As I write, strange spears are appearing from the soil in many areas of my garden. In a week or two these spears will burst into heads of large stunning flowers. Hippeastrums are a favourite plant of the warm climate gardener, with large flowering hybrids being most popularly grown.
The name Hippeastrum is Greek for ‘Knight Star’. These plants are sometimes referred to as Amaryllis by older gardeners, however this name is more correctly used for bulbs found in Southern Africa. Amaryllis generally prefer Mediterranean climates with dry summers, and thus do not prosper in summer rainfall areas.
Hippeastrums grow from large bulbs, 6 to 12 cm across which are rather like onions in appearance. 4 to 6 mid-green leaves are produced in two planes from each bulb. They are generally 30 to 90 cm long and 2.5 to 5 cm wide.
Each flower consists of 3 petals and 3 sepals, jointly referred to as tepals. They may be 12 to 25 cm across on stems 30 to 70 cm high. They come in shades of red, rose, pink, salmon, orange, cream, white and pale green. They may be a solid colour or have a paler centre; stripes; reticulations; and varied shadings of these colours. They may be single or double; wide spreading or trumpet shaped; broad or narrow petalled; and miniature or large. Small or narrow petalled flowers can often look superb in the garden although they are often overlooked for their showier cousins.
The flowers tolerate the dry winds, heavy downpours, hot sun and rapidly rising temperatures. Spring in the tropics and subtropics is not the delicate mild season so typical in cooler climes. Instead, it is a tumultuous season and one of the most trying times for gardeners. Cool climate bulbs may flower (often for the first and last time) but may be burnt to a crisp by the heat or dry winds or bruised by hail or a spring storms. If the flower is damaged, there is another bud down below the flower, ready to take its place.
Hippeastrums do particularly well in areas with a summer dominant rainfall pattern, conditions which best suit their natural growth rhythms. They go into dormancy and defoliate during the dry winters and springs; flower in late spring just before the rains arrive; and the burst into leaf during the warm moist and humid summer and autumn months. Where I live in Queensland the bulbs come into flowers in late September and early October. As you drive around the suburbs, flowers can be spied in many front gardens. In older areas they form huge and spectacular clumps.
Hippeastrums are extremely hardy. I have seen large clumps in neglected gardens which cover many square metres and which have survived where many other plants, and the garden itself, have long disappeared. They thrive in full sun or light shade and in well drained soils. While plants will survive on virtually no rainfall for a year or two, they may not flower profusely. To encourage profuse flowering and growth, provide well mulched, organically enriched soils, and regular applications of fertilisers including ground rock minerals. Plants resent disturbance and will flower less profusely for a year or two following division or replanting.
Sourcing bulbs can be tricky. It is often easier to buy cold climate bulbs, than those that do well and thrive in warm climate. Each year dried bulbs are offered by garden centres and hardware stores. While many are beautiful, they may not be as vigorous as plants that have been grown in gardens for many years. Locating plants that grow well in your area is the best approach. Visit specialist nurseries and gardens during the flowering season and select plants based on appearance and vigour. Keep a look out, you may find friends or neighbours who have these plants growing in their gardens and will be happy to share them with you. The internet is also a great way to source bulbs which are readily sent in the mail while dormant.
The genus Hippeastrum has a broad distribution from Mexico, through Central America, the Caribbean and down through South America to Argentina. Brazil is the centre of distribution. The species are quite unique and often very different to the more popular hybrids with which most people are familiar. I am a great fan of species plants and always on the look-out for them. Some particular favourites of mine which I recommend include:
Hippeastrum papilo – has pale greeny white flowers with deep red veins which emanate from the centre of each tepal. This spectacular plant is endangered in the wild and deserves more widespread cultivation. In the wild it grows as an epiphyte in remnants of the Atlantic Forest of South Brazil.
Hippeastrum petiolatum – is a small plant with orange –red flowers and narrow leaves. In the wild this plant also grows as an epiphyte.
Hippeastrum puniceum – was once widely seen in Queensland gardens, but sadly is not commonly encountered these days. It’s a very hardy, vigorous and free flowering plant. The large flowers are carried on long stems and are orange with broad cream stripes down the centre of each tepal.
Hippeastrum reticulatum – has velvety, deep green leaves with a central silver stripe. The plant could be grown for the leaves alone. The stunning pale pink flowers are reticulated with rose veining.
Hippeastrum striatum – is a small plant with orange flowers which have a cream centre. This plant produces numerous bulbils and readily forms a clump.
Propagation is generally done by division. This is extremely easy. The plants grow virtually on top of the soil and the bulbs are large and visible. It is a simple matter to dig up these bulbs which readily separate. Division is best done during the winter to spring dormant season when the bulbs are leafless. When replanting, place bulbs at 300 to 500 mm centres. The widest part of the bulb is best located level with the surrounding soil.
Plants may also be grown from seed which is readily produced. Following flowering, pods will set on the plants. After 4 to 5 weeks they yellow and start to split. Shake out the papery black seeds. Spread them on top of some sterilised potting media and keep moist in a shady location. Young seedlings will soon appear. They are grass-like at first, and soon require dividing and repotting, before hardening off and planting out in the garden. Plants grown from seed produce flowers which are variable in appearance.
Commercially, a form of propagation known as ‘cuttage’ is widely used. Bulbs are cut vertically in quarters, each with a portion of the basal plate (the plate at the base of the bulb from which the roots emerge). Apply fungicide to the cut surfaces and plant so that the cut side is facing upwards and 1/3 of the basal plate is planted in the potting media. Small plants will soon from along the basal plate.
Hippeastrum flowers can be large and dramatic – particularly as thet are borne whilst the plants are leafless. When mass planted or allowed to grow into large clumps the flowers will dominate the garden area. Gardeners can get inspiration on using these plants in the garden from the ways tulips are planted in cool climates. They can be mass planted to create a massive sward of colour against a green backdrop; peppered in groups through other flowering plants with harmonious or complementary colours; rhythmically planted along paths or roadways; as a specimen planting to terminate a vista or act as a focal point;
Pure red or white Hippeastrum flowers can look dramatic against a green leaved backdrop. A gradation of pink flowers can add depth and interest to a planting. Consider developing a garden that reaches its peak at the time the Hippeastrum flowers. Complement bulbs with other flowering perennials and locate a table and chairs nearby. Now, throw a party against this backdrop – it will be memorable.
Grown in large pots and allowed to grow into large specimens, plants can be moved into prime spots in the garden when in full flower. Large shallow pots are particularly dramatic when used in displays. This is also a great ways to grow these plants in cooler areas, as the pots can be brought under shelter and kept warm and dry during the winter months.
Pests and Diseases
While Hippeastrums are hardy and generally pest free, like any plant, they do occasionally suffer from pest and diseases. Like most plants, this generally indicates suboptimal health – poor nutrition or an inappropriate location or microclimate. Before you reach for the fungicide and pesticide, look at ways to increase plant vigour by improving nutrition or relocating the plant to a better location.
Locusts will occasionally feed on leaves. A morning inspection of the garden when these insects are torpid allows you to readily catch them. Mealybugs can occasionally infest plants and reduce vigour. Ensuring plant nutritional needs are met, particularly calcium, magnesium, boron and silicon, can discourages both these pests. Apply these elements in a complete garden fertiliser.
Red Blotch (Stagospora curtisii) is a widespread foliar fungal infection. It shows up as sunken, elongated, reddish-orange areas which can deform leaves. It generally occurs early in the season when plants are shaded, cold and wet. It may only show up after an extremely wet and cold winter, but if it is a regular occurrence, the plants are best moved to a warmer, sunnier part of the garden and provided with improved nutrition. Foliar applications of fungicides may temporarily solve this problem, but can also drip down into the soil killing off valuable soil biology.
Hippeastrums are one of the showiest flowering bulbs in the world and thrive in warm climate gardens. These hardy bulbs require minimal maintenance, and continue to provide a floral display for many decades. With a little bit of thought they can be used a feature of the spring garden. Enjoy the floral displays in gardens in your area and then consider which colours and what planting locations will work best in your garden – then get planting and prepare for next year’s floral extravaganza.