Philodendron bipinnatifidum (finger plant) origin: Brazil.
An easy, compact plant normally sold in a 5-in. Pot. The mid-green, triangular leaves have an irregular serrated edge and rise from a central point. They are usually about 12 in. long and 9 in. across, but sometimes much larger. Place the plant in a semi-shaded position in summer, and give it more light, though not direct sunlight, in winter. Keep evenly moist in summer, but allow almost to dry out between waterings in winter. Feed regularly during the growing season. This species grows slowly and the lower leaves may turn yellow and fall off, but are replaced by new and larger leaves.
P. melanochrysum (black velvet) origin: Colombia. A delicate climbing plant, which may be trained on a mossed stick. The heart-shaped leaves vary from 3 to 5 in. in length and have a most exotic appearance, with a velvety, very dark green, almost black surface and a deep golden underside. The plant requires moist conditions, a minimum temperature of 55° F. (13° C), and a semi-shaded, draught-free position. Always water with tepid water.
P. scandens (sweetheart plant) origin: Puerto Rico, Panama. A popular and attractive climbing plant, which produces aerial roots at every leaf joint and will grow larger leaves if trained up a mossed stake as described in Pruning and Training. It has heart-shaped, dark green leaves some 3 to 4 in. long and 21 to 3 in. wide, although they can be much larger in mature specimen plants. Will survive in almost any conditions, but thrives best in warmth and humidity. Likes a semi-shaded or shaded position and will tolerate quite dark corners. Prefers moderate watering and regular feeding during the summer. Keep the plant fairly dry in winter if in a cool position. During winter and early spring it tends to make weak, thin growth (elongated with small leaves), which should be removed to encourage fresh “breaks” and stronger growth.
P.s. Variegatum. The variegation is usually confined to one half of each leaf and consists of green splashes on an almost white background. This variegation often causes severe distortion of the variegated half of the leaf and is almost certainly virus induced.
P. selloum, although this is almost indistinguishable from P. bipimmtijidum when small, and is often sold as the same plant, it forms a trunk when larger, and has larger leaves, with deeper serrations. P. wendlandii (bird’s nest philodendron) origin: Costa Rica, Panama. An intermediate plant quite unlike other philo-dendrons in habit and leaf shape. The long, lance-shaped leaves are a glossy dark green, and stand up stiff and erect rou nd a central point. The leaves of specimens in 6- or 7-in. pots reach a length of 20 to 2-1 in. and are some 3 to 3j in. wide. The plant often produces an exciting cluster of two or three beautiful cream and deep red flowers in the centre of the cone of leaves. The flower has a stem about 3 in. long, and lasts for only about 2-1 hours when cut. The plant requires a semi-shaded position away from direct sunlight, and should be kept moist. Feed during the growing season, and never subject the plant to a temperature of less than 50° F. (10° C).
PHILODENDRONS (tree lovers) belong to a largeof mostly climbing plants prized for their striking, leathery leaves. Flowers are rarely produced in potted specimens and are relatively insignificant when they do appear. In the wild the stems of most species grow up the trunks and branches of trees by sending out aerial roots at each leaf node; the roots attach themselves to the surface of the bark. These aerial roots can take up nutrients, but the main source of food for philodendrons is the soil and is taken up by the roots that penetrate it. Indoors, climbing species can reach a height of 6-8 feet when they are trained up or moss-covered poles (see “Special points,” below). Some of the smaller-leaved kinds, however, are often grown as trailers. The few species that do not climb form an upright stem that rarely grows more than 6 inches tall. This short, usually stout stem carries a loosely arranged rosette of leaves.
The leaves of different species of philodendron vary considerably. They may be heart-, lance-, arrow-, or spatula-shaped. They may be smooth-edged, slightly indented, or so deeply lobed that they appear to be divided into leaflets. Many look entirely different in shape and size when the plant is mature from the way they looked when the plant was young. This last characteristic should be borne in mind when the amateur gardener is buying a philodendron. Young plants sold as distinct species can disappoint by growing into familiar ones. Leaf colour is normally glossy green, sometimes with some red colouring on the underside, occasionally with a reddish tinge across the whole leaf surface. The leafstalks are between 2 inches and 2 feet long.
P. angustisectum (also known as P. elegans) has climbing stems that can grow 4—6 feet tall indoors when sup-ported on a stake. The leaves are broadly oval, 15 inches long and 12 inches wide, and deeply cut into many narrow, dark green, fingerlike segments, often little more than 1 inch wide. The leafstalks are about 12 inches long.
P. bipennifolium, commonly called panda plant, fiddle-leaf, or horsehead philodendron, is a climbing plant that can rapidly grow to 6 feet tall. Leaves on young plants are somewhat heart-shaped. As a plant ages, however, its leaves become roughly fiddle-shaped (narrowed in the middle, like a violin), but with a pointed tip and two pronounced lobes at the stalk end. These leathery, pale olive green leaves are up to 15 inches long and 8 inches wide on 12-inch-long stalks. Plants of this species need to be supported by stout stakes.
P. bipinnatifidum is a large non-climbing species that can attain a height of 4 feet in a pot. The roughly arrow-shaped, dark green leaves are 15 inches long and 15 inches wide with 12- to 15-inch-long leafstalks arranged in a loose rosette radiating from the central crown. The leaves are so deeply incised that they appear to be cut into separate leaflets, but they are not; the cut goes almost—but not all the way—to the midrib. The plant eventually produces a short, thick, trunklike stem. Leaves of young plants are more nearly heart- than arrow-shaped, and their edges are only slightly indented, giving no indication of the deep marginal serration typical of the leaves in mature plants. P. ‘Burgundy’ is a hybrid of mixed parentage. It climbs much more slowly than most—no more than 3-6 inches a year—and seldom requires the support of anything bigger than a short stake. Its spread exceeds its height because the closely spaced leaves are held upright on 12-inch-long, horizontal leafstalks. The stalks, as well as the stout stems that bear them, are red. The lance-shaped, 12-inch-long, 4-inch-wide leaves are olive green on the upper surface and deep burgundy red on the underside. For their first few weeks, however, new leaves are bright red. P. erubescens (redlcaf or blushing philodendron) is a strong climber that grows over 6 feet tall when well staked. The leaves are arrow-shaped, 10 inches long, and 7 inches wide, with shiny, dark green upper surfaces and coppery undersides. The 10-inch-long leafstalks as well as the central stems are reddish purple. P. imbe can attain a height of 8 feet in only a few years if supported by strong stakes. The thin but firm-textured leaves are heart-shaped, 10 inches long, 5 inches wide, and mid-green. They are borne on 12-inch-long leafstalks, which extend horizontally from the stems, so that the plant has a layered appearance. In some forms of this species the leafstalks and undersides of leaves are faintly tinged with red.
P. melanochrysum (often called P. andreanum; popularly known as black-gold philodendron) is a slow-growing climber that can attain a height of 6 feet. Its leaves are heart-shaped when the plant is young, but they lose their curves and become elongated as the plant ages. The upper surface of the leaves, which can grow 2 feet long and 9 inches wide, is a velvety, blackish green, with prominent pale green vein areas. The leaves hang down from 18-inch-long leafstalks that are held in a semi-upright position. This species needs to be attached to a moist, mosscovered stake in order to show to best advantage.
P. pedatum (sometimes called P. lac-iniatum) climbs so slowly that a 4-foot stake will normally support it until it is several years old. Its shiny, mid-green leaves are about 10 inches long and 7 inches wide and are carried on 10-inch-long leafstalks. Each leaf is basically divided into five lobes. The lobe at the leaf tip is spear-shaped, and the four other lobes may themselves be double-lobed. P. scandens (heartleaf philodendron) is the most popular small-leaved climbing philodendron, and one of the easiest of all house plants to grow. Its slender stems carry heart-shaped leaves 4 inches long and 3 inches wide with 2- to 3-inch-long leafstalks. The leaves, which have acutely pointed tips, look slightly bronzish and almost transparent when they are new, but they quickly become deep green as they grow to maturity. This plant can be grown as a climbing or trailing specimen, depending on whether its long stems are trained up supports or are allowed to trail over the rims of pots or hanging baskets. Experienced growers recommend regular pinching out of the growing tips in order to make P. scandens bushy. Otherwise, the stems tend to grow too long, giving the plant a skimpy look.
P. selloum does not climb. It forms a rosette of leaves that eventually rise from a short, thick, trunk-like stem. The 12- to 18-inch-long, 12-inch-wide leaves have arching, 18- to 24-inch-long stalks. This species is very similar in appearance to P. bipinnatifium, except that the leaves are smaller and less incised.
P. wendiandii is a non-climbing species with a rosette of 12- to 18-inch-long, lance-shaped leaves with 6-to 9-inch-long leafstalks. Each glossy, dark green leaf has a prominent midrib, which widens from a thin, raised line at the tip of the leaf to a 1 -inch-wide bar at the base.
Light Grow philodendrons in bright filtered light, but out of direct sunlight. Although they will survive in poor light, the stems will elongate unnaturally, and the plants will lack their characteristic close growth and striking leaf colour.
Temperature Normal room temperatures are suitable. Philodendrons cannot tolerate temperatures below about 55°F.
Watering During the active growth period water moderately, giving enough at each watering to moisten the potting mixture throughout, and allowing the top half-inch of the potting mixture to dry out between waterings. During the short midwinter rest period water only enough to keep the entire mixture from drying out completely.
Feeding Throughout the months while philodendrons are actively growing apply standard liquidonce every two weeks.
Potting and repotting Use a combination of half soil-based potting mixture and half leaf mold or coarsemoss. Move philodendrons into containers one size larger only when their roots have completely filled the current ones. Do this at any time of year except during the short rest period. After the maximum convenient pot size (probably 10 or 12 inches) has been reached, an annual spring top-dressing with fresh potting mixture will help keep these plants healthy.
The best type of container for big specimens of the three large-leaved, non-climbing philodendrons—P. Bi-pinnatifidum, P. selloum, and P. wendiandii—is a small tub 12-15 inches across. Such tubs have a broader, firmer base and less height than the standard pots. Plants that are grown in them are far less likely to become dangerously top-heavy than those philodendrons that are grown in the standard containers.
Propagation To propagate climbing philodendrons, use 3- to 4-inch-long tiptaken in late spring or early summer. Take each cutting immediately below a node, remove the lower leaf or leaves, and plant the cutting in an equal-parts mixture of moistened peat moss and coarse sand or perlite. Plant three or four small-leaved cuttings together in a 3-inch pot, larger-leaved cuttings singly in 4-to 6-inch pots. Enclose the potted cutting (or group of cuttings) in a plastic bag or propagating case and stand it in bright filtered light at normal room temperature. Rooting should occur in three to four weeks. When renewed growth indicates that the new roots are well developed, remove the pot from the bag or case and begin to water sparingly (just enough to make the potting mixture barely moist), and to apply monthly doses of standard liquid fertilizer. About three months after the start of the propagation process, move each singly potted cutting into a slightly larger pot of the recommended potting mixture for adult plants, and treat it as a mature philodendron. Move the several cuttings of small-leaved plants to a larger pot whenever necessary, but keep them together. This helps to produce a bushy plant.
Propagation by tip cuttings is easy for P. scandens, with its small-size leaves. It is more difficult for some of the larger-leaved climbers. In propagating the climbing species other than P. scandens be particularly careful to protect cuttings from rough handling during the root-developing period. Damage to roots at this stage can be fatal to the plants.
Non-climbing species of philodendron are best raised from fresh seed. Sow seeds 4 inch deep in an appropriate rooting mixture in the spring, and keep the containers at a temperature of 80°-85°F. When the seedlings are 2 inches high, pot them up individually in 2- or 3-inch pots of the recommended potting mixture, and treat them in exactly the same way as mature plants.
Special points As indicated above, most climbing species of philodendron are usually tied to a stake or to several thin sticks inserted into the potting mixture for support. These plants are more attractive however, if, instead of being tied to the supportive structure, they can be made to cling to it with their aerial roots. For this to happen they must be given a moist surface to cling to, since aerial roots will not grip dry wood. One way to achieve the desired effect is to tie sphagnum moss to a stake, building the moss up around the stake until it forms a 2- to 3-inch-thick covering over the full length of the stake above potting-mixture level. Alternatively, nail a piece of rough-textured cork-bark to the stake. The moss or the bark must then be sprayed with water at least once a day. Some initial tying-in may be necessary until the aerial roots get a firm hold on the support. Be sure to use moss- or bark-covered stakes that are tall enough to accommodate the eventual total growth of the plants. It is difficult to add height to supports as plants continue to grow.