flotation method


Hippeastrum is a genus of about 70–75 species and 600+ hybrids and cultivars of bulbous plants in the family Amaryllidaceae, native to tropical and subtropical regions of the Americas from Argentina north to Mexico and the Caribbean. Some species are grown for their large showy flowers. These plants are popularly but erroneously known as Amaryllis, an African genus in the same family.


Hippeastrum is a popular bulb flower for indoor growing. The bulb is tender and should not be exposed to frost, but is otherwise easy to grow, with large rewards for small efforts, especially those that bloom inside during the winter months. The very large, decorative flowers can also be grown outside in temperate areas. Most hippeastrum bulbs are between 5–12 cm (2"–5") in diameter and produce two to seven long-lasting evergreen or deciduous leaves that are 30–90 cm (12"–36") long and 2.5–5 cm (1"–2") wide. The flower stem is erect, 30–75 cm (12"–30") tall, 2.5–5 cm (1"–2") in diameter and is hollow. Depending on the species, it bears two to fifteen large flowers, each of which is 13–20cm (5"–8") across with six brightly colored petals (three outer sepals and three inner petals) that may be similar in appearance or very different. Some species are epiphytic (H. calyptratum, H. aulicum, H.arboricola and some others) and need good air circulation around their roots. Research shows that respiration doubles with each 10 °C increase in temperature.

Hippeastrum species are used as food plants by the larvae of some Lepidoptera species including Hypercompe indecisa.


"Hippeastrum" is Greek for "horseman's star" (also known today as "knight's star") and was chosen in 1837 by the Honorable Reverend William Herbert, Dean of Manchester. No one is entirely sure why he picked this name although buds on the verge of opening do look something like a horse's ear and clearly the blossoms do resemble six-pointed stars. It seems likely however, as William Herbert was both a clergyman and something of an expert on early medieval history, that he chose the name because of the plants striking resemblance to the 'morning star', a medieval weapon used by horsemen. A version of the weapon was also called a 'holy water sprinkler', an ecclesiastical object the Dean would have been familiar with.

The first commercial breeders of hippeastra were Dutch growers who imported several species (see list at right) from Mexico and South America and began developing cultivars and hybrids from them in the 18th century; the first of these reached North America early in the 19th century. In 1946 two Dutch growers moved to the Union of South Africa and began cultivation there. Although most hippeastra come from the Dutch and South African sources, bulbs are now being developed in the United States, Japan, Israel, India, Brazil and Australia. The double flowers from Japan are particularly beautiful.

Flower characteristics

In general only a large bulb will put up more than one flower scape or spike but this depends on the cultivar itself, some smaller bulbs have two while some larger bulbs make only one. A bulb must produce at least four large, healthy leaves in the summer growing season before it can send up a scape the following year. Some bulbs put up two flower scapes at the same time or they may wait several weeks between blooms and sometimes the second scape will have only two or three flowers rather than the usual four. Dutch bulbs usually produce flowers first, then, after it has finished blooming, the plant will begin growing leaves. Bulbs from the South African growers usually put up a scape and leaves at the same time.

The flower colors include red, rose, pink, white, orange, yellow and pale green with variations on these including different colored stripes and edges on the petals. Some flowers have uniform colors or patterns on all six petals while others have more pronounced colors on the upper petals than on the lower ones.

There are five types: 1) single flower; 2) double flower; 3) miniature; 4) cybister; and 5) trumpet. Cybisters have extremely thin petals and are often described as spider-like. Trumpets, as the name suggests, have flared, tube-shaped flowers. Single, double and miniature bulbs are the ones typically sold by nurseries and other stores for the holidays in December and for Valentine's Day and Easter.

The lovely miniature "Papilio" (which is a species hippeastrum, meaning this is not a cultivar or hybrid but the actual plant that grows in the wild) has a unique color and pattern with broad rose-burgundy center stripes and striations on pale green on the upper petals and narrow stripes on the bottom three. "Papilio" has been crossed with both cybister and single flower hippeastra to produce hybrids with unusual striping.

Buying bulbs

Between 20–25 new hippeastrum cultivars come on the market every year and 10–15 are discontinued. Even though most stores and nurseries sell only a few of these, many others are for sale on the World Wide Web — as of December 2006 there were 194 different cultivars plus many species hippeastra for sale at online stores and auctions listed under both "hippeastrum" and "amaryllis." Newer and more exotic bulbs usually sell out the fastest.

Bulbs should be firm to the touch and greenish-white with thin brown outer layers like an onion. Nearly all bulbs for sale will be healthy but watch for and reject any that are soft, have blue or greenish mold, look decayed or appear to be extremely dried out or in a state of desiccation. Sometimes bulbs will already have a flower spike or leaves.

Growing hippeastra in pots

Hippeastra do well in either clay or plastic pots but those in clay pots may need to be watered more frequently than those in plastic. Pick a pot, with open drain holes, that is 10–15 cm (4–6") wider than the bulb. Soak the bottom of the bulb with the roots in warm (not hot) water — this will make them pliable and easier to spread out in the pot. Position the bulb so the top third is above the soil line. Use any good commercial potting soil and, if desired, top it off with a light covering of orchid mix or sphagnum moss as mulch.

Put the bulb where it will get some sun everyday and water it once. Care should be taken not to over-water: after the first watering do not water again until growth is visible or the soil has become bone dry, and then water sparingly. Too much water will cause the bulb and its roots to rot — at this stage the bulb is not capable of absorbing much water. Watering can be increased to weekly after an 20 cm (8") flower spake with bud or two 25 cm (10") leaves have appeared. Do not feed the bulb while it is blooming.

Most new hippeastra take between two weeks and three months to bloom after they have been potted. They may wait a few weeks or months and then rebloom, or they may be finished for the year. New bulbs usually produce a flower spike with four flowers but two or three flowers are not uncommon.

Some hippeastra grow both very long leaves and stems that may bend or even break under the weight of the flowers. Stake these with a wire plant support or by inserting a thin bamboo stick or dowel in the soil next to the bulb and then tying it loosely to the stem with wire ties or string. After blooming remove the flowers and allow the stem to die back until it turns yellow and sags, then cut it to within 5 cm (2") of the bulb. Keep the plant indoors in a sunny location until the time comes to move it outside for summer.

Summer care

In most parts of the continental U.S., bulbs can be moved outside by or before the end of May. Remember this is a semi-tropical plant that needs an extended growing season and there is not enough light in the average home for them to do well. Bulbs do need some sun during the day but their leaves may burn if they are subjected to prolonged periods of hot afternoon sun during summer. Water regularly and feed every other week with a general houseplant water-soluble fertilizer — or use a granulated fertilizer when repotting in the fall. A hot weekend with no water will not harm the bulb, but allowing it to sit in wet soil for several weeks will probably cause the bulb and its roots to rot; this condition also makes it more vulnerable to parasites and disease (see section below on fungal infections).

If desired, pots with bulbs can be buried in the garden for less maintenance and watering; in this case they also look more "natural" in the garden setting but they will have to be dug up in the fall. Hippeastrum roots do need oxygen (many species are epyphitic) when potting or planting make sure sphagnum moss does not go deeper than 1 cm below the bulb, use a granulated mixture (starting with the smaller granules and ending with the biggest — either perlite, pouzzolane, akadama or clay balls) in the root area to keep a good level of gas exchange and protect your plant from root rot.

Fall (Autumn) care

Except in very hot climates, cut back on watering in September — this is done to prevent rot as the bulb enters its resting period and no longer requires regular watering. If it continues to rain then move the bulb inside or to a covered porch. Otherwise, bulbs can be left outside in the sun until the night temperature reaches about 10 °C (50 F). Bulbs can survive a light frost, but not a heavy freeze. Begin the inspection/repotting phase in October or early November (depending on location and temperature): remove the top 5–7 cm (2–3") of soil and pull the bulb up. Inspect the roots for signs of parasites, disease or rot (note: healthy roots are white and slightly fuzzy). If the bulb and its roots look healthy, then put it back in its pot and replace the soil removed with new soil. Replace all soil every other year. If desired add 5 cc (1 teaspoon) of granulated fertilizer to the pot before replacing the bulb — in which case do not feed it during the summer (see above). Cut off any yellow or dead leaves.

Hippeastra produce more flowers when they are pot-bound and not putting their energy into growing new roots so many can be left in the same planter year after year; others may require a larger pot after a couple of years. Bulbs may produce offsets or daughter bulbs. These can be left with the mother plant until they reach blooming size and then removed and planted on their own.

There is a misconception that hippeastra need a period of total darkness before they will bloom again. This is not true, what they need is a rest period in a room with average light where the temperature is between 7–16 °C (45–60 F). This confusion no doubt comes about because two other popular plants sold during the winter holidays, Christmas cactus and Poinsettia, do require exact periods of light and complete darkness to set buds.

Most hippeastra need a rest period with light monthly watering of at least six weeks although others may require as long as three or four months. Often the plant will send up a flower spike or leaves when it is ready to resume growing in which case put it in a sunny window and water it once. A bulb that has not begun growing on its own after the rest period can be brought out and watered once. Usually the warmer temperature, sunlight and water will prompt it to begin growing again.

Growing hippeastra outdoors

Between 85–90% of all hippeastra are grown for indoor culture but they also make fine plants for outdoors in warmer climates. They should be grown in hardiness zone 8 and up, and should be planted where they get some sun every day; too much sun will cause the leaves to burn, however. Most hippeastra readily naturalize and over the years produce beds of lovely flowers. Some are evergreen and will not lose their leaves during winter while the leaves of others are deciduous and will die back until spring.

Growing hippeastra in water

There are special vases designed to hold hippeastra that are similar to those used to "force" hyacinths. Otherwise, it should be placed in a jar or vase that is slightly larger than the bulb. First soak the roots in room temperature water to make them pliable. Then fill the bottle about half way with rock chips. Carefully spread the roots in this while adding more rock chips until the roots and the bottom two-thirds of the bulb are completely covered. Add water up to the base of the bulb (and no further) and keep it watered at that level. Pour out all the water every other week and replace with new. Mixing in 15 cc (1 tablespoon) of activated carbon (charcoal) with the rock chips will help prevent the growth of algae. Bulbs grown this way will eventually need to be discarded.

Fungal infections and parasites

To avoid fungus problems (Stagonospora curtsii or "red blotch") the upper 2 cm (1") of the soil should remain dry. Stagonospora will create red spots on the leaves or flowers that look burnt or scorched. This distorts the shape of the leaves and results in red spots on the bulbs that cause them to rot. The spots form on leaves, flower stems and on the flower petals. The spots are small at first but often increase to form long blotches with definite margins. Leaves and flower stems attacked by this fungus are characteristically deformed or bent. Do not mistake an infestation of spider mites or bulb scale mite that can also result in red blotches. Injury from mite and insect damage appears as streaks, specks or irregular patterns lacking definite margins. If, however, an infection with red blotch has occurred, then bulbs can be treated with a hot water treatment — dig them up, shake off any dirt and then soak them for 30 minutes in water kept at constant temperatures of 40–46°C (104–114 F) for at least 30 minutes. Research has shown that red mite (a tarsonemid mite — Steneotarsonemus laticeps) infestation can be eliminated at daytime temperatures of 46° (114 F). In the wild, summer temperatures reach 40–50°C (104–122 F) in the shade; however, this is not true for all hippeastrum species, some being from cooler habitats. Since most hippeastrum owners don't live where daytime temperatures reach that high, a good rule to follow is to make sure bulbs are grown in optimal conditions — good soil, proper watering, regular feeding and adequate exposure to the sun — since these help the bulb to stay healthy and fight off infections and infestations on its own.

Germinating hippeastrum seeds

Like most liliaceous plants, hippeastra produce seed pods containing many winged seeds; seeds enclosed in a papery sheath. Hippeastrum seed can be difficult to germinate directly in soil, however they can be successfully germinated via the flotation method.

Once the seedpod has ripened and begun to split open, remove the seeds from the pod and let them dry for a few days. Most commercially sold hippeastrum have shiny black papery sheaths. If the sheaths are gently rubbed between two fingers, the actual seed can be felt as a hard inclusion slightly larger than a sesame seed. If no seed is felt, the seed may not be viable; the sheath can be opened with tweezers to confirm the presence of a seed without actually damaging it.

Fill a clear plastic container, for which a transparent lid is available, half full with water. Add activated charcoal to keep the water from going bad for 10–14 days. Hard tap water seems to work better than distilled or soft water. Sprinkle the sheathed seeds onto the surface of the water taking care that they do not overlap. The seeds will naturally gravitate towards each other, and it is acceptable for them to remain touching, however each seed should be floating directly on the water, and not resting on top of other seeds. Place the lid on the container, but do not seal it. The lid will help to maintain an elevated level of humidity, but if condensation on the inside of the container is observed, the lid should be opened further, or rotated so as to reduce the humidity.

The seeds need light to germinate, but cannot handle direct sunlight. A window sill that does not receive sunlight is perfect. After about two weeks, small white roots will be observed growing down from the bottom of the sheaths. In another week or so, small grasslike leaves will be observed pushing themselves out of the sheaths. It is acceptable, but usually unnecessary, to help the leaves escape the sheaths by using tweezers to slightly separate the papery layers.

Once the roots and leaves are both about 1 cm (1/2 "), the seedlings can be carefully removed from the water and placed, individually, in a seedling tray containing normal potting soil. Wet the soil well before transplanting, and use a toothpick to make holes into which individual roots will be placed. Gently pick up each seed by its leaf and settle its root into the soil. The remains of the sheath should be resting on the surface of the soil. After all the seeds are placed, water the tray gently but thoroughly to encourage the soil to adhere to the roots. Use a clear lid for the seedtray, or place the tray in a clear plastic bag, to continue to maintain an elevated but not saturated level of humidity until second leaves begin to appear.

At this point the seedlings may be hardened off by lowering the humidity and exposing them to open air. Given the usual time at which hippeastrum set seed, it will now be early summer, and the seedlings can be, in their tray, moved outdoors. They cannot handle direct sunlight, and the soil must be kept moist at all times for the first summer. In fall, watering may be reduced, but not, as for mature bulbs, entirely stopped. Continue growing the young bulbs outside in the summer, indoors in the winter. Provide a mild fertilizer, in summer only, beginning the second year. Do not transplant them until they become crowded; hippeastrum roots are important to the plant, but the roots of immature bulbs are not yet sturdy and can be easily damaged when transplanted. In three or four years the bulbs will have matured sufficiently to begin blooming. Since most commercially sold hippeastrum are hybrids, the young flowers are not likely to look like the parent.

External links


Ockenga, Starr. Amaryllis. Clarkson Potter, NY. c2002; 95p.

Read, Veronica A. Hippeastrum : the Gardener's Amaryllis. Timber Press, Portland OR. c2004; 296p.

Hippeastrum cultivars available as of December 2007

Cybister: Bogota* / Chico / Emerald / Exotic Star / La Paz / Lima / Night Star / Residence* / Rio Negro / Ruby Grace / Ruby Meyer / Sumatra / Sweet Lillian*

Papilio & Crosses: Giraffe / Jaguar / Papilio / Papillo Improved / San Antonio / Santa Fe

Trumpet: Amputo / Germa / Misty / Pink Floyd

Alfresco / Amalfi / Ambiance / Amigo / Amoretta / Amourette / Angelique / Antarctica* / Aphrodite / Appleblossom / Apricot Beauty

Baby Doll* / Baby Star / Barotse / Basuto / Benfica / Bingo* / Black Pearl / Blossom Peacock / Blushing Bride / Bolero / Bordeaux*

Calgary / Calimero / Candy Floss / Candy Stripe / Cantate / Cardinal* / Carmen* / Carnival / Charisma / Charmeur / Cherry Nymph* / Chianti / Christmas Gift / Christmas Star / Clown / Cocktail / Crystal Palace

Dancing Queen / Desire* / Double Dragon / Double Picotee / Double Queen / Double Record / Double Six

Elvas / Estella* / Europa / Exotica

Fairytale / Faro / Ferrari / Festival* / First Love / Flair / Flaming Peacock / Floris Hekker / Fortune / Furore

Gilmar* / Grand Cru / Grandeur / Green Goddess

Harvest* / Hercules / Hermitage / Honeymoon / Hope

Ice Queen* / Intokozi


Lady Jane / Lambada / Lemon-Lime / Liberty / Lilac / Lilac Wonder / Limona / Ludwig Dazzle

Macarena / Madrid* / Mambo* / Mary Lou / Matterhorn / Melusine / Merry Christmas / Milady / Minerva / Miracle / Monoco* / Mont Blanc / Monte Carlo* / Moonlight

Naughty Lady / Nymph

Olaf* / Olympus / Orange Sovereign

Pamela / Pasadena / Philadelphia / Piccolo / Picotee / Pink Blossom / Pink Diamond / Pink Impression / Pink Nymph / Pink Star / Pink Stripe* / Piquant / Pizzazz / Popov / Prelude / Princess Carnival / Promise

Queen of Hearts

Ragtime / Rainbow / Rapido / Razzle Dazzle / Red Charm / Red Knight* / Red Lion / Red Peacock / Red Pearl / Red Sensation / Rembrandt van Rijn* / Rilona / Roma* / Romance* / Rosetta / Royal Dutch / Royal Velvet

Salmon Master / Salmon Pearl / Samba* / San Remo / Santa Cruz / Santos / Showmaster / Snow White / Snowflake / Solomon / Star of Holland / Stargazer / Stars & Stripes / Summertime / Sunrise* / Supreme Garden / Susan / Sweet Surrender

Temptation* / Top Choice / Toronto / Trendsetter / Trentino / Twinkle Twinkle*

Unique / United Nations

Vegas / Vera / Vivaldi / Vlammenspel

Wedding Dance / White Dazzler / White Lady / White Nymph / White Peacock / Wonderland

Yellow Goddess


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