Conservatory Rooms: Growing Plants
Plants for the conservatory
Having organized your basic structure, don’t spend all your money on furnishings before stocking up with plants. When entertaining in your conservatory room you can always import furniture from other rooms for the occasion.
Wall shrubs and climbers
You should now mount the house wall with wires or a trellis since most of the plants for this wall will cling by tendrils, or via twine, or be low-growing shrub types. The border next to the wall can be narrow — 60cm (24 in) in width is ample. But it is best to dig it out to a depth of 45-60cm (18-24 in) and, along with the other borders, fill it with compost such as J.I. No 3. Try to use evergreen climbers as bare stems are out of place in a conservatory where the last thing you want is a feeling of bleakness.
The winter-flowering jasmine Jasminum polyanthum is easy, reliable and astonishingly vigorous too. The clusters of starry, heavily banana-scented whitewill fill the whole place with an exotic perfume from early to (February to late March). You will rarely see it flower as you will if you grow it like this. It needs plenty of water so don’t let it dry out. You should also cut it back severely after flowering, otherwise the whole wall will be taken over.
Albizia lophantha (sometimes known as the pink siris, or Nemu tree) is a lovely shrub when grown against a wall. The finely-divided leaves are attractive in themselves but when the pale lemon, fluffy flowers appear in winter (borne in profusion from December onwards), it is a truly magnificent sight. When seen in the half light or dusk, these flowers possess an almost luminous, ethereal quality. It will grow fast and if you need to prune it remove only the previous year’s wood immediately after flowering. Albizia is closely related to acacia and so hates hardand may die back as a result.
Streptosolen jamesonii is a loose-growing shrub that needs support. Orange flowers appear in large clusters from early to late summer (May to July) after which you can prune it. It’s a forgiving plant and copes with pruning surgery quite well. Watch out for greenfly though. They seem to be very fond of this plant, and whitefly have been known to cause problems as well. Sprayings of malathion at five-day intervals over a couple of weeks will soon put paid to them.
Plumbago capensis (Cape leadwort) is superb for clothing walls. Its showy heads of light-blue flowers appear throughout most of the summer. P.c. Alba is a white form that some people prefer.
Eccremocarpus scaber (Chilean glory flower), a type of climbing plant that becomes woody, is to be recommended. It is a vigorous plant and produces scarlet and yellow flowers throughout the British summer. Do not be afraid to cut it back hard each year. It can become untidy if left to its own devices. A rare yellow form, Eccremocarpus s. Lutea, can sometimes be found.
Rhodochiton atrosanguineum (purple bells) is a curious though unspectacular climber that is well worth trying. This quaint plant with slender stems bears drooping, blackish-purple flowers in summer and makes an unusual display.
Passiflora caerulea, the common blue passion flower, should in no circumstances be planted under glass because it is far too vigorous. It grows well on a sunny wall out of doors unless you live in a particularly cold area. It is better to make room for P. antioquiensis (or Tacsonia van-volxemii), one of the red passion flowers. It will grow and flower well when established and is best trained up the walls and across the roof so that the hanging red flowers can be seen to their best advantage. P. racemosa, that has scarlet and purple flowers, is worth establishing. Both require a lot of room, though, and do take a while to settle in before producing flowers.
Another climber that can be shy about coming into flower when young is, surprisingly, one of the honeysuckles, Lonicera hildebrandiana. It is far too tender for all but the warmest areas but, where space allows, this giant honey-suckle should be grown. Huge, leathery leaves, 15-18cm (6-7 in) long, make the plant seem uncharacteristic of the family. But when you see the 10-15cm (4-6 in) long, creamy-white flowers changing to yellow and occasionally flushed with orange, there is no mistaking it or its truly delightful perfume.
Two climbers you might like to bear in mind that do better out of pots are the Bougainvillea glabra and Gloriosa rothschildiana. The bougainvillea and its many hybrids with showy bracts of pink, salmon-pink, orange, purple and white, is spectacular in summer. G. rothschildiana is a climbing lily that dies back to aeach autumn. The reflexed orange and yellow sepals and petals live up to their name of ‘glorious’.
Border shrubs and perennials
The borders along the sides of the conservatory can be planted with numerous shrubs and herbaceous plants. Always treat this part of the conservatory as though you were planting a shrub border in the garden, and plan beforehand. The following suggestions will help you to make your choice.
Nerium oleander (oleander) is a large leafy shrub bearing pink, rose-red or white flowers that can be single, semi-double or double. There are also variegated forms that are worth searching for. Always choose a scented variety: some plants offered for sale are unscented and the loss of that heavy, vanilla-like odour is a great pity.
rosa-sinensis comes in such a wide range of colours nowadays that a choice is difficult. Large flowers, both double and single, can be had in deep rose, scarlet, orange, maroon and even yellow. They’ll grow into sturdy bushes in the border and these, together with the oleanders, will probably need pruning after a while. However, do not worry if you prune in mid spring (March) as they will come to no harm.
One shrub you should not be without is Tibouchina urvilleana (Brazilian spider flower). It has large, velvety, deep purple flowers right up till early winter (November) and the soft, hairy leaves develop orange tints before falling. Cut it back hard in mid spring (March) to prevent it from dominating a whole border.
You will probably be familiar with that fast-growing plant Grevillea robusta (silk bark oak). Where space allows it should certainly be allowed to develop. Apart from its silky, lacinate leaves it can, when old and large enough, produce clusters of bright orange flowers.
The smaller Grevillea rosmarinifolia is a cousin that bears no resemblance in size or leaf. It grows to 1.8m (6 ft) and looks almost gorse-like from a distance. The flowers are freely produced even on a young plant and are bright red.
Palms, despite what some people would have us believe, love to have a free root run and you should try Trachycarpus fortunei (fan palm) that grows slowly up to 3m (10 ft) or so, Neanthe bella (dwarf parlour palm) that rarely exceeds 90cm (3 ft) and the feathery Phoenix canariensis. The last will eventually become very large so you will either have to take an axe to it or have the roof raised.
There is, however, a dwarf form, P. roebelinii, that grows slowly to 1.8m (6 ft).
Other shrubs that will do well in your border are proteas, with their huge quilled flowers and stiff, upright growth. They require full sunlight to do well and their root systems are much happier in a border than in a pot. Jacarandas are primarily foliage plants with soft, ferny leaves, but given time they will produce clusters of lovely blue flowers.
Prostantheras are not only valuable for their aromatic foliage but also for the freedom with which they produce their lovely flowers. P. rotundifolia, a neat, little shrub that grows to 90cm (3 ft), bears masses of light heliotrope flowers in mid spring (March). Salvia leucantha is a far cry from its edible cousin Salvia officinalis (common sage). The stems and undersides of the leaves are thickly white-felted, so too are the flower spikes, but it is the intense magenta flowers seen through this white felt that make the plant unique.
There are other plants besides shrubby ones that will enhance your conservatory. Gerbera jamesonii (Barberton daisy) with daisy-like flowers produced almost throughout the year is essential. Modern strains will give many shades of yellow, orange and red. Clivia miniata, one of the Kaffir, is a joy in spring. It has umbels of orange and yellow flowers amid its leathery foliage. Orchids are hard to ignore and one in particular — ideal for conservatory borders — is Bletilla striata, the Japanese Geisha orchid. Its small, 4cm (1-1/2 in), flowers are glistening purple and, when given a free undisturbed root run, the plants can produce up to 15 flowers per growth on 60cm (24 in) stems.
In shadier spots all manner of ferns will grow to sizes never possible in pots. Adianturn cuneatum Fragrantissimum (maidenhair fern),bulbiferum (spleenwort) and Cyrtomium fakaturn ( fern) are best.
Plants for staging, tubs or urns If staging is incorporated in the conservatory, you can use this for temporary displays of annuals or plants such as begonia, charm and cascade, cyclamen, gloxinia and primulas. These, together with forced bulbs, will help to increase the floral display throughout the year.
Some plants are of such architectural value they look better singled out in tubs or urns. Strelitzia reginae, the fabulous bird of paradise flower with spikes of blue and orange, is particularly fine. Agave americana Variegata, the variegated century plant, is a beauty when large but beware of its vicious spine-tipped leaves.
Zantedeschia (arum lilies) always outgrow their welcome when given freedom so restrict them to a tub where their handsome leaves can best be appreciated. There are yellow and pink forms too.
These are the ones to buy: Zantedeschia aethiopica, Zantedeschia albo-maculata (both white but the latter has spotted leaves), Zantedeschia elliottiana (yellow with white-spotted leaves) and Zantedeschia rehmannii (pink arum).
Having looked at plants within the conservatory, you must not neglect the world outside. Your new ‘room’ should not just be part of the house but part of the garden too. Blend them together by training slightly tender shrubs along the outside walls of the conservatory where they will flourish in the protection of the walls. Plant Callistemon linearis and Callistemon citrinus in a dry, sunny position. These scarlet bottle brushes will provide a riot of colour in summer and their flexuous stems lend themselves admirably to training along a wall.
Acacia verticillata (prickly Moses) is a wonderful plant that hates severe cold but, if trained along a sunny wall, it will astonish you with a show of canary-yellow miniature brushes in late spring (April) and early summer (May).
A single garland of the purple-leaved Vitis vinifera Purpurea (Teinturier grape), trained along the guttering on a wire, is very effective. Cut it back hard to prevent light being shut out.
Maintenance and protection
All plants, whether in pots or in the border, will be all the happier for a liquid feed at 10-day intervals in spring and summer But if your borders are so large as to make this impractical, then a top dressing with a standard fertilizer will do. Make sure none of your plants become dry at the roots and if you can spray overhead daily so much the better.
The more common pests you will encounter and have to deal with include aphides, red spider mites and whitefly. They are all sap-sucking pests that if allowed to multiply will cause serious damage. Red spider only thrives in a dry atmosphere so overhead mistings of water are the best means of protection.
Aphides and whitefly appear at any time and the best way to control them is to use one of the many insecticides available. Always make sure you follow the instructions carefully, otherwise more harm can be caused by pesticide than pest.
So, at its best, the conservatory is an indoor garden, a real link between the house and the outdoor garden, and a living room that can give lasting pleasure, comfort and enjoyment.