For the gardener who has only a few odd minutes to spare for plant cultivation, growing cactuses and succulents as houseplants will give you a great amount of satisfaction. Cactus and succulents offer untold opportunities for growing in your home. Those who live in city apartments and who only have small rooms and shelves to grow plants on can easily accommodate two or three dozen cactuses where there would hardly be space for one good sized Boston fern or a couple starved geraniums.
Unlike most other houseplants, cactuses do not greatly resent it if you don’t water them on a regular cycle. They have no tender foliage to get damaged or that will fall off if conditions become unfavorable. They require less attention as far as repotting into larger containers as well. Their slow growth rate is another advantage for the gardener, as a large assortment of plants can be kept in the same small area for a number of years without becoming overcrowded.
Small succulents and cactuses are never in the way, and can be shifted about easily as necessity demands. They will also survive accidents and some degree of poor treatment. Cats and dogs can knock down your cactus, and they’ll live through it! Although, you should obviously avoid this kind of care. Of course, cactuses and succulents will give amazing returns with good treatment.
Ideal Growing Conditions
The ideal place for cactuses in winter is a rather damp greenhouse, but they will thrive in the window garden, so long as they never get frozen. Try to keep the night temperatures about 50 degrees. The drying of the soils under ordinary house conditions makes watering in winter a necessity. Placing them out in a greenhouse during the winter makes watering less necessary.
The window gardener must remember that although they are desert plants, they do not naturally grow in small pots which are sometimes exposed to warm, dry air.
The growth of the plants is improved if they are placed outdoors when all danger of frost is past in the early spring. Some gardeners like to remove the plants from their pots and place them in their garden. However, it is best to keep the plant in its container and to place the plant and pot together in the soil. This will minimize damage to the roots and make it easier to move the plant back into the house in the winter. When moving them outdoors in the summer, place them in a well-drained border, fully exposed to the sun, and with free circulation of air.
Soils and Pots for Cactus Plants and Succulents
It does not matter much what sort of soil is used for cactus and succulents so long as it is a well-draining soil. That is the essential part in growing these kinds of plants. One successful grower uses equal parts sandy loam, sand, and coal ashes, and advises the improvement of a clay soil by adding to it a little air-slacked lime. Another equally successful mix is equal parts fibrous loam and clean gravel, with a little fine sand mixed in.
The succulent plants other than cactuses can be grown in much richer soil, but great care must be exercised in not overwatering, which may cause stems and roots to rot. Seedling succulents may be grown in pots—one to a pot—or in flats with a large number in each one. It is handy to have the plants in large pots. Even the smallest seedlings need drainage. A good rule to follow is to fill one-quarter to one-third of the pot with coarse drainage, like gravel, over which you put a little sphagnum moss to keep the soil from sifting down into the gravel.
When potting up a cactus select a pot just a little larger than the body of the plant. Many people crowd the plant into as small a pot as possible, but I believe this is not a good practice, because the plant needs some space to grow, and if the pot is small it is also very difficult to water properly. When potting, put the coarsest part of the soil next to the drainage, with the finer part above it and around the plant so that the plant is only a very little below the surface of the soil.
After potting, give a little water to settle the soil. Don’t give more water until the plant begins to grow. Lightly water the plant with a syringe on bright, sunny days. If the potting is done in early summer and the plants are placed outdoors, the water which they receive will be sufficient until growth begins.
Too much water or too rich and heavy soil may cause rotting of the plant at the soil line. This is the most common cause of plant loss among novice gardeners. This problem can only be avoided by watching the plants and soil closely and watering only when the plant becomes dry. When you water, give enough to thoroughly dampen all soil in the pot.
A properly potted cactus or succulent plant will not need shifting for several years, and will do all the better for not having the roots disturbed. If the soil becomes water-logged or starts to grow moss, repot the plant at once. Mealy bugs sometimes attach to the roots of succulents and cactus. As soon as this problem is detected, shake the soil from the roots and thoroughly wash them in clean water, repotting the plant with a clean pot and new, clean soil.
Cactuses are not helped much by fertilizers and high quantities of organic material in the soil. The only exceptions to this rule are older specimens of night-blooming cereus, and the crab cactus (Epiphyllum). Occasional watering with compost tea will benefit these plants.
Growing Succulents and Cactuses from Seeds and Cuttings
The only way to get flawless specimens of cactus and succulents is to grow the plants yourself from seed. The process is generally quite simple. Specimens collected in the wild can be damaged, and thus are not usually as robust as plants grown from seed. You can begin your cactus from seed at any time of year with the confidence of producing plants of a good size in twelve months or so. This is especially true of such genera as Cereus and Opuntia.
To grow cactuses from seed sow the seeds in a well-drained seed soil, and handle them like any other seed. After germination give less water than for other kinds of seedlings or the young plants with burst. That is to say, the skin will open, resulting in a permanent scar.
Making a cutting of cactus is the easiest thing in the world. Just cut or break off a piece of the plant and you’re done! Since the tissues are so watery, the cut surface must be callused before the cutting is planted. Lay in on a shelf in a sunny location where there is good circulation. The cut will callus within a few days.
Such succulents as the aloes, haworthias, apicras, and gasterias may also grow from suckers as well as from seeds and cuttings.
Late May and June is best for starting the cuttings because the wounds will heal quickly and well.
When collecting a plant from a friend’s yard or garden, they may be badly damaged when removed. Make a clean cut with a sharp knife (always a sharp, sterilized knife). If the base of the plant is hard and woody, remove that part also, because the roots will start only from the fresh growing parts of the plant. Cut back to the soft, watery tissue, and expose to the sun until the wound has callused. Any diseased or decayed portion of the plants must be cut out. If the disease continues to spread, cut out the area again and cauterize with a hot iron.
Recommended Varieties of Cactus and Succulents for the Home
If you’re growing cacti as houseplants, we can generally group them into these different classes:
In the first class are the Prickly Pear (Indian figs) and some species of the genus Cereus, but I wouldn’t recommend some of these because they are prone to becoming top heavy. However, there are some appropriate tall cacti for the home.
Only two of the tall growing kinds of cactuses need to be included in the novice gardener’s collection. The Opuntia have flat, round or club-shaped stems, but they are usually flat, and the joints either round or oblong in shape. The rather large flowers are borne singly on the upper edges of the young growth and are quite showy. They are usually yellow, but you can also find them in various shades of red. One of the best of these kinds of cactus is O. microdasys which has flowers two inches across and a greenish yellow in color.
A very interesting cactus, but more difficult to grow, is the dwarf prickly pear (O. crinifera, also known as O. senilis). Instead of spines it has long, silky white hairs. It should be grown under a bell glass if you want the hairs to remain clean. It never attains a height of more than about three feet.
In Mexico the organ cactus (Cereus marginatus) is used for hedges or fences. It is distinct in appearance from others of its genus. The stem is seldom over three inches in diameter, with five or six very obtuse ridges, each of which has a row of short, black spines, which grow in bunches of seven to nine. This is a good cactus for growing in the house as well.
The opuntia is the most disagreeable of all cactuses to handle because of the very small brown spines which grow in bunches all over the stems and fruits. These spines are barbed, something like a fish hook, so that when they are in the skin it is very difficult to remove them.
Because of these troublesome spines in the ordinary forms the so-called “spineless cactus” is sometimes grown in the home as a houseplant. These plants are a good option for many gardeners.
Attractive Flowering Cactus
With very few exceptions cactuses are not grown for their flowers. However, when cactus flowers do appear they are every bit as gorgeous as many of the better know flowering houseplants. Indeed, with their intensely glowing ruby and purple shades, they can rival even the most showy of the orchids.
The flowers are also very large in comparison with other plants, so it is not unusual to see a little cactus three or four inches high in a small pot with two of three flowers the same size as the parent stock!
One of the most common flowering cacti for the window garden is the crab cactus (Epiphyllum truncatum) because it gives such a wealth of bright flowers. The young stems are flat, resembling the claws of a crab, but they become round and woody with age. During the winter each tip produces a pair of brilliant ruby-red flowers. They can also be violet-red depending on the variety. In Europe there are many named varieties of this cactus. It is a great cactus for hanging baskets. It flowers mostly in the winter. In its native country it is an epiphyte, but it can be grown successfully on its own roots in the soil. Another way to grow it is to have a plant grafted on Pereskia. Try growing your crab cactus in a soil made of equal parts fibrous loam, leaf-mould, and sand, with some finely broken up charcoal or broken up bricks for drainage.
Another beautiful red flowering plant which blooms in summer is the orchid cactus (Phyllocactus Ackermannii). Its big flowers grow up to six inches in diameter and are similar to those of the night-blooming cereus. They are scarlet-red outside and carmine-red inside. It has flat stems and grows only about three feet high. You should grow it in a similar way as the night-blooming cereus.
The Night-Blooming Cereus
The most popular of the vine-like cactuses are actually several quite distinct plants. They are all commonly known as “night-blooming cereus.” Two genera are confused under this name—Cereus and Phyllocactus. They make long, straggly stems, which may be trained up along the window cases or over trellises.
The stems of Cereus have three to six angles, while Phyllocactus stems are flat, the ends looking like long, fleshy oak leaves. All the cereus and night-blooming phyllocactus have large white flowers. They expand just after sundown, and remain open until the sun shines upon them the following morning, when they collapse.
These plants need a richer soil than ordinary cactus. Give them a fibrous compost, and mix some gravel with it to ensure good drainage.
Dwarf Cactus and Succulents
Often regarded purely as window garden plants, the dwarf species of cactus and succulents, which grow to about a foot or less, are very desirable as houseplants. They possess a great variety of unusual forms, and some are actually quite spiny.
One of the most peculiarly shaped is the “bishop’s cap” (Astrophytum myriostigma). The outline of this cactus is of a flattened globe, and at the most this plant grows to about only five inches in diameter. It has five or six very prominent ribs, on the edges of which the pale yellow flowers are borne.
The surface of the plant is more or less covered with a white scale-like growth which is actually clusters of minute spines. This plant seems particularly prone to rot at the surface of the soil, though. To avoid this you can graft it on a cereus.
Of the same general kind of plant is the sea-urchin cactus (Echinopsis). If it were not for the ridges these plants would look like gourds standing on their small ends. They sometimes reach a diameter of twelve inches, but if grown in the home they rarely exceed half that size. The stem has anywhere from a dozen to eighteen sharp ridges. The flowers are about six inches long, trumpet-shaped, and are either red, pink, or white. The two most commonly grown species are E. multiplex, with rose-red flowers that bloom only occasionally, and E. eyriesii, which has white flowers produced regularly.
One of the most curious dwarf cacti is the living rock cactus (Anhalonium engelmannii). This plant is also called “Dry Whiskey” because a very strong, intoxicating drink is made from crushing the plant and adding a little water.
Among the very smallest dwarf cactuses are the mammillarias, which seldom grow over six inches high. These get their name because they are covered with tubercles instead of ridges. These are usually set in rows which twist spirally around the plants. On the end of each tubercle is a cluster of small spines. The flowers are small and tubular, yellow, red, carmine, or purple. In a month or two after the flowers have disappeared a little red fruit appears, and is as pretty as the flower.
Mammillaria bicolor is a very handsome species, with white spines which lie flat on the stem. With M. plumosa and M. lasiacantha the spines are like fine white hairs. When grown under tumblers to keep the dust from collecting and soiling the hairs, the plants look like clumps of cotton.
The “old man cactus” (Pilocereus senilis) is another one of those curious fuzzy cactuses needing protection from dust. The hairs are from two to five inches long. The flowers, which are seldom produced in cultivation, are four inches long, and red. In a pot this plant rarely exceeds a foot in height, although it becomes a veritable tree in its native haunts.
Other Cactus and Succulent Plant Varieties
The Century Plant
Probably one of the most talked about among succulents for the home is the so-called century plant (Agave americana). It gets its name from the idea that it blooms once every century, which is not really true. It seldom does bloom in cultivation, but that is because of insufficient pot room which cramps the roots and supplies only a small amount of nutrients to the plant itself. The flowers are borne in clusters at the tops of a tall, stout stem and have a weird candelabra-like effect.
Under favorable conditions the century plant flowers about every twenty years. To accomplish this, an abundance of plant food and water is needed. Although this and other agaves come from arid regions of the Americas, they will promptly respond to good treatment in most homes.
The century plant is a good pick for the novice gardener. If you grow it indoors for part of the year, you can set it in the lawn during the summer. Avoid exposing the agave to frosts, though. If stored in a cool, well-lit place during the winter, it will rarely need water. Small agave plants can be grown all winter in the living room, and when warm weather comes they may be used for porch decoration.
The century plants are well adapted as houseplants because of their symmetrical growth pattern. A large century plant will have forty or fifty fleshy leaves, each about three or four feet long and three to four inches across. The leaves gradually taper to a point that is tipped with a very sharp spine. The edges of the leaves also often have a few short spines. They form a large rosette which sits on the ground. The leaves typically are of a light green color but there are several other varieties known as picta, variegata and recurvata. Some of the varieties have a more or less broad yellowy stripe down through the center of the leaf, while in others the leaves are edged with yellow.
Should you be so fortunate as to have a plant flower, do not be surprised that it dies as soon as the seeds mature. This is the plant’s nature. However, the plant may be perpetuated by the numerous suckers which can be found around the base of the original plant.
There are about one hundred and fifty different species of agave out there, varying in size and shape. There is really little difference between them, so unless you’re a botanist you don’t really need to worry about picking a specific species to grow in your home.
The only exception is the Queen Victoria Century Plant (Agave Victoria-regina). The leaves of this plant are short and thick—so thick that sometimes they appear to be three-sided with three more or less well-defined edges having white filaments. The ends of the leaves are blunt but tipped with a short black spine. The leaves are set so close together and so regularly that they form a hemispherical mass. Where the room is limited this is the best plant to grow. The Dirt Doctor Howard Garrett has an interesting site about the Agave Victoria-regina.
Give century plants sandy soil and pot them firmly. If they are planted outdoors during the summer, be sure they are in sufficiently large pots so that when taken up in the fall they will not need repotting.
The University of Arizona has a great website about the century plant.
Next to century plants I believe that the aloes are the most interesting for growing as houseplants. Although there are a large number of species, only a few are in general cultivation, the most common of which is the Barbardoes aloe (Aloe vera). Strange as it may seem it belongs to the same family as our beautiful Easter lily.
The light green leaves are very thick and fleshy and taper gradually to a point which is not tipped with a spine. At a distance the edges look as if they have spines, but the leaves are actually quite soft, pliable and fleshy.
In the late winter months a flower stem about one and a half or two feet long is produced which bears at its top a conical-shaped cluster of yellow flowers. The flower stem reminds you of the flower cluster of the red-hot poker plant (Kniphofia), a close relative. The individual flowers are about one and one-quarter inches long, yellow, and crowded closely together. A single flower lasts only a day or two, but the lower ones open first while the buds of the upper ones are still forming so that one plant will be in flower a while if you care for it properly. There is also an aloe with a red flower, A. sucotrina.
These aloes have one bad habit: when they begin to get of any size they become top-heavy. To overcome this, stake them for several years. If the plant becomes too big for the window garden and yet you do not wish to dispose of it, use it outdoors during the summer and store it during the winter as suggested for century plants. Under this treatment, the plant will probably not flower, though.
The aloes prefer a richer soil than most of the succulents. I have seen them thriving when grown in nothing but garden loam. However, I prefer to give them a soil made up of about three parts sandy loam, and one part gravel. You can also add a little well-decayed compost to give the plants some extra nutrients. If you don’t know much about composting, please see this excellent compost guide.
The University of Maryland has an interesting website on growing aloe for medicinal purposes.
Little Pickles: A Good Basket Plant
The best succulent for a hanging basket is “little pickles” (Othonna capensis). Its leaves are shaped like cucumber pickles, but are only an inch or less long. The flowers are yellow, one-half to three quarters of an inch across and look like dandelion flowers. They only open in the sun but during various season of the year. Each shoot has a flower stalk on the end of it. Little pickles may be reproduced easily by planting pieces of the stem. It does best when given a fairly rich soil, but be careful not to over water it.
The Old-Fashioned “Air Plant”
If you want something interesting to show your friends, grow the so-called “air plant” (Bryophyllum calycinum). The plant itself has little decorative value, and it blooms only about ounce a year. The flowers are reddish green with white spots, and are about two inches long, forming in clusters. The curious thing about this plant is that it will produce a new plant at each indentation. I have seen leaves pinned to a wall or window casing in the house produce four or five new plants.
For something unusual, grow one of the euphorbias as a houseplant. It doesn’t make too much difference which one you choose, neriifolia and antiquorum are equally good specimens. The stems are green, fleshy and three or four angled.
Some kinds of euphorbias, like E. neriifolia have a good crop of leaves; other have but few, in which case they look like bare poles, and some have no leaves at all and are very spiny. So much so that you look a second time to see whether they do not belong to the cereus tribe of cactuses.
The crown of thorns (Euphorbia splendens), is covered with short, stout, sharp spines. The young growth is always covered with leaves and the bright red bracts, surrounding the flowers, are in evidence most of the year. In order to keep the plant within bounds it must be trained on a form.
The Fig Marigolds
Another class of plants which will prove very interesting is the fig marigolds (Mesembryanthemum). The leaves of the various species assume very peculiar shapes and the color varies from a light green to a very dark green. Some of the species flower freely, e.g. tricolorum and Pomeridianum, two annuals.
M. cordifolium, var. variegatum, is a half-hardy, variegated form which is well worth growing as an edging for beds in summer or for rockeries.
Apicra, Haworthia, Gasteria
The apicars, haworthias, and gasterias have curiously shaped leaves. Those of the latter are usually strap or tongue shaped, four to six inches long, dark green in color, and covered more or less with small white spots. In all of the gasterias the leaves are produced in two ranks one above the other. In April and May, and sometimes later in the season, a long flower spike is produced on which are scattered red flowers, which are rather interesting but do not make much of a show unless one has a number of plants in flower at the same time, in which case mass them.
The apricas and hawthornias have short leaves, one and a half inches long, roundish, tapering to a point and are arranged in spiral form around a central axis which sometimes is three or four inches tall.
Another interesting plant which I like to grow is Cotyledon gibbiflora, var. metallica. It has some curiously shaped flowers which are interesting but not showy. Its interest lies in its beautiful purple obovate-spatulate leaves which are sometimes six inches wide and seven inches long. It also forms a big rosette. If you wish to make more plants, break off a leaf at the joint and put it in sand; in a few weeks a bud will develop at the base. I have, however, seen leaves that failed to make a bud. They continued for three or four years to exist simply as rooted leaves.
A good many cotyledons are used during the summer for carpet bedding, but perhaps the most common is C. secunda, var. glauca. This plant is about three inches in diameter and one or two inches high; the flower stalks are always kept pinched out, for the flowers are uninteresting.
Sedums and House Leeks
There are a great many sedums and they are very interesting plants for the home. The showy sedum (S. spectabile) and the live-for-ever (S. telephium), are two that are hardy and can be successfully grown outdoors as well as in the house.
The most common sedum is the stonecrop (S. acre). This is an evergreen and may be used as a hanging plant because the stems will hang down over the sides of the pot, or it may be used in filling window boxes. The leaves are very small (one-quarter of an inch long), but they are crowded closely together on the stems. The foliage is a delightfully bright green and in the variety aureum the shoots are bright yellow in the spring; in the variety elegans the tips and young leaves are a pale silvery color. The sedums are easily propagated by seeds or by the offsets which are freely produced.
The house leeks (Sempervivum) are very similar to the sedums. The most common ones are the common house leek (S. tectorum), and hen-and-chickens (S. globiferum). Like the sedums these are best grown in boxes, but the plants must not be allowed to grow too thickly or they will not flower.
The most interesting one and perhaps the best for growing indoors is the spider web house leek (S. arachnoideum). The leaves, which are short and fat, are borne in rosettes and between the tips of the leaves there are fine, white threads, like a spider’s web. The flowers are bright red and borne on stalks three to five inches high.
Like the sedums the house leeks are easily reproduced by the offsets or even by leaf cutting as suggested for the cotyledon.
Treating Cactus and Succulent Insects and Diseases
The insect pests you’ll most likely see on your cactus and succulents are red spiders, thrips, scales, and mealy bugs. The latter two are easily brushed off with a small brush, but if the stems are frequently treated with clear water, soap suds, or a solution of fir tree oil, these pests will not cause serious trouble.
The red spider will never appear if watering is frequent. Fir tree oil helps to prevents thrips. Try other natural pesticides for your succulents and cactus. Read this guide to organic pesticides for more information.
Be aware that insecticidal soaps will damage some species of cactus and succulents permanently. Insecticides designed for roses often work well for cactuses as well.
Pests can open the way up for fungal diseases so it’s best to treat them as soon as possible. Many pests will die off if you treat the plant with rubbing alcohol as well.
Ron Smith, a Horticulturist with the NDSU Extension Service has an excellent troubleshooting guide to cactus on his website.
If the bottom leaves turn brown should I pick them off or leave them alone?