Angraecums

Angraecums
Angraecum Longidale

Thursday, May 16, 2013

Angraecum germinyanum

     Most of the posts on this page up until now have concentrated on established plants that have bloomed numerous times.  This post will concentrate on the development of a seedling and a plant blooming for the first time.  Both were gifts and required the utmost care in their early stages of growth.  I believe that there is nothing more exciting in an orchid collection than seeing a plant bloom for the first time.
 
Angraecum germinyanum
 
     Angraecum germinyanum original habitat is on the central plateau of Madagascar with elevations between 2950 - 4900 feet (900-1500m).  The plant is considered to be an intermediate to warm grower due to the drastic temperatures of its natural habitat with a high of 93F and a low of 33F (34C - 0C).  The average maximum temps usually range from the low 70s into the mid 80s (22C-28C).  The low temps are reported to have an average of 49F to 62F (9C-16.5C).
     When I received the plant that would initially bloom for the first time, it was in a 2 inch (5cm) plastic pot with bark as the medium.  The stem was just over 4 inches (10cm) tall and covered with very green leaf sheaths.  The leaves are about 2 inches (5cm) long and have a very bright green shine to them.  The root system within the growing medium is just about 2mm wide.  The aerial roots are thinner.  Very mature plants have been reported to be near 40 inches (100cm) tall with 3 - 5 branches extending out nearly 20 inches (50cm) out from the main stem.  This however is rare to find in the wild as well as culture.
 
Singly borne flowers opposite the leaf axil
 
     Flowers are borne singly from opposite the leaf axil with a pedicel of 1 1/4 inch (3cm) long.  The pedicel is connected to a peduncle which usually is less than a 1/2 inch (1cm) coming from the stem.  Angcm. germinyanum flowers can reach a length of 5 - 6 1/2 inches (15-16cm) long.  The lip is turned up (superior type lip) and is 3/4 - 1 inch (1.7-2.3cm) high and wide with a pointed tip at the top of the lip which is about 7/8 inch (2cm) higher.  The sepals and petals are 2 3/4 - 4 inches (7-10cm) long with the petals crossing under the lip.  Both the sepals and the petals are twisted.  The spur is 4 1/2 - 5 1/8 inches (12-13cm) long.  Angcm. germinyanum is not a fragrant flower; but its unusual twisting and unique shape make up for that.
     Once the plant was finished blooming, it was placed in a 4 inch (10cm) terracotta pot.  A medium sized non-organic mix (charcoal, sponge rock and perlite) with a small amount (10%) of coconut pieces was used.  The root system within the medium was minimal showing that it had received to much water.  The regiment for watering the plant was every four to five days giving the root system the opportunity to re-establish itself.  Several new aerial roots started to grow within just a week or two giving the plant a sense of new life.
     After the plant had been in the pot for six months, it proved to be establishing a strong root system.  With late spring temps now in the mid 80sF (29C-30C), the plant is watered every three days and fertilized once a week.  Keep in mind that most Angraecum seedlings and immature plant's root systems can start to rot rather quickly due to the fact the roots are very thin.
     Angcm. germinyanum does have a rest period.  Watering should be reduced and fertilizing stopped for about a three month period.  The plant can be misted between the watering every 5 - 6 days as long as the temps do not drop below 65 F (18C).  Resume a normal watering schedule when you see the growth season begin.  The plant can be re-potted as long as new roots have appeared; paying close attention to not disrupt the root system to harshly.
     With the amount of water that the plant is receiving and the fact that it is in a medium shade type of light, it is best that you be sure to treat the plant on a regular schedule of a systemic fungicide.  I use Thyomil and Dithane 45 on an alternating schedule.  Also make sure that the plant is in an area that will get a good air movement over it.       
     The amount of light that Angcm. germinyanum requires is considered a medium shade, about 1000 - 2000fc (footcandles).  This individual plant is presently receiving an average of 1300fc.  However, it does get direct sunlight for about an hour and a half when the sun first rises.  And absolutely no direct light after that time period.  It has grown about 1 1/2 inches (3.7cm) in the last six months.
 
Angcm. germinyanum seedling
 
     The Angraecum germinyanum seedling above is in its second year of being on the mount.  In the nearly two years, it has barely grown a 1/2 inch (1.3cm).  During the spring and summer growing season, it is watered (saturated) every morning and misted mid-afternoon.  It is my opinion that this seedling should have been kept in the flask longer than it was.  It is however growing a decent root system and as long as it is cared for and watched for any problems, whether those issues be insects (which was a problem the summer prior) or disease, it could eventually bloom; in about three to four years.
     As with any orchid or tropical plant, once a plant is established in a given area, it is best to leave it be in that area.  With the proper amount of water, fertilizer and light, it will bloom and become a mature specimen.

    

Sunday, May 12, 2013

Whats Light Got To Do With It? Part Two

     The presentation titled "Whats Light Got To Do With It" was given to the Boca Raton Orchid Society just a few days ago for the first time.  It was accepted very well by the members that were in attendance.  This post is a review of a post dated back in July 2012 and also a few bits of new information as well.
     I think it is imperative to understand the basic explanations of light when an experienced grower gives a hobbyist (especially a beginner) the light parameters for a plant to grow and eventually bloom.  I have witnessed to often a hobbyist nodding their head and walking away not really understanding what the grower has said.
     At any of the presentations that I give, I thoroughly explain to the audience to take a few moments and research the plant they have purchased.  The are numerous websites, forums and blogs that can supply specific data regarding just about any orchid in our collections. 
     Specializing in the Angraecum Alliance, I have reviewed many of the specific requirements for well over 600 species.  The light requirements will range from deep shade to bright sun light through various parts of the day. 
     It is very common to see a plants light requirements be given in the measurement of footcandles (fc).  Below are several different ways to measure the intensity of light so that you can determine where to place your plants (any type of orchid or plant) so that they can thrive and bloom as they should.

Measuring light levels with a Digital SLR camera:
     Set the ASA or ISO to 100
     Place a piece of white paper in the area you want to measure
     Fill the view finder of the camera with the white paper and be sure that your shadow does not
          interfere with the white paper (it is not necessary to focus)
     Take a meter reading, the following shutter speeds and fstops represent the following:
          1000 fc - 1/2000 @ f2.8
          1000 fc - 1/1000 @ f4
          1000 fc - 1/500 @ f5.6
          1000 fc - 1/250 @ f8
          1000 fc - 1/125 @ f11
          2000 fc - 1/2000 @ f4
          2000 fc - 1/1000 @ f5.6
          2000 fc - 1/500 @ f8
          2000 fc - 1/250 @ f11
          2000 tc - 1/125 @ f16
          4000 fc - 1/2000 @ f5.6
          4000 fc - 1/1000 @ f8
          4000 fc - 1/500 @ f11
          4000 fc - 1/250 @ f16
          4000 fc - 1/125 @ f22
          8000 fc - 1/2000 @ f8
          8000 fc - 1/1000 @ f11
          8000 fc - 1/500 @ f16
          8000 fc - 1/250 @ f22
     If your camera does not set lower than an ISO 200, set it to the 200 and double the footcandles.

Using a photographers hand held light meter:
     Set the light meter to an ASA or ISO to 100
     Make sure the the white cap is covering the meter for ambient light only
     Have the meter pointing up toward the light source and then take the reading
     Once the accurate reading is set, the EV numbers will indicate the footcandles equivilent:
          EV 10 - 168 fc
          EV 10.5 - 336 fc
          EV 11 - 478 fc
          EV 11.5 - 673 fc
          EV 12 - 951 fc
          EV 12.5 - 1345 fc
          EV 13 - 1903 fc
          EV 13.5 - 2601 fc
          EV 14 - 3805 fc
          EV 14.5 - 5382 fc
          EV 15 - 7611 fc
          EV 15.5 - 10763 fc

Your light source, your hand and a sheet of white paper:
     Place a sheet of white paper in the area that you wish to place a plant
     Place your hand twelve inches above the white paper with the light source above
     Looking at what happens to the shadow will determine the type of light you have:
          A very distinctive shadow exists with sharp edges: Vandaceous type light (5500 - 8000 fc)
          The shadow has softened greatly, edges are soft: Cattleya type light (1200 - 5500 fc)
          There is NO shadow at all, appears overall muddy: Phalaenopsis light (150 - 1200 fc)

Be sure to keep an eye on the seasonal position of the sun.  It is highest in the sky with short shadows during the summer (June 21st the longest day) while the sun is lowest in the sky with extremely long shadows during the winter (December 21st the shortest day).