Plants for Intermediate Temperatures

With a constant winter temperature of from 55 to 60 F (13-16°C), the choice is very much wider and many more colourful specimens may be grown. Perhaps the most gorgeous of all are the plants known in the U.S.A. as the Ti tree, Cordyline terminalis. These are small palm-like plants with leaves up to a foot in length and 4 in. across, which first unfurl with the most brilliant colours in cerise, pink, or cream and pink and which gradually age to a purplish brown or a medium green with a red margin, but practically any combination of red, pink, cream and green can be found in the various cultivars. Since they grow more or less continuously, the appearance of the plant is constantly changing.cordyline Unfortunately, these gorgeous colours do not appear until the plant has been growing some three years, so that they are not cheap to purchase. They are greedy feeders requiring a rich soil mixture and ample feeding. They should be potted on every two years. They must have a well-lit situation, but not in direct sunlight for too long and they require ample water, but should not be over-watered. Since the leaves are more brightly coloured than a good many flowers, it can be appreciated that this is a fairly striking plant. It is never stopped.

The Croton, Codiaeum variegatum, is equally colourful, but not quite so easy as it is very sensitive to draughts, which can cause the leaves to fall, and also to any violent fluctuations in temperature, which can also have bad results. If the temperature can be kept constant, the plant will thrive. The leaves vary in shape from nearly circular to almost grass-like and are in various combinations of brilliant colours. This can be kept somewhat on the dry side during the winter, but will take plenty of water during the summer. The plant contains a milky juice, which spurts out whenever the plant is damaged in any way, so this should be avoided and the plant is never stopped. It requires ample light at all times and has no objection to direct sunlight. It is by no means one of the easiest of house plants, but it is very showy. Potting on should take place every other year.

Very much easier are the Rex begonias. These have roughly triangular leaves, which may be fairly regular or which may have very jagged edges and these leaves are gorgeously coloured in varying shades; some are deep or rosy purple, others varying shades of green and silver; the choice is very large. They have no objection to shady conditions and will still keep their gorgeous colours in such situations. Begonias have very fine roots and are usually grown in a mixture composed mainly of leaf mould and sand, with only a little loam so that soilless mixtures will prove very satisfactory. They must not dry out at any time, but they do not require to much water either and should be watered regularly. Rex begonias spread outwards rather than upwards and they can be divided, if the plant is getting too large. The plants should be fed during the summer, but rather sparingly. The ‘Iron Cross’ begonia (B. masoniana) needs rather warmer conditions than the rex group and has bright green leaves with a maroon ‘Iron Cross’ in the centre.

The zebra plant, Aphelandra squarrosa louisae, has an upright stem from which spring pairs of leaves,Zebra plant - Aphelandra squarrosa which may be 9 in. long and half as wide. These are a dark green, with the main veins picked out in bold ivory stripes. The original plants used to produce pyramidal heads of yellow flowers, but the later forms, known as ‘Brockfeld’ and ‘Dania’ flower very rarely. The plant needs repotting yearly and takes ample water during the summer and a certain amount in the winter. Sideshoots can be detached and rooted in the summer, but a temperature of at least 65°F (18°C) is necessary and preferably somewhat higher. These plants need a reasonable amount of light, but will grow in partly shaded conditions quite satisfactorily.

The various ficus are not particularly colourful, but they are impressive. The most popular is the indiarubber tree, F. elastica, which is offered either as var. decora, which has the immature leaf covered with a red sheath, or as var. robusta, which has very large leaves, somewhat rounder than those of decora. There are also some handsome variegated forms known as `Schryveriana’ and ‘Tricolor’, with their leaves blotched with cream, light and dark green, which are somewhat more decorative. The India Rubber Plant can eventually make an enormous tree, so it is kept to reasonable dimensions by keeping it in a small pot, 5 or 6 in. in diameter, and feeding it during the summer to get the leaves a good size, but not to encourage much stem elongation. Their large leathery leaves must be sponged regularly on both surfaces to keep them glossy and to stop any possible infection with scale insect. They can be kept fairly dry in the winter and watered normally during the summer, when they will much appreciate the leaves being syringed during very hot spells. They will grow equally well in shade or sun, although they should be in the shade when the new leaves are unfurling,ficus benjamina otherwise these will not be a good size. Ordinarily you do not stop at all, but if the plant gets too tall, it can be cut back in spring to about 6 in., when it will break again from the base. This is a messy job as the plants are full of milky latex (from which rubber can be obtained) and this will gush out and stain the plant. The cut surface should be sprinkled with powdered charcoal immediately to stop excessive bleeding. Ficus benjamina is another member of this genus, which makes a branching, thickly-leaved tree with long narrow leaves giving something of the effect of a weeping willow. Some of these leaves will be shed in the winter whatever you do, as it is their natural habit, but many more will be produced in the following spring and summer. This needs a well-lit but shady position and will take rather more water than F. elastica.

There are many philodendrons used as house plants; most of them are climbers, producing aerial roots, but one striking plant, P. bipinnatifidum, does not climb, but forms a rosette of long-stemmed very jagged leaves, which get larger as the plant grows and can end up a yard across. The leaves also get more jagged as the plant matures; the first leaves are heart-shaped. As the larger plants are handsomer, they are potted on yearly until they are in a 7- or 8-in. pot, in which they can then stay, being fed regularly each season. With these larger sized plants clay pots are better than the plastic ones, that are so light that a large plant makes them top heavy. This plant is never stopped. On the other hand the climbing species are stopped from time to time, although not necessarily every year. These climbers all require shady conditions, although these should not be too dark, whereas P. bipinnatifidum, will grow either in shade or in full light, although the leaves seem to be larger in the shade. Ideally the climbing forms should have a very damp atmosphere from which their aerial roots can obtain nourishment, but they are often tolerant of quite dry conditions. They are sometimes trained on blocks of cork bark, to which the roots adhere and which is quite easy to moisten. The most attractive, but a delicate, rather difficult plant, is P. melanochryson, with heart-shaped, dark green, iridescent leaves, 5 or 6 in. long. Much easier are the popular P. scandens, with green heart-shaped leaves, and two very similar species, P. hastarum and a plant called P. `Tuxla’, both of which have spear-shaped leaves about 7 in. long and 4 in. wide. They are a shining dark green, with some coppery sheen in the young leaves. These latter are fairly slow growers, whereas P. scandens is quite fast and benefits from a yearly stopping. If it becomes too tall you can bend the flexible main stem right over and tie it in at the base of the plant, whence it will start to climb anew. A plant needing similar treatment to the climbing philodendrons is Monst era deliciosa borsigiana. This has large serrated leaves, which are perforated with holes, giving a very exotic outline. In dark shade these perforations will not develop. It is best trained upright and the aerial roots carefully guided down into the soil in the pot. Stopping is not recommended unless the plant is getting too large, as it is slow to break again. Similar to P. scandens, but with gold variegated leaves is Scindapsus aureus, which needs more light than the philodendrons and requires a yearly stopping.

Aralia ( Dizygotheca) elegantissima makes a slow-growing shrub with leaves like those of a horse-chestnut in shape, but the leaflets are extremely thin in young plants, becoming wider as the plant ages. They are coppery red when they emerge but become very dark maroon, almost black. This may not sound very attractive, but the plant has enormous grace and charm, as much from its elegant habit as from its light, graceful leaves. It requires a well-lit position, but shade from much direct sunlight and the leaves should be syringed frequently during the summer and occasionally during the winter to discourage red spider. On the other hand the soil is always watered somewhat sparingly, particularly in the winter.

Mother-in-law’s Tongue, Sansevieria trifasciata laurentii, makes an upright plant, with its stiff, fleshyMother-In-Law's Tongue leaves; which are mottled in light and dark green with a golden margin.

The plant usually produces only one extra leaf each year and this may turn up some way from the rest of the plant. There is a temptation to cut this out to form another plant, but this should only be done the year after it has appeared, as it does not produce any roots the first year and the plantlet would probably die. If, when the leaf is about 8 in. long, you can find the underground stem from which it rises and cut this half-way through with a knife, this seems to encourage rooting. This plant needs ample light and very little water. In the winter one watering a month is sufficient and even in the summer it should be allowed to dry out thoroughly between waterings. The new leaves are somewhat rolled in to start with and water should not be allowed to lodge in this hollow, otherwise the root could rot. Otherwise they are tough resilient plants, which will put up with almost any conditions and tolerate oil or gas fumes.

Peperomias are low plants, with a very small root system. Some have trailing stems, but the most attractive throw up a tuft of leaves from a central point. The best are probably P. hederaefolia, P. caperata and P. sandersii. P. hederaefolia has heart-shaped leaves some 2 ½ in. long and 2 in. across, which have a quilted effect from the undulating surface. They are pale grey with olive green main veins. In the autumn it produces flowers that look like white mouse tails. If a leaf is removed and inserted shallowly in a cutting mixture with the temperature not below 65°F ( 8°C) a small plant will arise from the base of the leaf. P. caperata has smaller corrugated leaves, the peaks appearing greyish, while the valleys have a purple tinge. The flowers are pure white. It is propagated the same way as P. hederaefolia, but the stalk can be inserted a little deeper. Both these plants like shady conditions and never a great deal of water around the roots, although they revel in a moist atmosphere. The rugby football plant, P. sandersii, is the most handsome of all the peperomias, but is not very easy, requiring a winter temperature of 60 F (16°C) and great care in its placing as it is very sensitive to even mild draughts. The striking leaves, shaped like a rugby football, are silver with green zones around the main veins. Keep the plant as dry as possible in the winter; the leaves can flag before you need apply water as they come back without damage.

The calatheas and marantas all have very attractive leaves. They must have moist, shady conditions and the plants need ample feeding during the summer. They will probably need potting on yearly. If plants get very large, they can be divided. Although they will pass the winter happily at the temperatures recommended, they need about (5 ½ °C) more during the summer to make proper growth. Direct sunlight can shrivel the leaves, so should be avoided. The plants are sometimes known as prayer plants, as they raise their leaves at night. Calathea insignis has elongated oval leaves, 4-9 in. long; they are yellowish green darkening towards the leaf margin and with dark green blotches along the midrib, while the underside of the leaf is a deep claret colour. P. mackoyana is very striking with rounder leaves, about 6 in. long and 4 in. across. The main portion of the leaf is silvery in colour with dark green blotches, underside rosy purple, so that the plant has a rosy glow. Maranta leuconeura is a variable plant, rather lower than the calatheas, its leaves usually about 4 in. long and 2 ½. across. The var. massangeana has leaves of soft green with the main veins picked out in white to give a herring-bone effect, while the var. kerchoveana has leaves that when young are emerald green with red blotches between the veins, while in older leaves the colours are dark green and maroon. The var. erythrophylla (tricolor) has larger, very dark green leaves, the main veins bright red, with yellowish-green blotches between them.

Sorry, comments are closed for this post.