Shade Cloth for Orchids

Shade Cloth  -- Orchid house

Shade nets are useful in outdoor and greenhouses; they provide physical protection (birds, insects & excessive radiation) and help protect the plant from excessive heat radiation, sunburns and stress following the radiation.

There are two crucial parameters for shade net. One is the shading factor in % and another is color of shade net

Shading factor

Shade nets are available in various shading factors and higher the shading factor, shade net would block more radiation and would reduce the temperature of air, soil and plant inside the shade house.

Right shading factor for orchids is dependent on the location and elevation of the place. I am using a 50% shading factor cloth blocks 50% of the sunlight.

Recommend using a light meter (available standalone or built in in a camera or an iOS app) to decide whether the shade cloth is providing the right amount of light for the orchid you are growing. Measure the light at same location at various times of the day to decide the amount of sun light it is receiving and then decide on the amount of shade net

Amount of light depends on type of orchid. For e.g. Vanda’s require very high light, followed by Cattleya and dendrobium.

Genera	Foot Candles
Vanda	4000 to 6000 ft-candles
Oncidiums, Dendrobiums and Cattleyas	2000 to 4000 ft-candles
Some Paphs	1500 ft-candles

Color of Shade Net

Shade net is usually made out of UV resistant material and scatters most of the UV light. Shade net that scatters the most of the light but does not alter the spectrum of the light provides the best condition for growth.

Color of shade cloth is an important parameter that needs to be considered for Orchid house

Color	Light Scattering	Heat Generation	Full Spectrum of Colors	Comments
Silver color /Aluminum based	★★★★★	None	★★★★★	Best but not available in India
White	★★★★	None	★★★★★	2nd Best
Red	★★★	★★	★★★	Red light increases larger leaf surface, long and thicker stems and promotes early blooming 2nd Best
Black	None	★★★★★	★★★★	Produces more heat. Not suitable for normal temperatures but could be used in Winter to increase heating
Green	★★★	★★	★★	Green light is not useful to plants
Blue	★★★	★★	★★★	Blue light darkens the foliage and shortens the plant  & delays blooming

Black shade net can be used for growing only vanda genus and vanda’s thrive in black as they like the extra heat generation provided by black.

Oncidium Twinkle 'Red Fantasy' in Bloom

Oncidium Twinkle is a primary hybrid between Onc. cheirophorum x Onc. ornithorhynchum. emits the sweet scent of vanilla when blooming

Grow in partial shade in a semi hydrophonic medium.

Vanda coerulea

Vanda coerulea Griff. ex Lindl. 1847 SECTION Longicalcarata

Common Name: The Blue Vanda or Autumn Lady's Tresses

Ancient healers used the juice of the flower was by as eye drops against glaucoma, cataract and blindness. Active ingredients of Vanda coerulea are also used by modern pharmaceuticals to fight against the visible signs of ageing skin.

Vanda coerulea is endangered and is in CITES II

Distribution & Occurrence:

Western Himalayas to Thailand@ elevations of 800 to 1700 Meters.

The Plant

A medium to large sized warm to cool growing epiphyte found in deciduous forest with distinct dry season. Leaf span and Leaf arrangement of Vanda coerulea are different compared to other vanda species.

Vanda coerulea has a very short leaf, that is more or less horizontal and the leaf bracts are more visible and higher than other vanda.

Flowers once year during early or late fall and flower lasts a few months

Cultural Requirements and Nutrition

Vanda coerulea can tolerate more cooler conditions than most of the strap-leaf vandas and will be quite comfortable under intermediate temperatures, Requires strong light and heavy feeding during growth phases.

Pest and Diseases

No specific pests or disease.

Hybrids

Heavily used as pollen parent and seed parent

Bloomed in October 2014

Tips to identify Wild Form of Vanda coerulea

·       Vanda coerulea flowers tend to be somewhat taller than wide and never round

·       Wild and pure forms of Vanda coerulea, petals twist upto 180 degrees and never flat

·       Leaf arrangement is more horizontal and the leaf span is shorter

·       Side lobs of the lip has a sharp hook structure pointing towards the flower and this hook structure disappears after one cross

·       When the flower open started out as almost white and gradually increase their color.

·       On removing pollen from mature flower, and the flower should turn to complete white less than 24 hr. Most hybrids tend to retain the blue color a lot longer and wouldn't drastically noticeable until third day or so

Dendrobium chrysanthum

Dendrobium chrysanthum Wallich ex Lindley 1828 SECTION Dendrobium

Common Name: The Golden Yellow Flowered Dendrobium

Stems of the plant are used in traditional Chinese medicine as a antipyretic, anti inflammatory, eyes-benefiting and immune-modulatory effects

Distribution & Occurrence:

Western Himalayas to Vietnam

The Plant

Large sized cool to warm growing epiphyte, lithophyte @ elevations 350 to 2200 meters. Stems are pendulous carrying bright shiny green leaves. Stems in-situ can grow upto 5-6 feet

Blooms from April-November on leaf axil’s with few to several flowered, racemose inflorescence on the nodes of the upper portion of immature leafed pseudobulbs (does not bloom on leafless canes). Canes starts loosing the leaves after they bloom.

Cultural Requirements and Nutrition

Grow in bright light and is best placed in a wire basket or mounted to accommodate their pendent growth habit. Requires a winter rest to produce blooms the next year. Sparingly mist/water during winter rest and refrain from fertilizing during the winter rest (Nov to Feb)

Pest and Diseases

No specific pests or disease. Dendrobium specific pests & diseases applicable

Hybrids

Extensively used as pollen as well as seed parent.

Bloomed in Sep 2014

Dendrobium longicornu

Dendrobium longicornu Lindl. 1828 SECTION Formosae

Introduction

Common Name: The Long-Horned Dendrobium

Dried flowers of Dendrobium longicornu are used as pickle in parts of Arunachal Pradesh. Juice of stems is consumed for fever and boiled roots fed to livestock suffering from caughs.

Distribution & Occurrence:

Western Himalayas to Vietnam@ elevations of 1200 to 3000 Meters.

The Plant

Small sized warm to cold growing epiphyte with thin slender stems with 5-10 deciduous leaves. Stems are covered with minute black hairs

Blooms in the fall on very short. Racemes arise from the top of the stems with many fragrant, waxy flowers that don’t fully open.

Flowers once year during early or late fall and flower lasts a few months

Cultural Requirements and Nutrition

Grow in bright light with atleast few hours of direct sunlight and medium should dry out soon. Water and fertilize during active growth period in summer and reduce watering in winter with occasional misting and complete withholding of fertilizers during winter

Pest and Diseases

No specific pests or disease.

Hybrids

No registered hybrids

Bloomed in August 2014

Flowers are still intact in Sep 2014