The Succulent Conservatory
Easy care, low maintenance plant displays for conservatories and garden room
One of the most popular selling points of a home, and one of the most popular additions which home-owners can consider, is a conservatory or garden room. They are so appealing. Despite the vagaries of the British weather, you can be sure that with the slightest sun you can sit out amongst plants and greenery; cooler spring and autumn days no longer mean that you have to be wrapped up outside, or stuck indoors.
Unfortunately, the reality does not always match up to the dream. Time is short. Plants don’t get watered when they should. The sun bakes your prize specimens into drooping brown stems. There must be something you can grow which doesn’t need daily care and attention, and which can be left over a summer weekend without having to make complicated arrangements for their care.
This is where the ‘succulent conservatory’ comes into its own. Most people know that cacti and succulents are drought-resistant plants, adapted to hot, dry conditions. But they also visualise a row of pots, marching like soldiers along a shelf, each containing a small, prickly specimen. Attractive and interesting in their own right, these in no way fulfil the desire for a roomful of luxuriant growth associated with a well-stocked conservatory.
However, the ‘other succulents’ are the key to solving all your plant problems. They come in a wide variety of shapes and sizes, many of them grow quickly, and they can be trained to climb or scramble to soften the edges of pots and benches, or can hang from a selection of attractive baskets. They come in a variety of shapes, from shrubby to rosette forms, and with upright or prostrate growth; and their colours range from the greens you would expect, to a mouth-watering array of pinks, blues, purples, yellows and creams.
The plants have the overwhelming advantage that they will stand strong sunlight which would bake other plants. Although they obviously appreciate watering and feeding in the growing season, they are adapted to surviving periods of shortage, so they can be watered at times which suit you and not vice versa.
Their winter requirements are also simple. Many of these plants will survive happily in an unheated space, so long as they are kept dry.
If you can give them a frost-free environment, with a temperature of as little as 40 degrees Fahrenheit (4.5 degrees C), the range of plants you can grow increases enormously.
A further advantage offered by these succulent choices is that you will have an original and interesting array of plants, which is distinctly different from the usual choices. They are also plants which have an interesting contemporary feel about them, plants which are sympathetic to modern interiors.
There is also a strong case for having a mixed conservatory, with perennial planting selected from the succulent plants which we offer, for a trouble-free long-term backdrop, with shorter term colourful annuals for summer time special effects. You can then concentrate on looking after a smaller number of plants really well, with the daily watering and regular feeding which these choices require, while the rest of your plants wait patiently for you to care for them when it suits you.
Organising Your Display
The most successful displays involve variety of shape and form plus a certain degree of informality. Nothing looks worse than a line of pots with no variation. The ideal format uses an array of staging, with some higher level benching or maybe hanging containers at the top, and plants arranged in a number of levels descending from this point, like a staircase.
Trellis can look very attractive; plants can climb up it, or hanging plants can be attached by their pots to it at a higher level, for the plants to grow down from. Pots can be fastened to walls where plants will grow and spread quite happily; this is where drought resistance comes into its own, because it can be difficult to keep more water-hungry plants sufficiently wet.
Ideally, you need to choose several taller growing accent plants, to give a vertical line, interspersed with squatter plants, and plants which will cascade and soften the formal geometrical lines of the benches.
Larger Plants For Accent Planting
The spiky rosettes of Agave americana and Agave americana ‘Variegata’ grow into huge and striking plants in time; other agaves, like Agave filifera, with fibres developing along the edges of the sword-like leaves, and the Agave americana ‘Mediopicta’, with its pale variegation in the centre instead of the outside edge of the leaves, like Agave americana ‘Variegata’, are also good choices. Aeonium arboreum creates fast-growing branching columns, bearing bright green rosettes and yellow flowers, while its sister-plant, Aeonium arboreum ‘Zwartkop’, bears dramatic, glossy purple-black rosettes. The money plant, Crassula ovata (formerly known as Crassula argentea), especially the colourful varieties like bluey-leaved ‘Blue Bird’ and the yellow, red and green ‘Hummel’s Sunset’, make attractive miniature trees, which can grow to two feet high. Pereskias, the most improbable of cacti, form bushy flowering shrubs. Pitcairnia ferruginea is another spiky accent plant, which grows big in time, and many of the aloes make interesting centrepieces, too.
With patience, you can also grow columnar cacti, like cereus and opuntias; Opuntia subulata is one of the best choices, as it grows rapidly into single columns, branching and clustering in time, or, if beheaded, it rapidly becomes a candelabra-shaped branching form. (Keep the piece you cut off, let it dry off for a fortnight, then you can root it and start another column.) Look also at cephalocereus and trichocereus.
Lower Growing Plants
Echeverias are beautiful rosette-shaped plants in such appetising shades that they function almost as flowers in mass arrangement of plants. They form lovely, sugar-almond coloured rosettes in shades of palest lilac, grey and turquoise, plus some dramatic, dark echeverias in scarlet and deep purple. They can make large plants in time and they make attractive container subjects, surrounding taller, architectural plants like cordylines, agaves or aeoniums. For further information about echeverias, see our article Echeverias For Everyone.
There are lots of pretty crassulas, aloes, sedums and kalanchoes to choose from, too and all of the smaller cacti are interesting for their spination, shape and colour.
Trailing And Climbing Plants
Almost nothing looks better than a selection of climbing and trailing plants, which give an impression of lushness and fecundity which is impossible to achieve in any other way. Traditional hanging baskets can be planted up and suspended, but they will need far less watering than the plants which are usually found in these containers. Look, too, at suspending pots with twisted wire loops.
Some of the plants to consider include Sedum morganianum, which makes a cascade of green tails in time, hence its popular name of donkeys’ tails. Ceropegia woodii has heart shaped leaves and purple lantern-like flowers. Senecio rowleyanus, or string of beads is another dramatic trailing plant which lives up to its name; in time you can have a hanging basket with yards of trailing ‘beads’. These thrive in slight shade and will benefit from plenty of water and feeding in the growing season, when they will fatten up.
Crassula pellucida subsp. marginalis, on the other hand, cannot get enough sun. This versatile plant will colour up into a spectacular maroon in the sunniest spot, its leaves become larger and are bi-coloured maroon and green in slightly more shaded conditions, and become a rich, dark green in deeper shade, while bearing a mass of white flowers in the winter months. Crassula volkensii is also very similar. The arching blue green stems of Sedum sieboldii, and of Sedum sieboldii f variegatum, splashed with white variegation, always look very attractive. Sedum lineare ‘Variegatum’ is another attractive plant, with smaller leaves, forming a pale green cloud, which is good for hanging basket use.
Rhipsalis make lovely branching networks of plants, and bear little white or yellow flowers. They are very easy to propagate from cuttings, so you can soon grow a large containerful. If you keep nipping the ends out of the new growth, set it to one side for a couple of weeks to dry out, then press it into the pot or basket, you will have plenty of new growth. Its delicate filigree habit is very attractive and can make a cloudy backdrop to many other plants.
There are several varieties to choose from, all of which bear tiny flowers in white or yellow. The mistletoe cactus or Rhipsalis cereuscula has the additional attraction of white berries adorning its stems after flowering.
In shadier corners of the conservatory, you can grow one of the many varieties of hoyas. These have glossy, evergreen leaves and bear the most unusual waxy, long-lasting, flowers.
Most of these plants will flower as soon as they are big enough, but if you want to choose flowering plants to act as a strong focal point, you can look at easy to flower cacti, like rebutias, lobivias, mammillarias, notocactus and chamaecereus, which are compact and flower readily. Rebutias, for example, can become totally covered in a mass of remarkably showy flowers.
In a slightly shadier position, kalanchoes are pretty, and some have been hybridised, such as ‘Wendy’ with its pink and yellow bell-shaped flowers, borne in the winter months. Kalanchoe manginii, with narrow dark-green leaves produced in a trailing mass, and profuse, bell-shaped red flowers is another good choice; they enjoy plenty of water and feeding in the growing season.
Succulents also offer a great deal of scope for ‘off-peak’ flowering, which gives the possibility of a mixed conservatory, with traditional flowering choices like petunias and busy lizzies for the summer months, and some more unusual choices for the winter months. Apart from the kalanchoes mentioned above, many of the crassulas offer a mass of flower in the winter months, like Crassula pellucida subsp. marginalis, covered in white flowers. Crassula ‘Silver Springtime’, Crassula socialis, Crassula alba, Crassula lactea and Sedum frutescens are other good choices for winter flowering varieties.
A conservatory offers possibilities for a spectacular Christmas hanging basket display of schlumbergeras, the aptly named Christmas cacti. A cooler conservatory, kept just free from frost, will create the right conditions for a colder weather display, though they may flower a little later in the season if the weather is very cold. The flower colour of these cultivars is temperature dependent and they need temperatures of 12 degrees C / 55 degrees F and above to flower in their true colours. Though this isn’t important with some of the colours, it does mean that whites can develop some pinkness on the base of the petals, and ‘Gold Charm’ turns from yellow to a nasty muddy beige!
Night flowering, scented selenicereus or queen of the night create exotic possibilities. These slender-stemmed plants can be trained to climb, or can be grown in higher-level baskets or pots and allowed to trail. Their flowers are the largest of all the cacti, with their buds opening towards sunset and saturating the air with their fragrance, offering the prospect of enchanting evenings in the conservatory with a glass of wine.
Other epiphytic cacti, like epiphyllums or orchid cacti’ and aporophyllums or rats’ tails create design possibilities; a mass of flowering baskets can create a fabulous ‘jewelled corridor’, with the baskets moved to a less prominent position once flowering has passed. All of these plants have the advantage that they are perennial, and that they will flower regularly once flowering has started, so although you won’t get the repeat flowering of annual plants, they will give you pleasure for many years to come.
Feature Plants Including ‘Bonsai-Type’ Succulents
Cacti and succulents also offer interesting possibilities for smaller, feature planting.
One interesting variation to consider is instant ‘bonsai’. Instead of waiting twenty years (or paying a King’s ransom) for elegant miniature trees, a judicious choice of variety can give an almost immediate substitute. Choose shallow, glazed rectangular and oval dishes for authenticity, making sure there are drainage holes, and plant your selection in any peat-based or soil-based John Innes compost. The varieties of Crassula ovata, mentioned above, will grow into very convincing trees, up to 2 feet or more high in time, with a trunk, branches clothed with succulent leaves and a mass of starry flowers in the winter. Crassula sarcocaulis is another excellent option, this time for a more miniature effect. Again there is a distinct trunk, a branching canopy and masses of pink flowers. Planted in a shallow, earthenware dish, either singly or in a little copse, they are hugely effective.
Sedum frutescens is another desirable selection, with papery bark-like skin, which peels, a little like the bark on silver birch trees. Aichryson dichotomum, the red stemmed Portulacaria afra with its emerald leaves, or its variegated cousin, Portulacaria afra ‘Foliisvariegatus’ are other good alternatives.
Over time, caudiciforms will grow into the most extraordinary plants. Using the same type of shallow container selected for the bonsai-like succulents, these are planted with their engorged roots exposed above the surface of the compost, where their gnarled, rock-like and contorted forms bear branches and leaves like weathered trees. Look at the pachypodiums, Ipomoea platense, Kedrostis africana, Bowiea volubilis, Ficus palmeri and Calibanus hookeri amongst others. Pelargonium carnosum – surely a most unusual member of the ‘geranium’ family – grows into an interesting miniature ‘palm’.
Lithops and other mimicry plants in the living stones families, like conophytums and the windowed fenestrarias, can be planted up in a grouped display. With a judicious top-dressing of gravel and a choice of rounded pebbles, they look immensely appealing.
Interesting Pots And Containers
There is endless scope for using cacti and succulents in group plantings; there’s an almost infinite choice of attractive containers, and they offer the advantage of portability, so that you can ring the changes. When the pot looks at its best, for example when there is a mass of flower, you can feature it prominently, and then you can move it into a less conspicuous position when flowering is over.
Trailing plants look well in strawberry pots, where they can cascade down from their inserts, either as a single mass planting of Sedum morganianum or Senecio rowleyanus, or as a mixed planting. The drought resistance of these plants is very much an asset with a strawberry-pot, which can be hard to keep sufficiently wet for greedier plants.
Tall feature plants like aeoniums and agaves look well rising out of a carpet of scrambling and trailing succulents, which always have an attractive softening effect. Because the colour range of these plants is unusual, with pinks, purples, greys, maroon, bronze and turquoise, which are less often seen amongst the more conventional choice of plants, you have the scope to create some unusual and exciting colour combinations.
Planting into containers also allows you to use your container planting outside in the garden while there is no danger of frost. They make fine accent plantings for outside front doors, on steps, on patios and along paths. (See our companion article The Great Escape for more information on using your plants outside.) In the autumn, they can move back into the conservatory, where they will continue to give you pleasure throughout the colder months.
Cultivation Advice For Containers
Cacti and succulents are unusual in that their main requirement is to dry out between waterings, and they do not like to stand for long periods with ‘wet feet’, especially when the weather is cool and dull.
Make sure that you have a layer of drainage material, which should be up to one third of a large pot. (Those polystyrene chippings which are used a packing material have the advantage of being lightweight and free.) Compost requirements are quite flexible; any house plant compost, e,g, a multi purpose compost, or a John Innes soil-based compost (numbers 2 or 3) are fine; the addition of horticultural grit for extra drainage gives you a safety margin if you think you are inclined to be heavy-handed with watering.
The plants are tolerant, but will appreciate a good soaking approximately once a week in the growing season and feeding roughly once a month with a fertiliser composed to suit tomatoes, or a special cactus compost, like Chempak, which has been formulated for the specific requirements of cacti and succulents. Between November and March, your plants should be kept dry and frost free. This dry period is essential for cacti if they are to set flower the following year. In a warmer conservatory, the true cacti will need an occasional light misting to keep them plump and hydrated and the ‘other succulents’ need a little more water. Many plants will survive in an unheated conservatory, but it becomes of paramount importance to keep them as dry as possible.
Planting Directly Into Beds
Some less elaborate conservatories, like the lean-to ones which do not have a solid base, offer the possibility of planting directly into beds, where the plants will flourish with a freer root run without being as likely to get out of hand as some more usual choices of conservatory plant. Always plant below the level of your damp proof course.
A rockery or raised bed is a possibility where there is a solid floor. Line the bed well with an impermeable liner to prevent damp from coming down from the compost onto the floor, and, again, make sure that the bed or rockery is away from the house walls and the damp proof course.
Try to dig as much extra drainage material as possible into the beds, as these plants flourish in poorer, well-drained soil. Try to arrange your plants to give as much variety of shape, colour and form as possible; this sort of mass planting can be very dramatic. Agaves with a free root run grow like triffids. Cacti, in their natural habitat, have shallow, wide-spreading root systems, so they will appreciate the space to spread their roots beyond the confines of a pot. Hoyas will climb happily and produce waxy clusters of flowers on sinuous branches in the darker corners, while lower growing succulents make multi-coloured carpets.
You can still make very flexible displays if you bed plants in their pots into a well drained raised bed and dress the surface with gravel to hide the rims of the containers. Flowering plants can be moved in and out when they are at their best.
Below, an internal rockery makes an interesting display area for your plants; it can look very natural and again you can bed plants in the pots if you would prefer to keep the arrangement as flexible as possible, though the plants do love a free root run. Add a waterfall or other small water feature for the added pleasure of the sight and sound of moving water.
Succulents For The Birds – Using Your Plants in Unusual Settings
At the nursery, we once had half of our conservatory converted into an aviary for a collection of foreign finches, which used to fly freely around outside our living room, alighting on perches made from natural branches brought in from outside. Unfortunately our original attempts to clothe the space with shrubs and flowering plants in containers wasn’t an unmixed success. Access, through double doors to trap escapees, was never easy, and the amount of water needed created problems, with the environment easily becoming too wet for the birds.
Eventually we changed to an assortment of mass planted succulents in large containers, plus hanging baskets and a little judicious planting into the soil at the edges of the aviary.
This was a huge success. The plants grew and thrived with far less watering and the birds were much happier and a lot less bedraggled than under the old regime, and the plants, like the birds, were kept frost free over the winter. Sadly our finch Eden came to an end when it also became home to generations of mice – from big fat grandfather mice down to tiny babies – living on the bird seed, hanging on the millet and generally running riot. The mice couldn’t be trapped or poisoned because of the birds so, in the end, my finches went to new homes and the conservatory was no longer bird heaven.
We have heard of tortoises living alongside smooth skinned opuntias (and feeding on them!) and have seen terrapins and exotic reptiles living in containers landscaped with succulents.
Water is always a delight, and you can create magnificent succulent and cactus rockeries incorporating water features. Keep the ‘other succulents’ for planting alongside the water margins as they enjoy more water than the true cacti.
However, electricity and water are potentially lethal so do get a qualified electrician in to do the fitting if you have any doubts above whether you can install the system yourself or not.
Water is also a magnet to small children so this is something to put on hold if you have toddlers, although a small bubble pot like the black water feature photographed. is a safe alternative to open water.
General Care for your Beds and Rockeries
All cacti are succulents but all succulents are not cacti. The so-called ‘other succulents’, which include lithops (living stones), crassulas, echeverias, sedums etc., differ from cacti in generally having leaves rather than the spines surrounded by hair which are characteristic of true cacti. The ‘other succulents’ prefer more water and a bit more shade than true cacti apart from living stones which love to be baked.
During the winter all cacti (except Christmas cacti which flower then) should be kept as dry as possible from around November to March. Keeping plants dry in an unheated conservatory also increases the resistance of the plants to cold. In a heated conservatory, a light misting will be needed but less is always more.
In the spring a little more water should be given and the amount increased gradually, until the plants are being watered once or twice a week by the summer. When they are in full growth they will appreciate feeding every two or three weeks with Chempak, or any other specially formulated cactus fertiliser; you will find that they are happy with tomato fertilisers too.
In the autumn gradually reduce the watering again, in order to rest the plant during the winter; this also encourages the plants to flower in the following year, as they need a period of dormancy to produce their buds.
Cacti and succulents suffer from very few pests and, apart from aeoniums, they are not susceptible to attack by greenfly, blackfly and whitefly.
The main pests of cacti and succulents are mealy bugs, which may occur on the roots, stems or leaves. They are not likely to kill your plants but they are unsightly and spread, slowly but steadily, to infest all your collection. If you have plants bedded into the soil it is absolutely vital to keep them under control as they can hide in nooks and crannies. Fortunately mealy bug can be eradicated easily by using Intercept, which is found in Provado. Although this is marketed as a vine weevil killer it is also brilliant against mealy bug.
Low-grade infestations can be treated with methylated spirits dabbed on with a cotton bud, or spraying with a solution of soapy water.
This is also a good treatment for less frequently seen pests, like scale insect and red spider mite, though you might have to use a systemic insecticide for more serious infestations. Red spider mite can be deterred by misting the plants and good ventilation, as these bugs like dry conditions.
Overwatering is the main cause of cacti dying and even this is difficult to achieve in the summer months with well-established plants.
However, the winter is the dangerous time, when the plants have stopped growing and evaporation from the pots is slow. These plants do not have our native species’ natural resistance to moulds etc., and, although it sounds harsh, we recommend that very little or no water is given in the winter, which will ensure that your plants survive to give you pleasure for many more years.
Some Recommended Plants
Because of their drought-resistance, true cacti and the other succulents are all ideal for a conservatory and will need far less care than any other plants. When choosing plants for your conservatory or garden room, the following lists will act as a starting point:-
True cacti – Cereus, cephalocereus, trichocereus, opuntias, pereskia
Other succulents – Agaves, aeoniums, aloes, larger growing euphorbias and crassulas
True cacti – Globular cacti
Other succulents – Echeverias, crassulas, aloes, sedums and kalanchoes
Trailing and climbing
True cacti – Epiphyllums and aporophyllums, rhipsalis
Other succulents – Crassulas, sedums, kalanchoes, hoyas, ceropegia
True cacti – Rebutias, lobivias, mammillarias, notocactus, sulcorebutias and chamaecereus
Cultivars bred for flower – Epiphyllums, aporophyllums, selenicereus and Christmas cacti
Other succulents – Kalanchoes, crassulas
True cacti – Cristate and monstrous plants
Other succulents – Living stones, miniature ‘trees’ like some crassulas, caudiciforms
In conclusion, there are many exciting possibilities for using cacti and succulents in an easier to maintain conservatory or garden room, where you will no longer be such a slave to the watering can.
We would always be interested to hear from any of you if you have a particular stroke of inspiration which you would care to share with our other customers.
Good luck and happy growing from us all here at Glenhirst Cactus Nursery!