November  22,  1900. 
JOURNAL  OF  HORTICULTURE  ANL  COTTAGE  GARLLNER. 
459 
Notes  on  Vandas. 
Few  of  the  species  in  this  beautiful  Old  World  genus  seem  to  have 
much  attraction  for  orchidists  generally,  and  smill  cultivators 
especially.  A  few  of  the  newer  kinds,  such  as  V.  Kimballiana  or 
V.  Amesiana  (6g.  121),  are  iairly  popular,  and  even  V.  coerulei  finds  a 
great  many  admirers,  but  many  of  the  noblest  in  the  genus,  such  as 
V.  suavis  or  V.  tricolor,  and  V.  Batemanni  are  in  most  cases  con¬ 
spicuous  by  their  absence.  In  too  many  private  gardens  it  is  the 
custom  to  give  these  Vandas  too 
much  heat  and  insufficient  air, 
especially  at  this  season.  Because 
they  come  from  a  tropical  country 
cultivators  apparently  think  that 
they  cannot  be  overdone  with  heat, 
consequently  they  have  to  make 
the  best  of  their  existence  among 
the  very  warmest  section  of  the 
family,  with  the  result  that  after 
the  first  season  or  two  the  foliage 
is  weakened  and  falls,  and  few 
flowers  appear. 
Insects  also  find  in  debilitated 
plants  just  what  they  like,  and, 
owing  to  their  attacking  the  few 
sound  leaves  that  are  left,  the  poor 
Vandas  pn  sent  a  sorry  appearance 
indeed.  Contrast  such  with  plants 
grown  in  a  suitable  temperature. 
Here  we  see  vigorous  growth,  a  plant 
that  is  ornamental  before  it  produces 
a  flower,  and  when  in  blossom  a 
magnificent  sight  that  well  repays 
the  trouble  taken  by  the  cult  vator, 
and  elicits  no  end  of  encomiums 
from  interested  visitors.  • 
A  ft  w  degrees  of  heat  one  way 
or  another  make  little  difference  to 
Vandas.  What  they  want  is  a 
constant  and  regular  supply  of  air, 
a  nictly  balanced  temperature  as 
regards  moisture  and  heat,  and  most 
important  of  all,  abundance  of  light 
without  being  scorched  by  bright 
sunshine.  Many  of  the  fine  con¬ 
servatories  in  various  parts  of  the 
country,  with  their  wealth  of 
climbers  on  the  roof  breaking  up 
the  rays  of  the  sun,  would  make 
ideal  houses  for  Vandas.  In  these 
spacious  structures  the  temperature 
keeps  steady,  the  plants  may  have 
.  a  good  light  without  being  too  close 
to  the  glass,  and  the  ventilation  does 
not  mean  the  licking  up  of  every 
drop  of  moisture.  No  fear  of  such  plants  losing  their  leaves  in  winter, 
even  supposing  the  temperature  drops  a  little  lower  than  usual ;  and 
this  leads  up  to  a  fact  that  is  often  lost  sight  of  by  orchioists — viz., 
that  most  Vandas  are  quite  safe,  and  indeed  happy,  in  a  winter 
minimum  temperatuie  of  from  45°  to  50°.  It  induces  complete  rest 
and  minimises  the  risks  of  attacks  from  insects,  the  plants,  moreover, 
being  much  more  floriferous  than  others  kept  warmer. 
Vandas  of  many  kinds  may  also  be  well  grown  in  vineries ;  indeed, 
the  suitabdiiy  of  these  houses  for  Orchids  of  various  kinds  during 
the  summer  is  not  nearly  as  well  known  as  it  ou’ht  to  be,  the 
plants  grown  there  being  decidedly  the  better  for  the  change,  while 
the  increased  room  in  the  Orchil  houses  projjer  must  conduce  to  the 
well-being  of  those  left  behind.  There  are  some  Vandas,  it  is  true, 
that  must  have  more  heat  than  others — in  fact,  that  can  hardly 
be  kept  too  warm  while  growing,  the  peculiar  V.  teres  being  a  well- 
known  instance  of  this.  V.  Smderiana,  too,  the  King  of  Vandas  as 
it  has  been  termed,  likes  tr  pic.il  treatment  while  growing  ;  but  these 
are  only  exceptions  that  p.-ove  the  rule,  and  the  fact  remains  that  the 
great  majoiity  in  the  genus  are  too  liberally  provided  with  heat.  In 
most  of  the  species  it  is  easy  to  see  that  the  growing  season  is  com- 
.mmcing,  anl  also  when  it  is  finished,  by  the  appearance  of  the  roots. 
These,  it  will  be  noticed,  when  the  plants  are  in  full  growth, 
have  soft  green  points,  round  which  the  tender  spongioles  may  be 
easily  seen  by  the  naked  eye.  This  shows  that  they  are  seeking  for 
moisture,  and  consequently  as  long  as  the  green  points  are  visible 
this  must  not  be  withheld.  In  autumn,  however,  a  white  film 
comes  over  these,  and  although  clinging  as  firmly  as  ever  to  the 
compost  or  the  side  of  the  pot  or  basket,  they  are  not  so  active  in 
their  search  for  moisture. 
By  degrees,  then,  the  cultivator  must  lessen  the  supply  of  water  ; 
not  alt  at  once,  or  the  foliage  would  suffer,  until  in  winter  very  little 
will  suffice,  the  plants  in  fact  being  kept  going  for  weeks  by  the 
atmospheric  moisture  without  a  drop  being  poured  on  the  roots. 
A  little  different  treatment  of  course  is  required  by  different 
species,  and  as  a  rule  the  smaller  growers  require  watering  oftener 
than  larger  ones,  owing  to  the  greater  capacity  of  retaining 
moisture  in  the  receptacles  wherein  the  latter  are  grown.  For 
compost  sphagnum  moss  will  suffice,  the  only  needful  addition  being 
plenty  of  some  hard  substances,  as 
charcoal  or  crocks,  in  various  sizes 
according  to  that  of  the  pot  or  basket. 
The  latter  are  best  for  the 
smaller-growing  kinds,  and  also  for 
small  plants  of  the  more  robust 
species.  There  are  various  other 
details  requiring  attention,  and  these 
vary  with  the  differing  species. — 
Obciiidist. 
Oncidium  varicosum  Rogersl. 
Flowers  of  this  grand  form  are 
already  to  hand  from  one  of  my 
correspondents.  Cheap,  and  easily 
obtained,  it  is  no  wonder  it  is  so 
popular,  the  only  pity  is  that  it  does 
not  continue  longer  in  a  healthy 
state  in  our  Orchid  houses.  Of 
course  in  many  cases  cultivators 
themselves  are  to  blame.  They  will 
persist  in  allowing  the  spikes  of 
flower  to  remain  on  weak  and  poorly 
established  plants,  with  the  result 
that  they  never  recover  from  the 
strain.  I  have  found  it  do  best  in 
a  clear  light  in  an  intermediate 
house,  the  roots  being  confined  to 
rather  small  baskets  or  pans. 
Trichosnaa  suavis. 
Complaints  are  frequent  anent 
this  pretty  species  not  throwing  its 
blossoms  sufficiently  high  to  show 
properly,  and  although  possibly  in 
some  cases  it  is  the  fault  of  the 
grower,  there  is  no  doubt  it  is 
peculiarly  liable  to  this  defect.  In 
some  cases  the  plants  are  allowed 
to  flower  before  they  are  properly 
established,  and  being  naturally 
weak  at  such  a  time  their  energies 
are  much  overtaxed  in  producing 
the  flowers,  the  consequence  being 
that  these  open  too  soon,  are  never 
good,  and  piematurely  decay. 
The  best  preventive  of  the  mischief  is,  it  goes  without  s^y’ng,  to 
arow  the  plLts  strongly  and  well.  The  roots  are  very  lable  to 
injury  from  defective  drainage  or  soured  compost,  consequently  great 
care  is  necessary  in  preparing  the  latter  and  in  maintaining  it  m 
proper  condition.  This  done  one  of  the  chief  causes  of  failure  s 
removed,  and  I  have  found  it  a  very  great  advantage  in  this  connect  on 
to  allow  considerably  more  sphagnum  moss  than  P' 
up  the  compost.  Besides  the  compost  it  is  important  that  abundance 
uf  moisture  and  an  almost  unlimited  supply  of  fresh  air  be  maintained. 
These,  with  shade  when  required,  the  leaves  kept  cool  in  suminer, 
and  a  good  clear  light  from  now  until  the  spring,  form  ideal  conditions 
for  its  continued  health.  Thrips-the  bane  of  its  existence  m  badly 
managed  collections-will  be  practically  unknown  when  these  few 
details  are  carried  out,  and  provided  the  p  ants  have  a  firm  hold  o 
the  home  of  their  adoption  and  are  sufficient^  strong  there  w  [ 
no  cause  for  the  complaint  noted  above.  The  best  of  all  positions 
for  it  is  a  h,'  use  slightly  warmer  in  winter  than  the  very  coolest 
section  delights  in— such  a  one  as  suits  Odontoglossuiu  grande  and 
its  allies.  Its  native  home  is  on  the  Khasia  Hill-s  where  the  late 
Mr.  Gibson,  at  that  time  collector  for  the  famous  Chat8^^orth  collectio 
.TT  U  R 
