Posted by: marinvit | October, 2010

Orchid Pots

There are many kinds of orchid pots available in the market today. But do not set aside choosing the right pot, because this can greatly affect how your plants will thrive and grow. There is a specific pot that will suit your orchid, so choose wisely.

Orchid pots can be more ornamental, while others possess functional differences. There are many various pots available for orchid growing. It can be confusing to decide, but you can basically pick from plastic or clay pots, also called terracotta pots. Your choice will depend on your orchid type and its watering needs. Each kind has its advantages, and choosing one may depend on the type of orchid you are repotting.

Terra Cotta / Clay Pots
• Clay containers are breathable and heavy.
• Clay pots are porous, which allow roots to breathe.
• Roots do not develop fungus because of the pot’s porous nature.
• The weight of a terra cotta container provides stability for orchids.
• Orchids with less water requirements do well in this kind of pot. An epiphytic orchid does better in a clay pot, as there is less chance of the growing medium becoming waterlogged.
• Orchid potting mixes have larger particles that do not fall through the holes of the clay pots easily.

Plastic Pots
• Clear polythene pots are becoming popular as they allow more light to reach the roots.
• Plastic pots are non-porous which provide less ventilation for the roots of the orchid.
• The growing medium inside plastic pots dries out more slowly, and from the top down.
• When repotting, a horticulturist can have a view on what is going on with the root system and monitor moisture with a plastic pot.

Basket Pots
• Basket containers are another popular container type for orchids.
• Basket pots are common as well for they enable air circulation around the roots which prevent them from rotting.
• A basket container is made of wire, plastic, mesh, wood or pottery.
• As an orchid pot, the basket will need support blocks for your orchid.
• The most suitable materials for support blocks are cork, or the bark of pine or oak.
• Some orchid roots may penetrate the support block and may make it difficult to repot your orchid.

Whatever kind of orchid pots you pick, remember that there is a wide variety y to choose from. If you are an orchid lover, there is a vast amount of happiness to be gained when your orchids bloom.

You must pick the right orchid with the appropriate pot, select the right compost and give adequate light, temperature, water and fertilize your orchid in the proper way. The careful balance of all these will lead you to success in orchid cultivation.

Posted by: marinvit | August, 2010

Orchid Care-Water

Orchid care is more like an art than a science. Of course, you can easily get general directions on how to care for a particular orchid genus. For example, Cattleya needs medium bright light, or Miltonia likes intermediate temperature.

However, there are many “fudge” factors to create the perfect condition for your very own growing environment. All elements need to complement one other for your orchid to thrive. You will also need to observe your plants to gauge their happiness with the current treatments.

Six elements are essential to your orchid care program. These elements are the ones that you provide your orchids on a daily/weekly/monthly basis—water, temperature, light, air movement, humidity and fertilizer. They all work together to ensure the health of your orchids.

Water is essential to the lives of every living thing. That, of course, includes the lives of your orchids. But like all wonderful things, more is not necessarily better. Many orchid plants are killed by their owners because too much “tender loving care” is provided. They suffocate and die. (The orchids, that is, not the owners.) How often should you water? I’m afraid it’s not an easy answer. It will depend on your growing conditions.

“That’s not very helpful,” you say to yourself?

Okay, just to give you some idea, I water my plants about once a week, because I am too lazy to get up earlier in the weekday mornings, and the weekend mornings are pretty much the only time I have. However, I adjust the frequency based on humidity, temperature, light, wind and season. I might do it only once a month in the winter, but twice a week if the humidity is extra low.

You need to have a basic understanding of your orchid’s need. Knowing the type of orchid you have is a good starting point. If your plant is originally from the cloud forest of Costa Rica, where it receives a rain shower everyday, then you know you should keep your plant constantly moist. Here are some general guidelines:

Phalaenopsis (Moth orchids)            Evenly moist all year

Paphiopedilum (Slipper orchids)    Evenly moist but allow to almost dry before watering again

Brassia (Spider orchids)                         Moist during spring and summer (active growth); less so while resting

Cattleya (Corsage orchids)                  Irrigate plenty during active growth, but still let it dry out a bit        between waterings. Less when resting

Cymbidium (Boat orchids)               Evenly moist; less after growth is complete

Dendrobium, Phalaenopsis type        Let dry between waterings

Dendrobium, Nobile type                     Let dry between waterings; withhold in the winter (2, 3 months or so)

Masdevallia Evenly moist all year

Miltoniopsis Evenly moist all year

The appearance of an orchid can also tell you how much H2O it needs. Orchids that have big pseudobulbs (thick base of stem that stores water and nutrients), such as Cattleyas, usually require drying out and do not like to be moist all the time. On the other hand, orchids with no pseudobulbs, such as Paphiopedilum and Phalaenopsis, require a moist condition. So even if you don’t know which type of orchids you have, you can still make an educated guess.

You can also water only when the potting material becomes reasonably dry. How can you tell it’s dry? Even when the surface is dry, the inside might not be. Some people put a bamboo stick or a wooden stick in the potting mix to gauge how wet the inside is. Also, some people just lift the pot up to see how heavy it is. Water only if the pot is light. This will require some experience to tell, but after a couple of weeks, you should be able to tell.

Posted by: marinvit | July, 2010

Temperature & Nutrient Deficiencies

Excess- too high at night , poor flowering

- growth poor as food used faster than made

- leaves fall prematurely

Minimal – water & nutrients absorbed slowly

- yellow foliage & poor development control – can survive short spells if assisted

- reduce or increase temp differential, misting,  shading, humidity, air movement, heating

NUTRIENT DEFICIENCIES

ph - the acidity, i.e. low ph – below 7 or alkalinity , high ph – i.e. above 7 affects the uptake of nutrients

- ideal usually between 5 & 6.5 – there are some exceptions

- organic mediums generally self regulating so ph not so important unless pebble culture, hydroculture used

- problems with nutrient uptake if water excessively acid or alkaline


nitrogen (N)
- for leaf growth and shoot development

- deficient : stunted growth and mature too early old leaves turn yellow and drop


phosphorus (P)
-as a catalyst for flower production and root development

-  deficient – stunted growth dark green leaves/ purple tinge


potassium (K)
– for control of flower and fruit development

- deficient – dwarfing & edges of leaves scorched & dead


calcium (Ca)
– for building cell walls & cell metabolism

- deficient – new growths stunted & distorted


magnesium
(Mg) – part of chlorophyll & food manufacture

- deficient – yellowing between veins, plants don’t thrive


sulphur (S)
– an ingredient of proteins

- deficient – may stunt root growth


manganese
(Mn) – for cell activities

- deficient – poor growth ( trace element)


trace elements
– other chemicals Cu, Mb, B, Zn required only in minute amounts

- generally available in organic media & as impurities in water & fertilizers

Excess – poisonous to plants, loss of new growths,& chemical burn of mature parts

Deficiency – rare but generally poor growth

Posted by: marinvit | June, 2010

Orchid Diseases-Ailments

AILMENTS

Due to deficiencies or excesses of

- nutrients

- horticultural practises

- environmental factors

WATER

Over watering – insufficient oxygen to the roots caused by too high a water holding capacity of media

- impervious (to gaseous exchange) pots

- over potting

- drying prevented by insufficient air movement

Symptoms – older leaves yellow & shrivel

- roots rot and die

Cure – unpot , cleanup, high humidity, lower light

Under watering

- insufficient moisture retention of media

- rarely inadequate frequency or amount

Symptoms – shrivelling of plant

- brittle papery roots

Cure – water lightly, second watering 1 hour later, may need a third, soak individual plants up to 1hour

Water quality – suitability of water

- measured by electronical conductivity i.e. the soluble salt content

HARD WATER - high content of calcium & or magnesium salts

- reduce misting or syringing – deposits on leaves

- at greater than 300 ppm, soap does not lather

Control – acid media e.g. peat moss
– fertilizers with high residual acidity, leaching important

SOFT WATER – high content of sodium salts

- high ec , may be toxic to plants,

- leaf & root tip burn

-can use resinous demineralisers

LIGHT

-measured in foot candles, 1000 ft candles = 10% full sun

-plants may tolerate higher light than that required for optimum growth

- various species & hybrids have different requirements & tolerances

Excess – tolerance dependant on facilities for dissipating heat from leaves direct result from light

- e.g. air temp, humidity, air movement tolerance

- sunburn due to perpendicular suns rays

- pale green & dull leaves , pseudobulbs shrivel

Minimal – due to excessive shading,

- dark green & weak spindly growth

- blind growths reduced flowering

Posted by: marinvit | June, 2010

Orchid Diseases – Fungal rots

  • - can cause death if not controlled
  • - root & rhizome rots – rhizoctonia & fusarium
  • - brown spot leaf rots – pseudomonas
  • - black rots on pseudobulbs- phytophthora & pythium

Causes & Symptoms

Black rotsactually are fungi

- prevalent in cool months & high humidity
– leaf or new growth turn purplish brown surrounded by yellow, quickly spreads to rhizome and further growths, leaf may fall at slight touch

Root rots

- affects plants of any age

- from broken down bark mediums

- poor drainage

- usually confined to roots except small seedlings

- wilting of the plants & shrivelling of pseudoblubs

- yellowing & twisting of leaves

Fusarium wilt

- usually confined to root & rhizomes

- thru cut ends of divided plants

- die within 3-9 weeks , may take a year

- yellow thin shrivelled & twisted leaves

- roots rotten

- rhizome has purple ring & pink tissue in cross section

Bacterial Rots

- usually cause death of plants

-brown spots & rots pseudomonas & erwinia


Symptoms:

bacterial brown spotpseudomonas sp.

- soft water soaked lesion turning brown or black

-advances rapidly

-exudate on leaf containing bacterial

brown roterwinia cypripedii – mostly in paphs

- water soaked spots near middle of leaf

- spot darkens to chestnut brown

- spots enlarging fairly rapidly

- plants become shrivelled mass

soft roterwinia carotovora – infrequent outbreaks

-  enter through wounds

-  wet rot with offensive odour

- rapid spread in roots & leaves & new shoots

- slower in pseudobulbs & rhizomes

Posted by: marinvit | May, 2010

Orchid Diseases- Fingus

Fungus


- two types cercospora sp and anthracnose species

- causes spotting of the leaves and pseudobulbs, occasionally flowers

- rarely causes death, scars remain for life of leaf

- more prevalent in cold, moist, & still conditions

- especially active on devitalised and dead plants

Cercospora symptoms

Chlorosis – fine yellow spots starts on undersurface, first enlarging irregularly-followed by necrosis, death and blackening of tissue followed by irregular enlargement, dead tissue falls out, leaves die

Anthracnose symptoms

Brown irregular discoloration usually sunken, sharply defined between infected & healthy tissue, spore pustules – little brown or black spheres develop (don’t confuse with thrips droppings)

Botrytis symptoms

- flowers only infected, small brown spots, enlarge very little, pink margin

Control:

Prevention

- cleanliness and strict hygiene

- adequate air movement

- control of humidity levels and temperature

- removal of leaves & especially flowers (botrytis is saprophytic)

Cure

- spray at regular intervals usually weekly

- use a wetting agent

- follow safety procedures as for pests

Chemicals

- usually wettable powders

- benlate can cause viral like symptoms in excess

- caftan, zineb, ferbam, daconjl, tersan, thiram, mancozeb

Posted by: marinvit | May, 2010

Orchid Diseases ( part2)

Identification of pest and damage:

Cockroaches, crickets, millipedes, crustaceans

Identification of pest and damage

Damage – eating root tips and flowers

Fungus gnats – larvae of flies, adults minute black, larvae whitish

Damage – seedlings, root tips, in decaying organic matter

Beetles, weevils, grasshoppers etc.

Damage – eating of flowers & leaves or sucking/boring

Ants- not destructors but transporters of scale & mealy bug & aphids . Feed on sugary exudations of insects. Secondary infestation of black sooty mould

Slugs – small charcoal, tigers, large yellows

Damage – slime trails , nocturnal, moist, eating of roots, flowers, new growths

Snails – bush, conical, brown – charcoal, yellowish, small shell for hibernation or prevent desiccation

Damage – bush eat roots & stems, others mainly buds & flowers

Control

Prevention – cleanliness remove dead leaves & old flowers,repot timeously, inspect regularly, act immediately

Cure - insecticides, wettable powders, emulsions, liquid concentrations

- follow instructions implicitly

- always wear safety clothing

-spray in the late afternoon when cooler – dry by nightfall

-avoid watering for a day or two after spraying

-repeat sprays at least twice, at 3-4 summer or 7-10 day winter intervals to kill new born

- full cover spray to point of drip

- sticker or wetter ( sunlight liquid soap)

-work backwards to exit

-do not mix different chemicals

-rotate chemicals to avoid resistance

Chemicals

Systemic – taken up by plant thru leaves & roots

Contact – taken up by insect thru spiracles or ingested through eating

miticides – mites

kelthane, temik, pentac, tedion,

emulsions – waxy scales, thrips

oleum, sevin, malathion, rogor, metasystox

insecticides –    aphids: pirimor

- cockroaches, beetles etc baygon not on plants

-  ants :  diazinon, chlordane

molluscicides – slugs & snails : metaldehyde, mesurol

Generally fungal, bacterial or viral

Posted by: marinvit | April, 2010

Orchid Diseases

Orchids are subject to a number of pests & diseases.

-introduced with newly acquired or non-orchid companion plant

-poor or erratic growing conditions within the greenhouse

-weak & unhealthy plants as a result of poor horticulture

pests – an infestation i.e. the plant is attacked from without

diseases – an infection where the plant is attacked from within

ailment – a deficiency or excess of nutrients & environmental factors

Pests:

generally insects or molluscs

pests – mites

- spider mites, false spider mites

- thrips

- aphids

- mealy bugs

- scale insects

- other insects – cockroaches, weevils, flies, millipedes etc.

- ants

- slugs

- snails

- others

Identification of pest and damage
Two spotted mite  – pale yellow/green, 2 dark spots on sides, 4 pairs legs, rounded

Damage – feed on undersides of leaves, speckled appearance, eventually turning black covered with silvery /bronze webbing, curling under of leaves

False / red spider mite – white/yellow becoming red with age, 3 pairs of legs, rounded

Damage – feed on undersides of leaves, fine pitting turning to a white/yellow flecking (dead cells) general discoloration & leaf drop

Thrips – yellow brown, elongate slender, moves rapidly

Damage – deposit eggs in cells- watery bruise (magnified) of stems & leaves, feed damage – glaucous or rusty spots on leaves, turning black finely spotted transparent or blackish discoloration flowers, distorted buds

Aphids – greenfly, green or black easily visible

Damage – distorted buds, new growths, stems, spikes

Mealy bugs – soft bodied covered in white powdery wax and filaments

Damage – hidden under dry bracts, sheaths & between roots, leaf & stem axils. Suck plant sap, turns yellow

Soft or armoured scale – flattened, rounded yellowish to black, only nymphs mobile

Damage – found on leaf surface, axils, hidden under bracts & sheaths, on rhizomes. yellowing of tissue, leaf drop, some blackening

Boisduval scale    – males in cottony white masses, females whitish circular shields

Damage – in leaf axils, hidden under sheaths and bracts. Yellowing of tissue, some blackening, leaf drop

Posted by: marinvit | April, 2010

Orchid Classification

Orchid type:

Cattleya
Brassavola
Epidendrum
Laelia


light intensity : medium – high

1. ideal – outside in summer time with 50% shading, in winter it requires warming
2. suitable – sunlit window
3. enough – fluorescent light

Cymbidium:

light intensity : medium – high

1.ideal – outside , at mountains area with 50% shading
2. suitable – sunlit window

Dendrobium

light intensity : medium – high
1. ideal – outside – in plain area with 70% shading
2. suitable – sunlit window

light intensity : low – medium

cultivation area:
1. ideal – fluorescent light
2. suitable – shaded window
3. enough – outside with 70% of shading – in mountains area – heat is required.

Miltonia
light intensity : medium
1.cultivation area:
2.ideal: partial lighted window
3.suitable: fluorescent light

Odontoglossum:
light intensity : medium
1.cultivation area:
2.ideal: partial lighted window
3.suitable: fluorescent light

oncidum:
1.light intensity : medium up to high
2.ideal: well lighted window
3.suitable: fluorescent light

Paphiopedilum:
light intensity : low up to medium
cultivation area:
1. ideal – fluorescent light
2. suitable – shaded window

Phalaenopsis
light intensity : medium
cultivation area:
1. ideal – shaded window
2. suitable – fluorescent light

Vanda, Ascocentrum:
up to high light intensity : medium
cultivation area:
1.ideal: sunlit window
2.suitable-

Humidity:
Tropical orchids enjoy relatively high Humidity. The requirement for Humidity is higher with the increase of temperatures. in temperatures of 20 degrees relative Humidity of 40%-50% will suffice, while in temperatures of 30 degrees the requirement for relative Humidity is 60%-70%. you can increase the relative Humidity around the plant by putting the pots above big plates that contain tuff stones with thickness of 4-5 cm. on the bottom of the plate you should prepare a water level of 1 cm. you have to verify that the plants would not be able to absorb water from the plate.

Where can you find orchids for home cultivation?
Many orchids you can find in home garden nurseries or florist shops. But uncommon and unique orchids may only purchased in specialist orchid nurseries.

Posted by: marinvit | March, 2010

Orchid Tips

Tips for Correct Irrigation:

When to Irrigate more frequently:

* High Light Intensity
* High Temperatures
* Relativley Low Humidity
* Constant Air Motion around the Plant
* When the Plant has thin Leaves that are not Fleshy

* When the Plant is attached to a Trunk
* if the Plant is cultivated in Basket
* if the Flower Pot is made of Clay
* Little Flower Pots

when to irrigate less frequently:

* in low light intensity
* low relatively temperatures
* high relatively humidity
* no air motion around the plant
* plant with fleshy leaves
* organic ground
* flowerpots made of plastic
* big flowerpots

The water used for irrigation have to be good quality water (low electric conductivity) hence, one should irrigate with rain waters, those you can accumulate in containers at winter time or you can irrigate with purified water(you can accumulate condensed waters of air conditioner). to the water you add fertilizer (20% nitrogen , 20% phosphorus, 20% potassium in amount of no more than 1 gram fertilizer for 1 liter of water) when irrigating the plants with this solution once a week or more according to the orchid type.

General instructions for orchid cultivation:

Light requirement:

Orchids who’s natural habitat is tall mountains, or tree tops, require relatively high light intensity, therefore you should grow them in well lit balcony or in a green house.

Orchids that grow on the ground in forests or inside tree trunks require lower light intensity, direct sunlight can damage their foliage. thus, those species will succeed more inside the house in a well illuminated area with no direct exposure to sunlight.

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