Posted by: marinvit | January, 2010

World Of Orchid

In the World of Flowers, the Orchids are accounted as undisputed Champions. Their exclusive Beauty and variety of Color and Shapes enchants the Hearts of Men and Women as one. Some Orchids have tiny Inflorescence and others – sometimes grow to the diameter of a Plate.

In the Past, Orchid cultivation was a significantly expensive Hobby. However, today, Orchids are within the reach of everyone. if you grow House Plants , you can grow Orchids as well. Since the Orchid Flowers are durable and (some) may Flourish in harsh conditions.

The Orchid Family (Orchidaceae) is one of the biggest Families in the Plant World. you can find Representatives of the Family in a Variety of Habitats . From tropical Rain Forests to dry Desert Areas. From Ground Levels to Altitudes of 2000 Meters and more.

In tropical Rain Forests you can find mostly Epiphytic and Lithophytes (Orchids that grow on Tree Branches, Trunks and Rocks rather than out of the Ground) most of them are Species from the types : Phalacnopsis, Cattleya, Laelia, Epidendrum, Dendrobium.

in the cold Temperate Areas: you can find Terrestrial (orchids that grow on the Ground) Orchid types: Cymbidium, Paphiopedilum, Odontoglossum, Masdevallia and more.

Temperature Requirements

with Temperature requirements in Mind. You can classify most Orchids into Three main Groups:

1.Orchids from colder Areas, where the Minimal Temperature is 10 Degrees Celsius and the Maximal Temperature is 30 Degrees Celsius. some of the Orchid types that belong to this Group are : Cymbidium, Masdenallia, Paphiopedilum, MiltoniaS, Odontoglossum.

2.Orchids from Temperate Climate Areas.
where the Minimal Temperature is 13 Degrees Celsius. and the Maaximal Temperature 30 Degrees Celsius. some of the Orchid types that belong to this Group are : Oncidum, Brassavola, Cattleya, Dendrobium, Epidendron, Paphiopedilum (with striped Leaves) and Laelia.

3.Orchids from warm Climate Areas.
where the Minimal Temperature is 15 Degrees Celsius and the Maximal Temperature are 32 Degrees Celsius. some of the Orchid types that belong to this Group are : Phalaenopsis, Vanda, Ascocentrum.

Irrigation and Fertilization

In tropical Forests, The Epiphytic Orchids grow in conditions like frequent Rain, and high counts of Humidity. Therefore a Regime of Irrigation and Dehumidification which imitates the Original Habitat is the proper Regime for most cultivated tropical Orchid Flowers. the frequency of Irrigation depends
on the Measurement of the airing and the drainage of the ground.

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Posted by: marinvit | January, 2010

Orchid Growing

The orchid family is one of the largest and most varied in the plant kingdom. Some root in the soil, while others cling non-parasitically to the trunks of trees or rock cliffs. Some orchids require moderate shade and others thrive in full sunlight.

Additionally, some can withstand long periods of drought, while others require constant moisture. The key to successfully growing orchids is the proper choice of species and an understanding of the environment in which they grow naturally. The following are a few orchids recommended for a beginning grower.

Paphiopedilum species and hybrids (Lady’s Slippers) require relatively low light levels. Some need cool (45 to 55 degrees F) growing conditions while others do well at intermediate temperatures (55 to 65 degrees F). They are terrestrial and should be potted in a finer textured potting mix than epiphytes.

Coarse sand and peat make a good potting medium. Paphiopedilum will not tolerate drying but should not be kept in a soggy condition. These species are good candidates for growing under fluorescent lights.

Cymbidium species and hybrids require high light intensity and cool temperatures. These terrestrial orchids will not flower without low night temperatures (33 to 40 degrees F). The miniature species and hybrids are somewhat less demanding with regard to temperature and are the best candidates for indoor culture. A well-drained potting mixture is required for best results.

Cattleya species and hybrids are the most common commercial orchids. These orchids are epiphytic and require intermediate temperatures and high light intensity. They should be potted in a coarse, well-drained potting mix without much water-holding capacity. The species often have a stringent rest requirement between flowering cycles. Many hybrids are much less demanding and make good indoor plants.

Dendrobium species, especially Dendrobium phalaenopsis, are good candidates for indoor culture if large size is not a problem. D. phalaenopsis is an epiphyte requiring intermediate temperature and relatively high light intensity.

Most of the varieties will grow and flower well if given a four-week rest period as new growth matures. Watering should be reduced during this period but not stopped. Some varieties may flower without a rest period.

Phalaenopsis species and hybrids (moth orchids) are epiphytes requiring warm temperatures. They grow well under relatively low light intensities and are good plants to grow under fluorescent lights. These plants must have a very coarse potting medium that drains rapidly. They do not tolerate drying and must be watered frequently.

It is not uncommon for individual flowers to remain in good condition on the plant for two to three months. A well-maintained plant may flower up to 18 consecutive months.

Posted by: marinvit | December, 2009

Growing Orchiid (part 2)

Watering frequency depends on the medium in which they are potted. Most orchids cannot survive prolonged drought and should be watered often. However, some require a “dry season” of six to eight weeks during which watering is reduced but not stopped.

This “dry season” must occur immediately after maturation of the current season’s growth and is often necessary to initiate flowering. Nutrients must be provided in dilute concentrations when orchids are grown on inert media. Moderate air circulation is required for best growth. Be aware that many factors may prevent flowering in orchids.

Insufficient light is the most common reason. If there is too little light, the leaves become a deep, lush green. With too much light the leaves turn yellow-green. For proper flowering, the leaves should have only a slight yellow tint. Some orchids may not bloom if the nighttime and daytime temperatures are the same.

Consistently warm temperatures are good for vegetative growth, but may suppress flower development. A 10 to 15 degree reduction in the night temperature for two weeks in the fall or spring is needed to initiate flower development. Dry air may result in failure of flower buds to open and death of plants in extreme cases.

A relative humidity of 60 percent will alleviate the problem. Orchids are affected by many of the same pests and diseases as other houseplants. Insects such as mealybugs and aphids can be controlled with the proper insecticide. Good cultural practices and the purchase of healthy plants will reduce the chance of disease although most fungal and bacterial diseases may be controlled using commercially available fungicides and bactericides.

Posted by: marinvit | December, 2009

Growing Orchid

If you can’t get to Hawaii this winter, then why not bring Hawaii to you? Create a tropical paradise by growing orchids indoors.

Granted, care must be taken when growing orchids at home. However, they are no more difficult to grow than most other houseplants when their particular growth requirements are met. In fact, some orchids are as easy to grow as cacti.

Although there are more than 25,000 species growing in climates ranging from the arctic tundra to the tropical rain forest, the orchids most often cultivated are species from tropical climates. They are commonly grouped by cool, intermediate, and warm temperature requirements based on the plants’ optimum night requirements (45 to 50 degrees F, 55 to 65 degrees F, and above 65 degrees F, respectively).

The beginning grower should consider starting with established plants which should bloom within a year. Seedlings are less expensive but may take up to five years to flower. Natural species may be grown, but the hybrids are often more vigorous and less demanding in their cultural requirements.

Light is often a factor limiting the growth of orchids. Most orchids require relatively high light intensities and should be grown in an east or south window. However, a few will grow well under low intensity fluorescent lights.

Orchids vary in their water requirements. Many tropical orchids are epiphytes, growing on the side of trees, and will not do well if their roots stay wet. Epiphytes should be grown in a very porous potting medium such as coarse fir bark, lava rock, or coarse perlite. Terrestrial types rooted in soil require a well-drained, finer textured growth medium.

Posted by: marinvit | November, 2009

Orchid Flower

Orchidaceae are well known for the many structural variations in their flowers.

Some orchids have single flowers but most have a racemose inflorescence, sometimes with a large number of flowers. The flowering stem can be basal, that is produced from the base of the tuber, like in Cymbidium, apical, meaning it grows from the apex of the main stem, like in Cattleya, or axillary, from the leaf axil, as in Vanda.

As an apomorphy of the clade, orchid flowers are primitively zygomorphic (bilaterally symmetrical), although in some genera like Mormodes, Ludisia, Macodes this kind of symmetry may be difficult to notice.

The orchid flower, like most flowers of monocots has two whorls of sterile elements. The outer whorl has three sepals and the inner whorl has three petals. The sepals are usually very similar to the petals (and thus called tepals, 1), but may be completely distinct.

The upper medial petal, called the labellum or lip,  is always modified and enlarged. The inferior ovary (7) or the pedicel usually rotates 180 degrees, so that the labellum, goes on the lower part of the flower, thus becoming suitable to form a platform for pollinators.

This characteristic, called resupination occurs primitively in the family and is considered apomorphic (the torsion of the ovary is very evident from the picture). Some orchids have secondarily lost this resupination, e. g. Zygopetalum and Epidendrum secundum.

The normal form of the sepals can be found in Cattleya, where they form a triangle. In Paphiopedilum (Venus slippers) the lower two sepals are fused together into a synsepal, while the lip has taken the form of a slipper. In Masdevallia all the sepals are fused.

Orchid flowers with abnormal numbers of petals or lips are called peloric. Peloria is a genetic trait, but its expression is environmentally influenced and may appear random.

Orchid flowers primitively had three stamens, but this situation is now limited to the genus Neuwiedia. Apostasia and the Cypripedioideae have two stamens, the central one being sterile and reduced to a staminode. All of the other orchids, the clade called Monandria, retain only the central stamen, the others being reduced to staminodes (4). The filaments of the stamens are always adnate (fused) to the style to form cylindrical structure called the gynostemium or column (2). In the primitive Apostasioideae this fusion is only partial, in the Vanilloideae it is more deep, while in Orchidoideae and Epidendroideae it is total. The stigma (9) is very asymmetrical as all of its lobes are bent towards the centre of the flower and lay on the bottom of the column.

Pollen is released as single grains, like in most other plants, in the Apostasioideae, Cypripedioideae and Vanilloideae. In the other subfamilies, that comprise the great majority of orchids, the anther (3), carries and two pollinia.

A pollinium is a waxy mass of pollen grains held together by the glue-like alkaloid viscin, containing both cellulosic stands and mucopolysaccharides. Each pollinium is connected to a filament which can take the form of a caudicle, like in Dactylorhiza or Habenaria or a stipe, like in Vanda. Caudicles or stipes hold the pollinia to the viscidium, a sticky pad which sticks the pollinia to the body of pollinators.

At the upper edge of the stigma of single-anthered orchids, in front of the anther cap, there is the rostellum (5), a slender extension involved in the complex pollination mechanism.

As aforementioned, the ovary is always inferior (located behind the flower). It is three-carpelate and one or, more rarely, three-partitioned, with parietal placentation (axile in the Apostasioideae).

Posted by: marinvit | November, 2009

Growing Orchids Indoors

Potted orchids have become increasingly popular and common in stores.  If you want the plant to continue growing after bloom, and bloom again in future years, choosing the right ones is key.  Also important is the culture, which is a bit different from most other houseplants.

Epiphytic orchids

To begin with, orchids vary in their temperature requirements.  Choose those that fit your home environment in winter– warm-growing ones if it is consistently warm (68-75 degrees) or intermediate-growing if night temperatures are lower (60-65 degrees).  Very important for orchids of all types is high humidity and high light during winter, indirect light during summer.

If you buy an orchid, you may notice it is not growing in soil but rather in bark, a black fiber (roots from the osmunda fern), or similar material.  This is because most orchids are “epiphytic”, getting most their water and nutrients from the air through aerial roots.  These are often the white thick roots you see growing from the plant on the surface or even outside the pot, which should NOT be cut off!  Exceptions to the epiphytes are the few that grow in soil (terrestrial) or on rocks (lithophytic).

Many epiphytes have upright swollen stems called “pseudobulbs” which rise from a rooted horizontal stem.  They serve to store food and water.  Examples of these are popular genera such as Cattleya, Dendrobium, Epidendrum, Laelia, and Oncidium.

New pseudobulbs are formed along the horizontal stem, meaning growing is in a horizontal direction.  Such orchids are often called “sympodial”.  If these are planted in osmunda, you may need to water every 3 or 4 days.  Water more often if they are planted in bark.

Other epiphytes, such as Vanda and Phalaenopsis, don’t have pseudobulbs.  Their growth is upright along a single stem.  Aerial roots come from the stem, often from between the leaves.  These orchids are often called “monopodial”.  Since they don’t have storage structures either above or below ground, they often need water daily.

When checking for water, never let the orchids dry out completely.  Water well until water is running out the bottom of the pot.  But don’t let plants stand in water, as in a saucer.  I find it easier to water pots holding them over a sink or bucket.

Epiphytic orchids are quite sensitive to air pollution, water quality, and too much fertilizer.  If too little fertilizer, pseudobulbs may shrivel and leaves turn light green or yellow.  If leaves are dark green and floppy, and there are no flowers, this indicates too much fertilizer.  Blackened root tips indicates damage from too much fertilizer.

Softened water should not be used, as the salts will damage roots.  Most chlorinated city water sources can be used, although excess chlorine can also damage roots.  The best water to use is distilled water, pure spring water as you often find in stores, or even collected rain water.

Fertilizer varies mostly with type of growing medium, type of and amount of growth.  Plants actively growing, sending out new shoots, will need fertilizer.  If inactive or dormant, as in the rest period with some orchids, don’t fertilize.

Plants growing in osmunda need less fertilizer than those growing in bark.  Sympodial orchids, having the pseudobulb storage organs, need less fertilizer than monopodial ones.  Although most houseplant fertilizers will work, you may wish to get one specially formulated for orchids.  Follow label directions for the rate.  A general houseplant fertilizer, applied to plants in bloom or active growth, might be every two weeks for sympodial orchids in bark, every 4 weeks if in osmunda, and twice as often for  monopodial orchids.

Posted by: marinvit | October, 2009

Orchid To Grow In The Home

Orchids have surpassed the poinsettia in many parts of the country as the biggest selling flowering potted plant.  There are many types though, some quite expensive, with varying growth requirements.  Knowing these, together with which are easiest to grow indoors, can save you money and disappointment from false expectations.

cymbidium orchid

First, decide what you want from an orchid plant.  If you just want the blooms, then your desires and budget are the main limitations.  Since many orchids bloom for a long period under the right conditions, weeks or even months, this may be all you want.  If you want to keep the plants growing indoors as houseplants, blooming in future years, then your choices begin to narrow.

Orchids can be grouped in several ways– keys to their requirements, and so to your success.  Some are terrestrial, or growing in soil, such as the Jewel Orchid (Ludisia) and some Lady Slippers (Paphiopedilum).

Most though are epiphytic, or growing on bark or similar material. These get their water and nutrients from whatever falls on them or their aerial roots.  They are often adapted to high humidity, so fair poorly in dry homes.

The main grouping to be aware of indoors is by temperature requirement.  This comes from the altitude they grow naturally in the tropics.  Those nearest sea level have the warmest and most consistent temperatures, and so are the ones best adapted to similar conditions usually found in homes. These include some of the larger Dendrobium species, Phalaenopsis or Moth Orchids, and Vanda Orchids.

Intermediate-growing orchids are from higher altitudes, where night temperatures fall to 60 degrees during the winter.  Many of these can also be grown indoors, as long as high levels of indirect light are provided, high humidity, and cooler temperatures during winter months.  If you keep you home cooler during winter, perhaps you may wish to try some of these such as the many Cattleya or Corsage orchids and the many hybrids, Laelia, many hybrids of Laelia and Cattleya, Epidendrum, and Lady Slipper or Paphiopedilum.

Cool-growing orchids are from even higher altitudes, where night temperatures reach 50 degrees during the winter. Cymbidium and Oncidium are an example of these, and require quite cool winters with high humidity and high light.

Orchids may differ in their temperature needs, but all grow best indoors with sufficient light and humidity.  Full sun in winter, such as from a south window, is best.  Orchids may also be grown under artificial lights, about a foot above plants and on for about 16 hours a day.

During summer, put plants in indirect light.  Too much light and leaves become light green or yellow, perhaps even brown.  Too little light and leaves may be darker green, slender and twisted; new growth may be horizontal not upright; and plants may not rebloom.

Humidity should be increased from the often 10-15% often found in homes in winter, to around 50-75% around the plants.  This may be done by placing plants on a tray of pebbles kept wet, by misting leaves daily or more often (just make sure and don’t mist furniture and walls!), or by placing plants near a humidifier.  If temperature and light are right, but humidity is too low, plants may not bloom and may grow poorly.

Keep in mind that many orchids only bloom once a year, even under the right conditions.  Some such as Odontoglossum may bloom every 10 months, others such as Phalaenopsis twice a year.

Orchids are quite a large group, and in fact the Orchid family is the largest of flowering plants.  There are over 1000 genera, 25,000 species, and 100,000 hybrids.  So the above recommendations for main genera (such as Vanda and Cattleya) are general, and there are often wide variations in cultural needs depending on species.  Follow these basic rules, though, and you have a good chance of success with the basic orchids you commonly may find for sale.

Dr. Leonard Perry, Extension Professor
University of Vermont

Posted by: marinvit | October, 2009

Grow Hardy Orchids

The main principle for success with hardy orchids is good soil drainage. This may involve building up a raised bed with a good soil, or excavating and replacing some garden soil with a better mix.

This doesn’t imply extensive digging, it could be as simple as making a large hole with good soil. Sand and perlite are two ingredients often used both to increase soil drainage, and to hold the soil moisture that most species need. The soil moisture relates to the three main habitats that include many of the hardy species.

hardy orchid

The upland species are those that do not tolerate constantly moist soil. If your soil doesn’t drain well normally, these may not be the best choice. A hole filled with water should drain in under four hours. Upland orchids usually grow best in full to part shade, but this will vary with hardiness zone and species.

Some hardier species include the Lady Slippers and hardy Chinese orchids. Transition species are those that can tolerate more constant moisture, but thrive under drier conditions similar to the upland species. When flowering, if in a drought, they may need some watering. Otherwise these species thrive in often harsh conditions, and are good choices for many gardens.

A good moisture-retentive soil mix, even if added to the planting hole, is often needed. Hardy transition orchids include the Egret flower, Fragrant Ladies Tresses, Marsh orchid, and Purple Fringed orchid. Wetland species, as their name implies, require constantly moist or even wet soil. They prefer full sun. Unless you have a normally wet soil, you should line the raised bed or planting hole with plastic to retain moisture.

Poke a few holes in the bottom to allow slow water drainage, as these do not like to sit in stagnant water. In nature their roots are in edges of streams or ponds where water is moving, even if slowly. One of the hardiest wetland species is the Rose Pogonia. Three additional tips will help you have success with hardy orchids.

After blooming, remove old flowers. This keeps plant energy going into the roots and not into seed production. When weeding, grasp and hold the orchid plant while pulling weeds. This helps you from pulling up the orchid with the weed. The orchid roots are generally shallow, with the weed roots growing under them.

Then for extra winter protection you may wish to add a couple inches of weed-free straw or pine needles on top. If using leaves, make sure they are ones that don’t pack down tightly.

Dr. Leonard Perry, Extension Professor
University of Vermont

Posted by: marinvit | September, 2009

Hardy Orchids

Yes, there are orchids you can grow outside in the garden.  These are called hardy or terrestrial (meaning in the ground) orchids.  Growing this group of plants can be easier than you think, provided you choose the right species and pay attention to a few cultural needs.

Hardy Orhid

When people think of orchids, they invariably think of the ones among the 20,000 tropical species and even more hybrids that must be grown indoors in northern climates.  Most don’t realize there are over 200 species of terrestrial native orchids that grow in North America.

Since some of these may be endangered in certain states, it is essential to purchase plants from ethical sources– nurseries that have either saved species from habitat destruction, or more often propagated and grown them in their nurseries. One authority for such sources is the New England Wildflower Society.

To dispel two common misconceptions, hardy orchids can be grown in gardens outside their natural habitats, and they can be transplanted.  Tips for which species to choose for what kind of conditions, and their culture, can be found in the book by William Mathis, The Gardener’s Guide to Growing Hardy Perennial Orchids .

One principle for growing hardy orchids is that many not only thrive in temperate, even frigid climates, but some may need below-freezing temperatures to meet cold requirements for bloom (much like tulips and many other perennials).

Another key point in success with hardy orchids is that they don’t need much fertilizer.  In fact, they don’t tolerate heavy fertility.  Usually some compost incorporated at planting, and applied around them in future years, is all that is needed.  If you have nutrient-poor soil, you may fertilize plants lightly with one-quarter strength or rate that you would use normally for flowers.

Dr. Leonard Perry, Extension Professor
University of Vermont

Posted by: marinvit | September, 2009

Orchid Stem and roots

All orchids are perennial herbs and lack any permanent woody structure. Orchids can grow according to two patterns:

Orchid Stem and roots

  • Monopodial: The stems grows from a single bud, leaves are added from the apex each year and the stem grows longer accordingly. The stem of orchids with a monopodial growth can reach several metres in length, as in Vanda and Vanilla.
  • Sympodial: The plant produces a series of adjacent shoots which grow to a certain size, bloom and then stop growing, to be then replaced. Sympodial orchids grow laterally rather than vertically, following the surface of their support. The growth continues by development of new leads, with their own leaves and roots, sprouting from or next to those of the previous year, as in Cattleya. While a new lead is developing, the rhizome may start its growth again from a so-called ‘eye’, an undeveloped bud, thereby branching.

Terrestrial orchids may be rhizomatous or form corms or tubers. The root caps of terrestrials are smooth and white.

Some sympodial terrestrials, such as Orchis and Ophrys, have two subterranean tuberous roots. One is used as a food reserve for wintry periods, and provides for the development of the other one, from which visible growth develops.

In warm and humid climates, many terrestrial orchids do not need pseudobulbs.

Epiphytic orchids have modified aerial roots that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis called velamen has the function to absorb humidity. It is made of dead cells and can have a silvery-grey, white or brown appearance. In some orchids the velamen includes spongy and fibrous bodies near the passage cells. These structures are named tilosomes.

The cells of the root epidermis grow at a right angle to the axis of the root to allow them to get a firm grasp on their support. Nutrients mainly come from animal droppings and other organic detritus on their supporting surface.

The base of the stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form what is called a pseudobulb that contains nutrients and water for drier periods.

The pseudobulb has a smooth surface with lengthwise grooves and can have different shapes, often conical or oblong. Its size is very variable; in some small species of Bulbophyllum it is no longer than two millimeters, while in the largest orchid in the world, Grammatophyllum speciosum (giant orchid), it can reach three meters.

Some Dendrobium have long, canelike pseudobulbs with short, rounded leaves over the whole length, some other orchids have hidden or extremely small pseudobulbs, completely included inside the leaves.

With ageing the pseudobulb sheds its leaves and becomes dormant. At this stage it is often called a backbulb. A pseudobulb then takes over, exploiting the last reserves accumulated in the backbulb, which eventually dies off too. A pseudobulb typically lives for about five years.

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