cosmic candy’

‘Cosmic candy’ is a rare show-stopper cobweb variety. It forms 3-4 inch (7.5 – 10 cm) wide loose rosettes of rich burgundy red leaves,with a green centre topped with silvery cobweb hairs. The long pointed leaves are tipped with tufts of fine hairs, with more hairs along the leaf edges.

Flower stalks grow up to 8 inches (20 cm) above the rosettes and bear spikes of pink star-shaped flowers in mid-summer.

Prickly pear cactus (Opuntia sp)

There are several different species of Prickly Pear cactus (Opuntia). They are the most cold tolerant of the lowland cacti, with species native to many parts of North America, from Northern Canada, south into the US and throughout much of Mexico. (Fun fact: The Prickly Pear – no particular species – is the designated state plant of Texas, where more than one species can be found.)

Prickly pear cacti don’t have true leaves. Instead, they have modified fleshy stems made up of several segments or “pads”. These gray-green flat oval pads are covered in spines, some large and easy-to-spot, others in small clusters but no less prickly.

Prickly pears are named for the sweet fruits they produce. These can be used for juice or making jams and jellies. The pads are also edible, and are used in Native American and Mexican traditional cuisines.   

Prickly pear cactus planted in the garden might not bloom for the first few years after planting. To encourage good growth, they should be planted in the sunniest spot possible and fertilized once a month in spring and summer with a 5-10-10 fertilizer. 

Eastern Prickly Pear; Devil’s Tongue (Opuntia humifusa)

The Eastern prickly pear is the only cactus native to Eastern regions of the US, with a very narrow range in Canada. In the US it’s found from Massachusetts to Florida in the east and from South Dakota to eastern Texas in the west. Its range in Canada is limited to a small area in the very southwest of Ontario, at Point Pelee and on Pelee Island in Lake Erie, where it grows in open and semi-open dry sandy environments.

The oval pads of Eastern Prickly pear form segmented branches that grow into wide mounds up to 18 inches (45 cm) high. Pads are covered in clusters of tiny reddish-brown stiff barbed hairs that are very irritating if they penetrate the skin. Pale yellow papery flowers are borne from the pad tips at the end of the branches. Flowers are followed by small spine-covered edible fruit.

Plains Prickly Pear (Opuntia polyacantha)

Plains Prickly Pear is a cactus native to North America. It can be found in the central and Western US, Western Canadian provinces as far north as the Yukon Territory and northern Mexico. The plants grow in low mounds up to several feet wide. 

Plains prickly pear blooms on the pads at the tip of each branch, bearing golden yellow flowers that become more reddish as they age. Flowers are followed by small red-purple spine-covered berries.

Fragile Prickly Pear; Shattering Cactus (Opuntia fragilis)

Fragile Prickly Pear is native to much of western North America. It is found further north than any other cactus species in the world, from northern Alberta, 

The egg-shaped fleshy pads are a dull dark green. They’re up to 2 inches (5 cm) long and ½ to 1 inch (1 – 2.5 cm) wide with a waxy surface. The pads have multiple clusters of 3-8 spines up to 1 inch (2.5 cm) long growing across the surface.

Fragile prickly pear is a low-growing sprawling plant, forming mats up to 2 feet (60 cm) across. The pads detach from the rest of the plant very easily (hence the plant’s common names). A word of caution: Just a slight touch of the plant and it will sink its spines painfully into your skin and detach the pad from the rest of the plant! 

In summer, Fragile Prickly Pear produces showy yellow flowers 1.5 – 2 inches (4 – 5 cm) across. It produces fewer flowers than other Prickly pear species, and some plants fail to flower every year.

Turkish stonecrop (Rosularia platyphylla) 

Turkish stonecrop resembles Hens and Chicks (Sempervivum) in shape and growth habit. Its Latin name “rosularia” means “with rosettes.” It has succulent spoon-shaped light-green leaves that grow into rosettes up to 4 inches (10 cm) across. The leaf margins take on a red tinge in cooler weather or when exposed to bright direct sunlight. It’s slow-growing and eventually grows offsets to form clumps about 8 inches (20 cm) wide.

Turkish stonecrop bears tight clusters of white or pale-pink star-shaped flowers on 6-inch (15 cm) tall flower stalks in summer.

Ice plant (Delosperma cooperi)

Ice plant has short and narrow glossy green succulent leaves. It is a vigorous grower and once established it quickly forms large dense mats of greenery. There are many cultivars available, with daisy-like flowers in colors including pink, yellow, orange, red, white, purple and  bicolor. They bloom continuously from late spring through to fall, adding rich color to rock gardens or open gravelly spaces where little else will grow.

Ice plants are native to areas of South Africa that get rain in summer, so as a garden plant they require more regular watering than other succulents. In regions that get winter rain or snow, protect the plants with row cover or straw, and be sure they’re planted in spots where the soil drains well and doesn’t stay wet in winter. (The wetter the soil in winter, the less cold hardy a plant will be.)

Ice plants are perennials in zones with mild enough winters and where the soil has very good drainage. In colder regions, ice plants are often grown as an annual because they flower all summer. They’re a good choice for summer hanging baskets and will grow quickly to trail down over the sides.

Lewisia, Cliff Maids (Lewesia cotyledon or Siskiou lewisia)

Lewisia grows in flattened rosettes of long dark green spoon-shaped  leaves. It is sometimes called Cliff Maids because it grows on rocky cliffs at higher elevations in its native habitat from Oregon to California.  In early spring or summer, it sends out 6-inch (15 cm) long flower stalks from around the base of the rosette, bearing loose clusters of multi-petalled tube-shaped flowers. The flowers are about 1 inch (2.5 cm) across, in colors ranging from pale pink to salmon orange, yellow, magenta and white. Flowers are often shaded with streaks in multiple colors.

Lewisia is easy to grow, likes full sun and moderately fertile, well-draining soil. Like many other succulents, Lewisia is drought tolerant and needs protection from winter wet conditions. With its strong root system and deep tap root for growing on cliff sides, Lewisia is a good choice for planted rock walls.