JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
December  21,  1899. 
538 
POTATOES  BLACKENING  WHEN  BOILED. 
Regarding  the  vexed  question  of  the  discolouration  of  Potatoes 
when  in  the  process  of  cooking  (or  immediately  afterwards,  when  it 
is  the  more  apparent),  the  fact  that  recently  a  dish  of  Up-to-Date 
came  under  my  notice,  and  two  or  three  of  the  finest  tubers 
were  much  blackened,  brought  to  mind  the  paragraph  on  the 
subject  in  the  Journal  of  Horticulture ,  November  17th,  1898, 
page  375,  in  the  proceedings  of  a  meeting  of  the  Royal  Horticultural 
Society’s  meeting,  held  on  November  8th,  to  the  effect  that  “  Mr. 
Richard  Morse  forwarded  raw  and  cooked  Potatoes  to  show  the 
difference  in  those  cooked  as  grown  in  a  field  and  in  the  garden. 
“The  latter  were  much  blackened,  but  not  the  former.  They  were 
the  variety  Windsor  Castle.  The  soil  of  the  field  was  red  with  the 
presence  of  iroD,  consequently  there  was  little  doubt  that  the  tannic 
acid,  being  liberated  by  boiling,  united  with  some  salt  of  iron, 
producing  tannate  of  iroD,  the  usual  ingredients  of  ink.  Mr.  Michael 
observed  that  it  was  of  common  occurrence  in  the  peaty  soils  of  Skye, 
and  even  preferred  by  the  local  inhabitants.”  Evidently  it  must 
be  a  misprint  in  the  statement  that  “  the  latter  were  much  blackened 
but  not  the  former,”  inasmuch  as  the  garden  soil  was  not  described. 
My  chief  object,  however,  in  thus  chawing  attention  to  the  subject 
is  with  regard  to  the  presumed  action  in  the  boiling  process  in 
liberating  the  tannic  acid,  which,  uniting  with  some  salt  of  iron, 
produced  tannate  of  iron,  and  the  question  appears  to  me  that  the 
boiling  process  is  not  alone  responsible  for  the  discolouration,  as  the 
steaming  process  or  roasting  iu  an  oven  produces  the  same  phenomenon, 
hence  intimating  that  the  natural  moisture  contained  in  the  tuber 
during  the  cooking  is  the  acting  agent,  and  not  the  boiling. — W,  G. 
ROOK  GARDENS  AND  ROCK  PLANTS. 
Of  all  the  many  forms  of  growing  and  cultivating  flowers,  we 
think  that  those  coming  under  the  above  heading  contain  some  of 
the  most  fascinating.  You  may  find  here  “pleasures,  which  nowhere 
else  were  to  be  found,  and  all  Elysium  in  a  plot  of  ground.”  The 
novelty,  the  delightful  variety,  and  charm  which  the  rock  garden 
lends  to  the  cultivation  of  flowers  can  scarcely  be  estimated,  for 
within  its  bounds  you  can  grow  a  host  of  dainty  little  gems,  which 
would  be  lost  or  relus-e  to  grow  in  the  ordinary  garden  border. 
Over  the  rocks  are  trailing  the  fragrant  sprays  of  the  Twinflower, 
exhaling  such  a  flavour  of  the  woods  as  to  wiu  the  love  of  the  great 
Linnaeus,  and  therefore  named  in  his  honour  Linnsea  borealis;  while 
there  at  the  foot  of  another  rock  the  soil  is  carpeted  with  a  thick  mat 
of  dark  leaves,  covered  with  cool-look  in?,  lilac-scentcd,  star-like, 
white  tubular  flowers,  Mitchella  repens.  Through  this  carpet  may 
upstart  some  graceful  wild  Wood  Lily  or  lovely  Narcissus,  looking 
self-possessed,  bending,  at.d  nodding  to  every  passing  breath  of  wind. 
In  another  corner  up  peeps  the  small  Soldanella,  or  may  be  that  alpine 
gem  Gentiana  verna,  whose  funnel-shaped  flowers  flash  out  their  deep 
blue  light  beside  the  emerald  green  fronds  of  some  choice  hardy  Fein. 
Yes,  the  rock  garden  is  unquestionably  the  most  characteristic  and 
interesting  home  for  real  alpine  gems,  of  which  we  have  a  constant 
round  of  variety,  developing  and  thriving  among  the  stones  or  rocks, 
where  the  roots  have  found  a  cool  resting  pilace. 
In  speaking  of  a  rock  garden  let  us  draw  attention  to  the  fact  that 
in  no  sense  must  it  be  identified  with  those  base  embellishments  styled 
“  rockeries,”  with  which  we  are  constantly  being  brought  in  contact — 
nightmares  of  boulders,  old  stumps  or  brick-yard  clinkers,  specially 
selected  because  they  may  contain  some  hole  or  cavity  into  which 
even  the  smallest  possible  quantity  of  so  1  can  be  pushed,  and  into 
which  scanty  pasture,  whe  e  even  a  Stinging  Nettle  would  call  out  for 
mercy,  one  of  the  daintiest  of  alpine  plants  is  turned  out  and  ex¬ 
pected  to  thrive,  but  only  pines  away  and  dies.  Some  tough  or 
weedy  kind  like  a  Sedum  or  Sempervivum  may  survhe  the  broiling 
ordeal,  but  even  these  do  not  thrive,  they  simply  exist. 
In  forming  a  rock  gaiden  it  must  be  borne  in  mind  that  most 
alpine  plants  love  to  run  deeply  into  the  soil  in  search  of  moisture  ; 
therefore  must  we  attempt  to  imitate  the  conditions  under  which  they 
exist  in  their  own  wild  homes  by  selecting  a  site  fitted  for  the  object 
in  view.  Two  thii  gs  are  required  to  begin  with,  and  these  aie  soil 
and  stones,  and  of  the  two  the  first  is  the  more  important;  many  fail 
from  thinking  of  stones  first  and  sod  afterwards.  The  soil  should  be 
ordinary  sandy  loam,  with  the  addition  of  a  small  portion  of  leaf 
mould  and  a  large  proportion  of  sand  and  gritty  matter.  Such  a 
compost  meets  the  wants  of  a  large  majority  of  alpines,  but  a  few 
peat-loving  plants  must  be  specially  provided  for.  The  stones  or 
rocks  used  should  be  porous,  for  few  alpine  plants  can  subsist  on  im- 
penetiable  rock  ;  they  like  to  cling  to  it,  and  to  push  their  tiny  roots 
into  the  fissures  to  suck  therefrom  moisture  to  support  themselves. 
In  the  formation  of  the  rock  garden  it  must  alwajs  be  borne  in  mind 
that  alpine  plants  thrive  much  better  on  the  level  ground  in  ordinary 
sandy  loam  thau  exposed  to  every  breath  of  drying  air  and  the  rays  of 
a  scorching  sun.  The  soil  should  be  first  formed  into  whatever  shape- 
the  rock  garden  is  to  take,  and  then  the  stones  must  be  firmly  em¬ 
bedded  therein,  leaving  sufficient  space  between  them  for  the  root 
development  of  the  plants.  Some  of  larger  stones  may  be  placed 
widely  apart,  with  smeller  angular  stones  embedded  in  the  soil  betwixt 
them,  in  order  to  keep  the  soil  moist  and  open  ;  others  may  be  placed 
closely  together,  some  deeply  embedded  only  showing  their  surface ; 
whilst  others  rise  above  the  surface  at  various  heights,  by  which 
means  every  variety  of  position  is  secured  for  the  plants.  Some 
want  partial  shade ;  while  others  prefer  to  hug  the  stones  with  their 
rootp,  and  succeed  best  in  the  narrow  fissures. 
Where  to  place  the  rock  garden  will  depend  much  on  the  surround¬ 
ing  ground.  Nothing  can  be  more  beautiful  than  if  placed  at  the 
bottom  of  an  incline,  perhaps  in  an  old  pit,  imitating  a  natural  grotto 
half  smothered  in  plants  and  Ferns  ;  or  near  trees  that  would  afford 
abundant  shade  ar.d  moisture  for  the  shadow-loving  plants,  and  also 
shelter  from  rude  winds.  If  one  can  introduce  water  into  the  scene 
by  all  means  do  so. 
Let  us  now  endeavour  to  peep  at  some  of  the  garden’s  occupants 
as  they  hurry  before  us  into  life,  commencing  with  the  spring  of  the 
year.  rJ  he  first  few  warm  days  reveal  wonders.  You  have  the 
charming  Scillas  with  their  bell-shaped  flowers,  while  between  the 
chinks  of  the  rocks  rise  the  no  less  beautiful  Hepaticas,  glowing  in  all 
the  shades  of  blue,  purple,  and  rose,  shading  off  to  lavender,  soft  flesh 
tints,  and  pure  white.  We  cannot  pass  that  sweet  harbinger  of  spring, 
our  native  Primrose,  and  its  near  allied  forms  of  Primula,  an  endless 
variety  of  shades  from  the  yellow  Cowslip,  the  crimson  Primroses  and 
Polyanthuses,  the  edged  and  powdered  Dusty  Millers,  the  deep  rose 
umbels  of  P.  cortusoides,  the  fiery  P.  rosea,  the  bright  mauve 
P.  denticulata,  the  pule  yellow  fragrant  P.  sikkimensie,  the  high 
coloured  hybrids,  the  Bird’s-eye  Primrose,  and  others  too  numeious 
to  mention,  not  forgetting  that  gem  of  the  Rocky  Mountains, 
P.  Parryi,  with  its  tall  stalks  of  fine  rose-coloured  blossoms. 
We  must  also  stop  to  admire  Saxifraga  oppositifolia  and  its 
varieths,  which  is  a  native  of  some  of  our  own  mountain  raoges,  and 
is  one  of  the  jewels  of  the  rock  garden.  Space  will  not  allow  us  to 
dilate  on  the  rosy  cordifolia,  the  gigantic  peltata,  the  longifolia,  and  a 
host  of  others.  We  cannot  enumerate  all  the  items  in  the  feast,  but 
in  conclusion  we  wish  to  draw  attention  to  a  few  practical  hints.  Do 
not  utilise  plants  that  sucker  or  throw  out  strong  creeping  rootstalks; 
do  not  plant  in  lines — plants  are  not  regiments  of  soldiers;  do  not 
plant  on  the  dot  and  carry  one  principle — variety  is  the  spice  of  the 
garden,  therefore  mass  boldly,  net  confining  yourself  to  a  few  kinds  of 
plants  where  there  is  so  much  to  choose  from  ;  do  not  imitate  others, 
produce  your  own  ideal  of  a  garden  ;  and  do  not  plant  coarse  weedy 
subjects,  but  think  twice  before  you  decide  to  introduce  another 
variety,  but  plant  for  permanency,  adding  something  every  year. 
Few  realise  the  richness  of  a  reck  garden  ;  few  are  familiar  wilh 
its  infinite  grace  and  beauty ;  and  fewer  still  appreciate  many  of  our 
wild  flowers  thriving  under  proper  cultivation,  and  how  much  they 
add  to  the  charm  of  the  garden. — T.  Gee. 
DOUBLE  TUBEROSES. 
These  half-hardy  bulbous  plants  are  useful  in  the  early  part  of 
the  year,  if  means  for  forcing  growth  are  available;  they  may  be 
grown  in  frames  and  even  outdoors,  but  they  will  be  consequently 
later  in  flowering.  Africa  supplies  the  first  consignment  of  bulbs, 
and  these  are  ready  for  potting  in  September  and  October.  The 
American  varieties  and  the  dwarf  habited  Pearl  come  to  hand  in 
December  or  January.  All  may  be  potted  in  a  compost  of  fibrous 
loam,  leaf  mould,  decayed  manuie  and  silver  sand. 
The  largest  bulbs  should  be  placed  singly  in  5-inch  pots,  and  the 
smaller  three  in  a  6-inch  pot.  Drain  tne  pots  efficiently  and  place  the 
bulbs  about  two-thirds  of  their  depth,  potting  firmly.  After  potting, 
place  at  once  in  bottom  heat  ranging  between  60°  r  nd  70°,  the  pots 
being  plunged  in  moist  cocoanut  fibre  refuse.  Give  a  gentle  watering, 
but  afford  no  more  until  growth  begir.s.  When  fairly  well  establi.-hed 
remove  the  pots  from  the  plunging  material  and  place  on  a  shelf 
near  the  glass  in  a  temperature  of  60°,  where  they  may  remain  until 
flowering  commences,  of  course  not  allowing  the  growth  to  touch 
the  glass,  esj  ecially  when  the  external  temperature  is  low.  A. 
greenhouse  temperature  is  sufficient  for  the  plants  when  in  bloom,, 
as  the  flowers  will  last  longer  in  a  cool  greenhouse. 
Bulbs  potted  in  February  and  not  wanted  to  blocm  quickly  may  be- 
placed  in  a  frame,  using  moifet  soil  in  plotting  and  not  watering.  Cover 
with  cocoanut  fibre  refuse  in  a  moist  condition  several  inches  above 
the  pots.  When  growth  begins  expose  the  plants  gradually  to  the 
light  and  give  an  application  of  water.  When  growth  commences 
to  extend  freely  the  plants  can  be  removed  to  the  greenhouse, 
watered  as  often  as  the  surface  soil  dries,  and  they  will  soon  flower. 
By  potting  at  intervals,  giving  the  treatment  suggested,  a  succession 
of  flowers  may  be  obtained.  The  blooms  are  always  invaluable  for 
bouquets  and  buttonholes.— E, 
