What's Light Got To Do With It?

     EVERYTHING!

     NOTE: This post is to give anyone an idea how I determine the quality and quantity of light for my plants.  The conditions that you reside in will vary in different amounts.  Use this as a stepping stone to determine the light for your plants!
     At every lecture/presentation that I've done over the last four years, one of the most common questions has dealt with light.  As I have said numerous times, "Give an Angraecum what it requires and it will reward you with years of some of the most unique flowers you can encounter in the orchid world".  So keep in mind that there are Angraecums that require bright light (direct sunlight to some extent), there are some that thrive in medium to dark shade and then there are some that don't really seem to care and will do well in just about any type of light.  Use a specific culture sheet to help guide you!
     The easiest way to read the light reaching a plant would be to use a light meter of some sort.  There are several that will give you an accurate and/or usable reading in foot candles (the measurement that seems to be used by many professional growers when needing a unit measurement).  I have one called the "Rapitest" that has been dependable and did not break the bank as far as cost was concerned.  I purchased it at an orchid grower's nursery.

"Rapitest" Sun Analyzer

     It is easy enough to use.  Point the meter towards your light source, multiply the number the needle shows by 1,000 and you have a usable unit of measurement in foot candles.  Keep in mind that the numbers will vary depending on the time of year (seasonal changes in the position of the sun).  The north and south light will change the most.  Summer light from the north will be higher than winter's light and the light in the south will increase with the sun in the southern sky.  East and west light will have a minimal amount of change to the light. [Added May 12, 2013 - one of the problems that has come to my attention with the "Rapitest" Sun Analyzer is that it seems to loose some of its ability to accurately read the light after about 12 - 18 months; both of the "Rapitest" meters have dropped about 10% of the reading it gathered when newly purchased.]

     Another way to measure light is with a traditional photographic light meter that can give you an EV (evaluation) reading.  I use Gossen's "Luna-Pro F".  The meter is used in the ambient light mode (light that will reach your plant).

 Gossen "Luna-Pro F" Photographic Light Meter

     Set the ASA/ISO at 100.  Face the white dome toward the light source.  Press the larger red button on the left side of the meter in once (the smaller red button should be in the "IN" position) and then turn the dial until the needle is at the center mark "0".  The EV number will be at the bottom of the dial under the down pointing diamond mark.  The chart below contains the EV conversions to foot candles.

EV 9 - 119 fc

EV 10 - 240 fc

EV 11 - 476 fc

EV 11.5 - 673 fc

EV 12 - 951 fc

EV 12.5 - 1,345 fc

EV 13 - 1,903 fc

EV 13.5 - 2,691 fc

EV 14 - 3,805 fc

EV 14.5 - 5,382 fc

EV 15 - 7,611 fc

EV 15.5 - 10,763 fc

EV 16 - 15,221 fc

EV 16.5 - 21,526 fc

     Then again, you can always set the technical information aside and just read the light by eye.  The following list is what I use with most of my plants.

Heavy Shade; 150 - 275 fc

Medium Shade; 350 - 500 fc

Bright Shade; 600 - 900 fc

Heavy Spackled Sun; 600 - 1,200 fc

Medium Spackled Sun; 1,200 - 1,600 fc

Light Spackled Sun; 1,600 - 2,000 fc

Full Summer Sun AM; 2,500 - 5,500 fc

Full Summer Sun NOON; 5,500 - 8,000 fc

Full Summer Sun PM; 8,000 - 6,000 fc

*NOTE: These numbers represent summer foot candle measurements and will vary at various altitudes, various seasons and air qualities.  Be sure to keep a close eye on your plant placements and to watch for sun burn.  These numbers were also derived for my plants in South Florida (a sub-tropical climate in the northern hemisphere).  

       

    

Angraecum magdalenae

     Angraecum magdalenae is very often referred to as the Queen of the Angraecums.  It is one of the parents to Angraecum Lemforde White Beauty.  A hybrid that resembles the Queen herself but only larger.  It is in my opinion to be one of the most impressive orchids in existence today.

Angraecum magdalenae (photo by mini-catts)

 

 

     One of the problems with hobbyists growing Angcm. magdalenae is that they misunderstand the label information if the grower they purchased the plant from has prepared a proper label.  You will see info such as blooming time as S (spring), SU (summer), F (fall) and W (winter).  You may see the type of light that is required and sometime watering conditions.  On many angraecum tags you will also see climate conditions such as C (cool), I (intermediate), W (warm) and once in a while H (hot).  Do not make the mistake and think that it is what the plant requires; what it means is what the plant will tolerate.  Their is a huge difference.
     Another thing to keep in mind is that reading culture information on Angcm. magdalenae or any other type of orchid is to know the differences between the northern and southern hemispheres.  Such as blooming, growing and cool/dry periods are opposite times of the year.  In the east mountains of Madagascar where the plant at one time was prolific, Angcm. magdalenae blooms from mid-December into late February.  Here in the northern hemisphere, it blooms late May into early August and will on occasion bloom into mid September in culture due to the care we give to our orchids.  That extra care that mother nature does not always extend.
     Angcm. magdalenae will do best in a 6 - 7 inch shallow pot (15-18cm) in a combination of fine and medium size mixture of sponge rock (aliflore or perlite will substitute well), charcoal, fine pieces of tree fir and sphagnum moss (helps keep the roots damp).  Do not use regular tree bark.  It breaks down to quickly and you would then have to try to re-pot.  Messing with the roots on this plant can and usually will prevent the plants from blooming for 2 - 5 years.
     The stem of a mature plant can reach 14 inches (35cm) in it's natural habitat.  Although in culture it will grow to about 10 inches (25cm).  Leaves will be alternating to each side of the stem being 8 - 12 inches long (19-30cm) and appear fan like.  A mature plant will also have numerous basal keikes which will bloom while the stems are still short; however they usually bloom after the main plant has.
     Given a very bright type of light (it can handle direct sunlight without burning the leaves), Angcm. magdalenae should flower each year.  Too little and the plant will not bloom.  Climate conditions will also come into play here. The climate conditions are C - I (I - C), cool to intermediate.  The plant will grow in warmer temps but may not flower.  It prefers a day - night variance of about 20 - 25 degrees Fahrenheit with max temps not going much higher than 80 degrees F.  With it's growing season being mid-summer here in the northern hemisphere, temps very often reach the mid 90s and even into the 100s in certain areas.  It would serve the plant well to be moved into a smoke free, air conditioned room with a window facing west or even south.
     Air movement is important also.  In the natural environment, the mountains that Angcm. magdalenae grow on have a very regular amount of breezes.  In a home or a green house, the air movement should be a cross type of breeze.  Using a circulating fan above the plant, the fan only spins the same air around rather than constantly bringing in fresh air.
     During the late spring into early fall, water the plant so that the roots are always damp or moist.  Do not let the roots dry out.  If that happens, the plant will not absorb the right amount of water or nutrients to thrive.  From late fall into mid spring, watering can be backed off slightly; but still try to keep the roots from completely drying out.
     Keep a small amount of time release fertilizer in the pot and fertilize every 7 days during the growing season and every 10 - 14 days during the winter here in the northern hemisphere.  A systemic fungicide should be used every 4 - 6 weeks.  Watch for black spots or patches on the bottom of the leaves.

Angcm. magdalenae (photo by Lynne Tyson)

 

 

     A mature blooming plant will produce numerous inflorescence with 2 - 3 flowers on each.  The inflorescence develop underneath the leaves and are short with the blooms beinging tight to the plant.  Flowers will appear on the younger basal plants but usually don't open until the main plant has already bloomed.  Flowers are about 4 inches (10cm) high by 3 - 3 1/2 inches (8-9cm) wide.  The spur or nectary is about four inches (10cm) long and is shaped slightly like an S.  The lip is broad and each of the petals and sepals are widest towards the center of the flower coming to a point at the tips.  Flowers are fragrant throughout the evening and into the first couple of hours of day light.  The fragrance is a deep spicy smell.  Flowers on a well cared for plant can last 4 -6 weeks.

Angraecum distichum

     Angraecum distichum, native to Central Africa, particularly Cameroon, Gabon and Uganda.  As it's name suggests, it is also known as the Two Rowed Angraecum for the bright green, triangular and succulent type leaves.  Angraecum distichum is very often grown for the foliage alone.  Flowers being a secondary thought.

Angraecum distichum

     As with any other angraecum, give the plant what it needs and it will flourish.  It is an easy one to grow but very slow growing.  And as it has been written in the past, DON'T MESS with the roots.

     Because of the way it grows, distichum will grow into clumps.  As the years pass by, the clump will continue to expand.  Mature plants have stems that can reach to 8 inches (20cm) but most will top out at about 6 inches (15cm).  From the end of one leaf across the stem to the end of the leaf on the opposite side averages about 1 inch (2.5cm).  It is common to see keikis develop at the base of the plant as well as branching from various sections of the overall length as seen in the image below.

4 keikis on a mature stem

     Angraecum distichum can be grown either in a small pot or mounted to wood, cork or a tree fir material.  If grown in a pot, be sure to use a medium that will last a while.  As stated earlier, the roots do not like being disturbed.  A fine mix of perlite, charcoal, small pieces of coconut and some moss work well.  If mounted, use moss around the base of the plant engulfing the roots so that they have access to the moisture that the moss holds after watering.

     You shouldn't have to worry about watering the plant to much.  Try to keep the moss or potting material damp year round.  During the winter season, watering can be cut in half due to the plant's ability to hold moisture and nutrients in it's leaves.  If you see wrinkles appear on the leaves, increase your watering.

     Fertilizer should be applied once every 7 - 10 days.  A systemic fungicide can be be used every 2 -3 months (I mean months).  The plant seems to be resilient towards most fungus and other diseases.  There will also be little if any pest problems.

    

 Angraecum distichum

     Flowers will bloom year round on a mature plant.  Their size is about 1/2 inch (12mm) and are borne singularly from between each leaf.  The nectary or spur is about 3/8 inch (9 - 10mm) and usually sticks out straight behind the bloom.  The lip and the dorsal sepal are in opposite positions; where-as the lip becomes hood-like.  The flowers are fragrant (they say), I would suggest not to inhale to deeply trying to smell the fragrance.  You could possibly inhale the bloom itself and get it stuck in your nasal passages.  The blooms have a tendency to come off easy.

     Angcm. distichum gets by very well in low light; even in a medium shade.  It does very well when sitting in a north facing window or on a table in an area that receives north light.  In areas with a much colder climate (an actual winter with snow), these window sills or tables are perfect.

Angraecum Images 2

     This is the second group of Angraecum images in the blog. 

Angraecum calceolous

Aerangis citrata

Aeranthes Grandiose

Angraecum Crestwood

Angraecum distichum *

Angraecum scottianum

Jumellea comorensis

   Jumellea comorensis

     Jumellea comorensis is fairly easy to grow (probably the easiest from the Angraecum Alliance and it does grow rather quickly compared to other angraecoids).  It is native to the Comoro Islands and is a species that can adapt to very bright light and also to very low light.  It is an epiphyte that grows on very rough barked trees.  The average amount of rain fall averages 200 inches a year in the wild and usually found in an area that gets a fair amount of air movement which helps dry the plant leaves and prevent severe fungus problems.
     In culture it will grow well in a 3 - 5 inch pot (8 - 13cm) or basket and will thrive just as well mounted.  If growing in a pot or basket, be sure to use a medium material.  A good balance of coconut, perlite, charcoal and a small amount of moss.  The root system will grow year round but will slow in cooler months.  Roots will grow freely about two thirds of the way up the stem.
    Watering this plant while mounted should be daily during the summer months and every two to three days if in a container (pot or basket).  When temperatures start to drop in mid fall, cut back on watering the plant by a day or two.  Be sure to keep the plant in an area that receives a good cross breeze to help dry the plant of any excess moisture.
     Fertilize the Jumellea comorensis every 7 days and use a systemic fungicide every 3 - 4 weeks to prevent fungus growing on the bottom of the leaves which can be a common problem due to the amount of water the plant needs.

Jumellea comorensis

     Jumellea comorensis will flower year round on an established plant with many flowers.  Each flower being borne singly from the leaf axils.   Flowers are about 1 1/2 inches wide (4cm) and 2 inches high (5cm).  The lip is longer than it is wide and the spur is about 4 1/4 to 4 3/4 inches long (11 - 12cm); the spur will turn a greenish color about half way down.

Jumellea comorensis

     In locations that have a much cooler climate, the plant will grow better in a 5 inch (13cm) pot.  An ideal place would be in a heated green house; but if grown in a home on a window sill or on a table next to a window, the east would be a great place for the plant.  Be sure that the plant will not freeze if on the window sill.  Water the plant about once every 5 - 6 days keeping an eye on the medium, most homes in the winter have little humidity. It can be fertilized twice a month.  When temps are back in the upper sixties or low seventies and night time temps don't drop below 60 degrees, the plant can be moved outdoors.  Treat the plant with a good systemic fungicide.  



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