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14th Issue Vol. 2 No. 11 ISSN 2094-1765 November 2009

The Beauty of the True Bird of ParadiseBy Norberto R. Bautista

The true Bird of Paradise, orscientifically known asStrelitzia reginae is abeautiful tropical dwarfbanana-like plantindigenous to South Africa.Its common name is oftenassociated with theHeliconias, which is also arelative of this unique plant,including the travelers’palm. It is also popularlyknown as Crane Flower,due to its unusual form andcolor. This, together with itslong post-harvest life makesthis an very important cut-flower. Its scientific name

commemorates Charlotte Sophia of the Mecklenburg-Strelitz family, queen of King George III ofEngland. She is a patron of botany. The Bird of Paradise is commercially produced in countrieslike Hawaii, California, Florida, The Netherlands, France, Israel, and South Africa.

Because of its tropical beauty, it is the official flower of the city of Los Angeles, California, in theUnited States of America.

This herbaceous plant grows to about 2 meters (6½ ft) tall, with large, heavy, strong leaves 25-70cm (10-28 in) long and 10-30 cm (4-12 in) wide, produced on petioles up to 1 m (about 40 in)long. The leaves are evergreen and arranged in two ranks, making a fan-shaped crown. Theplant forms large clumps with many shoots arising from a dichotomously branched rhizomesystem. The flowers stand above the foliage at the tips of long stalks. The hard, beak-like sheathfrom which the flower emerges is termed the spathe. This is positioned perpendicular to the stem,which gives it the appearance of a bird's head and beak, thus given its common name. It makesa durable perch for holding the sunbirds which pollinate the flowers. The flowers, which emergeone at a time from the spathe, consist of three brilliant orange sepals and three purplish-bluepetals. Two of the blue petals are joined together to form an arrow-like nectary. When thesunbirds sit to drink the nectar, the petals open to cover their feet in pollen.

Cultural Requirements.

Light. Strelitzia reginae can be grown in full sun or semi-shaded, similar to bananas andheliconias. The more the plant is exposed to light, the more floriferous it is. However, checkappropriateness of lighting, as too much exposure to too much sunlight, especially summer mayscorch leaves.

Temperature. Bird of paradise flowers well in semi cool temperature range of 17-20 degreesCelsius; while at temperature higher than this, about 20-25 degrees Celsius tend to promote leaf

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production and inhibit flowering. It is ideal in semi cool areas in the Philippines like Tagaytay,Tanay, Baguio and Davao.

Watering. In their natural habitat, Strelitzia thrive near rivers, indicating their need for abundantsupply of water, although they can withstand some drought. Regular watering is a key incontinuous flower production. On the other hand, sufficient drainage is required to prevent thesoil from being too wet or water logged which may cause root rotting. The plant may also sufferfrom flooding for long periods.

Soil. The plants grows well inwell drained, fertile, humus rich,slightly acidic, loamy soil,though may also thrive isvarious soil types. For healthygrowth, use a potting mix of1:1:1 ratio of garden soil,compost and sand.

For container gardening,establish plants in 6-8 inch pots.Use a humus or compost richpotting mix for healthy growthand water regularly.

Fertilization. A completefertilizer high in phosphorus isneeded by the plant for healthy

growth. Fertilizers (example is 10-30-10 NPK) are applied at about 1 tsp per plant every 4months. Fertilizers should be applied monthly during the flowering season.

Control of Pest and Diseases. Strelitzia are susceptible to mealy bugs, scale insects, and rootrot. Regularly inspect plants for these insects. For repellant purposes, apply dilute solution ofsoapy water into the plants to discourage insects. For severe insect infestations, applyrecommended dosage rate of Parathion or Malathion insecticide.

Root rot is usually caused by a fungus, Thielaviopsis basicola and Rhizoctonia. To prevent this,provide ample drainage in soil or in pot and do not over-water. Apply a dilute fungicide drenchusing Dithane or Captan.

Propagation. In its native habitat, the plant is reproduced through seeds through pollination bysunbirds. However, since there birds are not present here in the Philippines, growers maypollinated them artificially to produce seeds through division of rhizomes or separation of singlerooted shoots to yield true to type plants.

If pollination is successful, 60-80 orange fuss covered seeds are produced, contained in a seedpod. Seeds has very hard seed coat and thus needs special treatment to overcome seeddormancy. Soaking seeds in concentrated sulfuric acid for 5 minutes or hot water treatment for30 minutes tend to treat this problem, though there are other techniques like prolonged soaking ofseeds in a basin of water, wherein water is replaced everyday is also applicable.

For rhizome divisions and single rooted shoots, use sterilized cutting or pruning instruments toprevent transfer of viral, fungal and bacterial diseases. Wash cutting tools in soap and water, andwipe with 70% isopropyl or ethyl alcohol. For rhizomes, each cut section should contain onelateral bud or “eye”. Cutting is usually done after flowering. It is recommended to remove first thesoil around the base of the plant, cut the crown into several divisions, dust the cut-surface withfungicide and let the would air-dry for a day in a shaded area. Then they are planted in soil or in

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a pot. A plant tissue culture technique has already been made to micro-propagate Strelitzia inlarge quantities.

Special Uses. Bird of Paradise flowers is used as a cut-flower for tropical flower arrangements,in ikebana flower arrangements and also mass-propagated for landscaping purposes.

Landscaping with Mussaenda Hybrids

The Mussaendas are attractiveadditions to open space landscapingspecially along roadsides, parks andparking spaces. With their colorfulmodified leaves of bright reds, pinksand whites, they provide accents andlife to dull monotonous greens in thegarden. What’s nice with them is thatthey bloom almost all-year round,except from January to March whenthey are less floriferous.

Mussaendas are tropical shrubs orsub-shrub (usually found growingbesides very large trees), and havean average height of about 10 feettall, though they can be trained as a

single specimen of 5 feet on ground or less than 3 feet in containers. Each flower is composed ofan inconspicuous small tubular five-petalled corolla in orangy-yellow and five greatly enlargedsepals (bracts). It is really these showy corymbs of white, off-white, pink or bright red enlargedleaf-like sepals that contrast beautifully against their dark green elliptic to ovate leaves.

Collectively known as Doñas, as they werenamed after the First Ladies of formerPhilippine presidents, Mussaendas arecultivated throughout the country. Themussaenda hybrids are considered acentennial breakthrough in PhilippineHorticulture, as one of the parent plants areindigenously Filipino. They are also very muchsought after in other tropical countries.

The plant is also known in other names likeTropical Dogwood, Virgin Tree and KahoyDalaga. It belongs to the plant familyRubiaceae, which also includes the commonSantan.

The development of the mussaenda hybridsgained momentum when a white mutant of thespecies Mussaenda. philippica was discoveredin Mt. Makiling, UP Los Baños in 1915. Thisspecies was named ‘Doña Aurora’ in 1938 inhonor of the wife of the late President ManuelL. Quezon. The late Dr. Dioscoro L. Umali,

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plant breeder and former Dean of theUP College of Agriculture, initiated thedevelopment of the hybrids in 1948using Mussaenda erythrophylla, aspecies native to India and with singlered petaloid and ‘Doña Aurora’ asparents. Continuous crossing andbackcrossing resulted into the presentcolorful hybrids of Mussaendas thatdiffer in the number of petaloidsdepending on the parents used.

Naming of the hybrids after thePhilippine First Ladies has become atradition. Though in 1986, some hybridswere given Filipino names like ‘Diwata,’‘Paraluman,’ ‘Lakambini,’ and ‘MariaClara.’

Other named hybrids includes M.‘Corazon C. Aquino’, M. ‘Doña Amelita’,M. ‘Gining Imelda’, M. ‘Doña Alicia’, M.‘Doña Esperanza’, M. ‘Doña Hilaria’, M.‘Doña Luz’, M. ‘Doña Pacencia’, M.‘Doña Trining’, and M. ‘Queen Sirikit’.

One hybrid plant was namedMussaenda ‘Gloria Macapagal-Arroyo’after our Philippine President and was

presented to her as a gift during their wedding anniversary. It was a cross between ‘DoñaEvangelina’ which has full, deep red petaloids as the female parent and ‘Doña Aurora’ (the firstMussaenda to be named after a First Lady), which has full, white petaloids as the male parent.

The hybrid befits our President since she is the daughter of a former First Lady after whom thefemale parent was named. It has also the smallest petaloids among the hybrids. Both mother anddaughter Mussaendas are very hard to propagate. On the other hand, the male parent is the mostpopular and well known among the Mussaendas. Mussaenda ‘Gloria Macapagal-Arroyo’ isofficially registered with the National Seed Industry Council of the Department of Agriculture.

Usage: White Mussaenda or Virgin Tree as commonly known can be grown as ornamental inparks and public gardens or along roadsides, byways and highways. Use in landscaping, thisplant serves well as a decorative specimen with its showy blooms and would fit beautifully inhome gardens too! Attractive to butterflies, bees, hummingbirds and insect pollinators as a nectarplant.

Cultural Requirements:

Light. Mussaendas are grown on full sun, however, the plant can tolerate semi-shadedconditions. The plant tend to be more floriferous with strong branches when exposed to morelight compared those in the semi-shade. However, the plant would prefer filtered mid-day sun inhot climates to prevent scorching of leaves.

Watering. The plant prefers regular watering, however, it should never be over-watered, or elsethe roots will rot. The plant is also sensitive to prolonged flooding.

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Soil and Potting Technique. The plant prefers a deep well-drained loamy soil for optimumgrowth. Some plants can be planted in large clay pots and maybe trained to substitute for theChristmas poinsettia due to its bright red, pink or white flowers.

Fertilization. For optimum growth, the plant needs regular fertilization by mixing about 1teaspoon of complete fertilizer 14-14-14 on the soil every month for potted plants. For largetrees, application of about 200 grams of complete fertilizer before and after the rainy season issufficient. Organic fertilizers can also be an option to synthetic fertilizers.

Controlling Pest and Diseases. Mussaendas does not have known serious insect or diseaseproblems however, growers need to watch out for spider mites and white flies infestations onindoor plants. This can be remedied by spraying a dilute soap solution on the whole plant as ainsect repellant. Avoid soil from being water-lagged to prevent fungal and bacterial diseases inthe roots.

Propagation. Mussaendas can be propagated from softwood or semi-hardwood cuttings andvery rarely from seeds. Marcotting technique is usually practiced or placing cuttings in mistingbeds or the lower tip is applied first with a rooting hormone before inserted into the soil.

Other Special Requirements. The shrub needs regular yearly pruning as the branches becomesleaf-heavy and may tend to bend and break during heavy rains, strong wind or during typhoons. Itis recommended to prune plants after blooming to get a bushy plant, though the lower stems tendto become bare however much you prune.

GROWING COELOGYNE ORCHIDS

Coelogyne orchids are oneof the most important orchidgroup, with approximately150 species distributedthroughout the southeastAsia area, China and thePhilippines . It is a groupwhich includes a number ofhorticulturally importantspecies that have been ingreat demand by orchidcollectors since theirintroduction in the last partof the 1800s. It alsoincludes some considerablenumber of botanical typeplants which are seldomfound in collections.Coelogyne orchids arepopular in collections due totheir mostly fragrant, freeflowering, and showyinflorescences.

Inflorescence of Coelogyne cummingii

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The orchid genus was found by Dr.Lindley in 1825, with the well-knownhorticultural species C. cristata as thetype specimen. The generic nameCoelogyne was suggested by theprominent depression in the stigmaand was derived from the Greekkailos, "hollow," and gyne, "a female."Plants of this group are stemless,characterized by tufted, crowdedpseudo-bulbs with two or threepapery leaves. The flowers are inracemes, mostly pendent, medium-sized, usually of delicate white,yellowish, and greenish color, oftensuffused with brown. The lip is three-lobed with erect lateral lobes.

Coelogyne cristata

Many species are very large epiphytic (occasionally lithophytes) plants which have quite showy,often fragrant flowers. They have quite large flattened pseudobulbs with one to two quite large,leathery leaves which are plicate. The pseudobulbs are often well spaced on a rather long,creeping rhizome so they are often best grown in a large basket or slab so they can roam aroundeasily.

Most of the Philippine members ofthe genus, of which there areabout 20, are usually smallflowered plants with greenish andyellowish flowers. There are twospecies, however, C. asperata andC. merrillii which produce flowersof substantial size and prove ofinterest to some collectors. C.asperata is indigenous to theSamar, Mindanao and Negros, aswell as in Borneo, Sumatra andNew Guinea . This is a large plantthat often grows three to four feettall and has flowers 11/2 to twoinches across. It is native to thehot, low coastal regions. C.merrillii, on the other hand, is amountain species and is found atan elevation of from two thousandto seven thousand feet. Thisspecies was named in honor of Dr.Merrill, the distinguished botanist,who has contributed extensively tothe study of the Philippine flora.

Coelogyne pandurata is one ofthe most attractive and popularspecies.

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Coelogyne marmorata is representative of a number of similar native Coelogynes, all of whichare indigenous to the mountains of northern Luzon and Benguet subprovince. Two other similarspecies, C. integerrima and C. chloroptera, also have shiny yellow green bulbs and sprays of

from five to ten light greenflowers.

C. marmorata and C.merrillii are usually foundgrowing on the moss-covered trees of the coolhumid areas of themountain regions and,therefore, cannot be grownsuccessfully in the hotclimate of Manila . Forhobbyists, some of thewarm growing species arerecommended for warmlowland temperature, whilethe cool growing speciesare recommended for coolupland temperature.

How to Grow this Plant.

Light. Coelogyne grow inabout 60% sunlight orbrighter, and needs to beprotected from direct heat ofthe sun.

Coelogyne lactea.

Temperature. Most Coelogyne species are cool growing, and growers may find it difficult toacclimatize plants in the lowland. however, there are also some species which are warm growingor have adjusted to the lowland condition and can therefore be grown in the warm lowlandcondition.

Potting Techniques. Coelogyne could be planted either in plastic or clay pots, and the planthave to be properly stalked or anchored in the center of the pot using GI or copper wires. Theplant must also be tied properly into the wire stalk to prevent it from moving during watering.Stalking is very important because insufficiently stalked plants will fail to root. A matured plant canbe divided into individual plants with 3-4 pseudobulbs. Sterilized pruning shear by washing insoap and water and wiping with 70% ethyl alcohol when dividing plants to prevent virus infection.The wound needs to be sealed with a fungicides paste to prevent entry of fungal diseases into thewound. Use combination of charcoal, broken clay pots, cracked limestone, and coconut huskchips as potting medium.

Water. Water plants moderately, about once every 3 days. Keep the growing area humid byproviding companion plants or wetting the surrounding areas and companion plants. Do not overwater or else the plant will rot. Ventilation or wind movement is very important in drying the plant.Allow air movement in the nursery or garden and provide enough space between plants.

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Fertilization. Fertilize plants with the usual dose of orchid foliar fertilizer spray, about 1 teaspoonper gallon of water, and spray it on the plant once a week, usually after watering.

Pest and Disease Management. Regularly check plants for insect pests or diseases. Plantsmaybe attacked by sucking insects like aphids, scales, mealy bugs or mites. For preventivetreatment, spray plants with dilute Perla soap solution to once a week, maybe together with thefertilizer. However, for insect pest infestation, spray plants with Lannate or Sevin insecticideswith formulation based on the label. For fungal diseases, do not overwater plants. During rainyseason, spray plants with Dithane or Captan fungicides as a prophylactic against fungal rots.Allow air movement, and always remove all dead or decaying plant parts from the plant.

Propagation. Coelogyne could be propagated through division of pseudobulbs. Care needs tobe observed in dividing plants, especially using only sterilized pruning shears by washing themfirst in soap and water and wiping with 70% ethyl alcohol. Plants are then divided into plants with3-4 pseudobulbs each and mounted on clay pots with charcoal. However, the fastest andefficient way of propagation is through seed culture technology in the laboratory. Flowers ofselected plants are pollinated, and their seed capsule are allowed to mature. Coelogyne seedcapsules mature in about 3 months. They usually contain thousands seeds. The seeds are thensown in the laboratory in a glass vessel with an artificial nutrient medium and seeds willgerminate in one month’s time. Seedlings will be ready to be planted in the nursery after 8months.

GROWING FIRE ORCHIDS

The fiery Renanthera philippinensis is a true eye-catcher in a garden of greens.

Fire Orchids or Renantheras are beautiful and highly collectable plants because of their intensered flowers. Renanthera species are used as parent plants in breeding today's bright redconventional and inter-generic vandaceous hybrids. They are ideal orchids used as accent plants

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in garden shows. They are medium size to tall plants, thus, they require stakes to support theirlong stems.

The genus Renanthera was named by JuanLoereiro in 1790 in the Flora Cochinchinensis,and the generic name came from the Latin word"ren" meaning kidney and the Greek word"anthera" or anther. It refers to the kidney-shaped anther of species. Renanthera coccineaLour. was the type species used for this brightlycolored genus. Worldwide, the genus has about15 species, mostly found in China, India,Thailand, Peninsular Malaysia, Vietnam, Laos,Indonesia, Borneo, New Guinea and thePhilippines. There are four species found in ourcountry, 3 of them are endemic, namely R.monachica, R. philippinensis, and R. storiei,while one species, R. matutina is indigenous.They are one of the most sought after Philippineorchid species locally and abroad. There arealso a lot of red flowered vanda hybrids or inter-generic crosses which has our Renantheraspecies bloodline.

A hybrid, Renanthera philippinensis x Azimah. Note thecolor contribution of the red species to this hybrid.

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These plants are usually epiphytes, however, there are occasions that some plants are found toadapt to a terrestrial habit, wherein some plants start their life as a soil growing orchid, and itsstem gradually climbs up the trunk of a tree and becomes an epiphyte. Renantheras has 2 basicgroups: one group has short stems like that of a Vanda, while another group is vine-like and withelongated stems, which may reach about 5-6 meters in height. Renantheras are closely related tothe Vanda and Arachnis orchids.

Most Renantheras have fiery red flowers, usually with shades of orange, thus given the commonname fire orchid.Cultural Requirements:

Light. Matured Fire Orchids grow in 75% light, and needs to be protected from intense heat andlight at noontime to prevent leaf scorching.

Potting Techniques. Fire Orchids can be planted in the soil enriched with animal manure andmulched with wood shavings or coconut husks. Some growers plant them in 1 foot diameter claypots with gravel + charcoal as potting material. Plants are often staked with bamboo or thick wireto keep stem upright. Secure stem on the stake by tying them properly using plastic coated wire.For epiphytic types, they can be mounted on wood branches.

Water. Water plants regularly, specially during summer. Allow wind movement to dry plantsbetween watering and to prevent fungal diseases

Flowering. Plants flower when mature, and when well exposed to light, and well fertilized andwatered. These plants produces fantastic bright red arching inflorescence.

Fertilization. Spray dilute orchid foliar fertilizers with trace elements once a week, usually afterwatering them in the morning for healthy and vigorous growth.

Pest & Disease Management. Fire orchids can be attacked by weevils or sucking insects likemites, thrips or aphids. For small plant population, weevil beetles can be handpicked in the nightas they are nocturnal insects. For serious insect infestations, spray Lannate or Sevin insecticideonce and check for reoccurrence. Fungal diseases usually arise during rainy season. Allowproper spacing between plants and ventilation. For fungal diseases, apply fungicides like Captan,Ridomil or Bavistin as a spray on the whole plant and drench on the potting medium. Visit plantsregularly, as pest and diseases can wipe out your collection.

Propagation. Conventionally, Fire Orchids could be propagated through top cuttings, similar inpropagating Vanda. Cut the top shoot segments with 3 roots using sterile pruning shears. Sealwounds on mother plant and on the top cut segment using fungicide paste, then mount on claypots with wire or bamboo stake. The fastest and efficient way of propagation is through seedculture technology in the laboratory. Flowers of selected plants can be pollinated, and their seedcapsule are allowed to mature. Renanthera seed capsules mature in about 5 months (but alsodepends on species and hybrids, including the season). They usually contain thousands ofseeds! Using orchid seed technology, the seeds are then sown in the laboratory in a glass vesselwith an artificial nutrient medium. The seeds germinate in a month’s time and will become hardyseedlings in a years time. Then, they can be out-planted in the nursery where they mature from 2to 3 years. The Singaporeans are the ones extensively using Renantheras in their vandaceousorchid breeding program.

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GROWING ONCIDIUM ORCHIDSby Norberto Bautista

The Oncidiums or Dancing Lady Orchids are one of the popular epiphytic sympodial orchid grownin the Philippines, due to its ease of growing and its long lasting sprays of flowers. Their namewas derived from the appearance of their flowers, similar to a Spanish dancer. They were one ofthe very first of the tropical epiphytic orchids introduced into European cultivation. They can begrown in the garden, mostly thriving in neglect. Oncidiums, together with Odontoglossums andother related types (like Brassia, Wilsonara, Cochlioda, Miltonia, Colmanara, Vuylstekeara, andBurrageara) comprise a very large orchid alliance, which offers a wide range of color patterns andcultural flexibility.

Oncidiums are introduced orchids, which are found exclusively in the Western Hemisphere. Itsnative habitat ranges from Florida and Mexico through Central and South America, from sea levelto 12,000 ft. . The Oncidium alliance is composed of approximately 70 genera, and there areapproximately 1,200 species. There are also thousands of hybrids. The most common flowercolors are combinations of yellow and brown, although lavender, red and white are colorsinfrequently seen in the genus. These colors are consistent with Hymanoptera (bee and wasp)pollinated flowers. Clear red coloration is infrequent as most bees are blind to red, the few flowersof red color often reflecting ultraviolet rays which the bees can perceive. The individual flowers ofmany species are not large, but this is more than compensated for in most species by the greatnumber of flowers produced on long, often branching flower spikes, producing a “shower of gold”effect. The majority of plants have rather prominent pseudobulbs and strap-shaped, somewhat

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Oncidiums or Dancing Lady Orchids have typical appearance of “Dancing ballerinas withwide yellow skirts and brown heads and arms.

thin leaves. Roots of most oncidinae are fine and numerous. Most species are epiphytes, growingon forest trees.

Cultural RequirementsLight. Oncidiums prefer bright light, similar to Cattleyas (ranging from 1500 to 4000 foot-candles)provided they are protected from too much heat. To check if your plants is receiving the right lightintensity, reddish green leaves indicates too much light, while dark green leaves indicates notenough light. Insufficient light usually produces spindly growth, thin pseudobulbs, and dark greenleaves. They may even fail to flower. Overexposure to sun produces plant with stunted growth,yellowing to almost bleached appearance.

Water. The rate of watering depends on location, wind movement, and light intensity. Oncidiumshave pseudobulbs, its water storing organ, thus, they can tolerate some degree of drying. Waterplants every 3-5 days. Water only when the potting media is dry. This can checked by dippingyour thumb into the potting mix in the pot. When watering, water the whole plant until it is drippingwet, then let it moderately dry before the next watering. Plants are usually watered early morningor late in the afternoon.

If the pseudobulbs are becoming shriveled, the plant is not getting enough water. Over-wateringwill also cause this symptom. Too much water will rot the roots, therefore preventing the plantfrom getting any water.

Humidity. Humidity can be increased by wetting the surrounding area around the orchid orproviding companion plants like ferns, bromeliads, and other foliage plants. Humidity for pottedplants can be increased around the plant by placing the pot on an inverted saucer in a baking pan

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filled with pebbles, rock and water. Keep water level below top of pebbles so that plant will nothave "wet feet" from sitting in water. Morning misting of foliage is also helpful.

Fertilization. Oncidiums are moderate feeders, and they respond very well to fertilization.Fertilize during active growth, and during sunny days. Use foliar fertilizers for orchids (with traceelements and follow the recommended dilution rate in the label). Oncidiums are usually fertilizedonce per week. Use balanced growing fertilizers with high Nitrogen (N) for seedlings and high inPotassium (K) or blooming fertilizers for matured plants. Wet plants with water first beforespraying dilute solutions of fertilizers. A small amount of organic fertilizer like decomposedchicken manure, or control release / slow release fertilizers can be added to the pot for addednutrients.

Ventilation or wind movement is very important in drying excess water on the plant. Plants needsto be kept dry a few hours after watering. Water soaked plants tend to rot. Use an industrial orelectric fan to dry large number of plants if wind movement is not available.

Flowering. Plants flower when mature, and when well exposed to light, well fertilized andwatered. Oncidium hybrids are usually free-flowering. Oncidium orchids produces sprays ofyellow, brownish or white flowers.

Pest and Diseases Control. These plants are susceptible to rotting, thus, keep plants dry asmuch as possible. Limiting the watering to once every 3 days will solve this problem. Applyfungicides like Captan, Ridomil or Bavistin as a propylactic during the rainy season or when thereis fungal disease. Apply Lannate or Sevin only when there is serious insect infestations. Alwayscheck root system and potting mix for signs of rotting. Repot and replace potting mediumimmediately when roots are rotting, specially during the onset of the rainy season. As much aspossible, use as minimal charcoal.

Potting Techniques. Oncidiums could be planted either in plastic or clay pots, and the planthave to be properly stalked or anchored in the center of thepot using GI or copper wires. Since these plants are either small or medium sized, pot sizes of 3-5 inches diameter or slightly bigger are used. The plant must also be tied properly into the wirestalk to prevent it from moving during watering. Stalking is very important because insufficientlystalked plants will fail to root.

Oncidium are usually repotted at least every year to 18 months. As a general rule, repot themwhen the new shoot is two to three inches tall or when new roots appear. Repot when the planthas overgrown their pot or there is signs of root / stem rotting or decay. All the old mix should beremoved from the roots and any dead roots should be removed. If dividing, keep the divisions inclumps of three to five mature bulbs. Use charcoal as potting medium with a thin top dressing ofchopped coconut husk or tree fern roots. This orchid can also be mounted on dead wood, or ontree fern slabs. Most Oncidium are epiphytes in nature, meaning they grow on tree trunks andlimbs.

Propagation. Oncidiums can be asexually propagated. A matured plant can be divided intoindividual plants with 3-4 pseudobulbs. The plants need to be cut using a sterilized pruning shear(dipped in Chlorox solution every time a new plant is to be cut or washed in soap and water) andswabbed with 70% ethyl alcohol to prevent spreading plant viruses. The wound needs to besealed with a fungicides paste (a teaspoon of water added in 2 teaspoon fungicide powder) toprevent entry of fungal diseases into the wound.

The fastest and efficient way of propagation is through seed culture technology in the laboratory.Flowers of selected plants are pollinated, and their seed capsule are allowed to mature. Oncidiumseed capsules mature in about 3 months (but also depends on species and hybrids). Sterility insome crosses are sometimes observed! Once the seed capsules are mature, they can beharvested and brought to an orchid lab for seed sowing. The seeds are then sown in the

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The Urban Gardener is an official electronic publication (in PDF Format) of the Plant BiotechnologyProject, Research & Development Center, Rizal Technological University, Boni Avenue, MandaluyongCity, Philippines. It is published monthly. For more information, please inquire thru email:rdc_rtu@yahoo.com or plantbiotech_rtu@yahoo.com and landline (+632) 534-8267 Local 135 or Fax(+632) 534-9710.

All articles in this month’s issue was written and edited by N.R. Bautista © November 2009

The Plant Biotechnology Project Committee is composed of: Alexander B. Quilang, Norberto R. Bautista,Jovita A. Anit & Carnette C. Pulma.

laboratory in a glass vessel with an artificial nutrient medium, under aseptic conditions. Seedsusually germinate within a month, and will be ready for greenhouse establishment in less than ayear’s time. They are usually out-planted in the nursery, where they mature after 2-3 years.

CRAZY ABOUT PUMPKINS AND GOARDS ATPUENTESPINA / WALING ORCHIDS

New varieties of goards andpumpkins for the Halloween aredisplayed at the Puentespina Orchidstore in Manila Seedling Bank.

Children enjoyed the trip. These colorfulpumpkins’ hard skins make the fruits canlast 2-3 months as table decorations… goodfor All Saint’s Day , Christmas, and NewYear and the Lunar Chinese New Year…