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March  26,  18§6, 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
expansion  by  heat  and  contraction  by  cold  to  its  limit,  a  few  degrees 
above  freezing  point,  when  this  order  is  reversed,  and  with  a  cube 
of  ice  produced,  say,  by  20°  of  frost,  will  continuity  or  an  additional 
10°  or  20°  result  in  further  expansion  ?  I  believe  not.  If  this  was 
the  case  it  would  do  much  to  explain  the  higher  death  rate  in  the 
vegetable  kingdom  experienced  under  these  cumulative  conditions. 
The  action  of  frost  on  hardy  plants — that  is,  plants  which  have 
proved  themselves  hardy  under  any  extremes  our  own  climate 
subjects  them  to — proves  their  pre-eminent  adaptability  to  that 
total  suspension  of  all  vital  functions,  with  their  inherent  power  to 
resume  them  uninjured.  Whereas,  per  contra,  amongst  the  so-called 
hardy  plants,  trees,  shrubs,  or  what  not,  to  what  cause  must  we 
attribute  the  mortality  entailed  by  a  winter  of  abnormal  severity  ? 
Here  the  question  arises,  Do  we  draw  conclusions  from  reliable 
data— viz.,  under  the  normal  conditions  of  an  ordinary  winter  do 
they  become  actually  and  absolutely  frozen  ? 
Again,  what  are  the  frost-resisting  qualities  of  the  cellular 
tissue  and  their  component  fluid  matter  ?  In  this  case  we  are  not 
dealing  with  water  pure  and  simple,  for  at  this  season  of  rest  water, 
or  the  form  of  it  elaborated  into  sap,  must  be  least  in  evidence. 
Then,  it  may  be  asked,  is  this  fluid  matter  contained  in  the  cells  of 
a  higher  freezing  point  than  water,  varying  in  power  according  to 
different  species  of  plants  ?  Granted  that  such  is  the  case,  whence 
the  injury  or  mortality  under  more  intense  frost,  and  wherein  is 
the  susceptibility  to  its  influence  ?  Is  it  that  the  cells  are  ruptured 
by  expansion  ?  This  phase  of  the  subject  opens  up  a  wider  field  of 
thought  and  inquiry. 
Atmospheric  pressure  is,  I  think,  a  factor  which  may  now  be 
included,  but  it  is  a  very  intangible  subject  to  grasp.  Aware,  as  we 
are,  of  the  supportive  power  of  our  atmosphere,  and,  also,  of  the 
variations  in  density  as  recorded  by  the  barometer,  it  is  possible 
that  we  have  here  an  influence  not  to  be  ignored.  The  coming  and 
going  of  frost  being  usually  accompanied  by  fluctuating  pressure, 
there  appears  to  be  some  reason  for  surmising  that  these  changes, 
sudden,  perhaps,  have  a  contingent  bearing  on  the  matter. 
The  simple  question  “  Why  do  hardy  plants  come  through  the 
ordeal  without  injury  ?  ”  may  be  as  simply  answered,  “  Because  they 
are  hardy.”  But  why  are  they  hardy,  and  in  what  does  their 
hardiness  consist  ?  Days,  weeks,  or  months  of  frost  makes  no 
difference  (to  the  perfectly  hardy  subject  be  it  understood),  nor, 
indeed,  should  it,  for  in  the  total  suspension  of  animation  time  is, 
practically,  lost  sight  of.  Lily  of  the  Valley  is  now  held  back  for 
months,  and  if  we  are  able  to  deceive  Nature  by  artificial  refrigera¬ 
tion  for  months,  why  not  for  years  ?  Anyway,  I  hope  these  powers 
of  endurance,  if  dormant  life  can  be  said  to  endure,  will  be  tested 
by  those  who  have  the  facility  to  do  so.  Hardy  plants  are, 
presumably,  adapted  to  those  conditions  of  frost  by  their  con¬ 
stitutional  elasticity — literal  elasticity  of  the  cellular  tissue  to 
sustain  the  change — the  recall  to  active  life — without  injury,  and 
this  power  may  be  more  or  less  absent  in  so-called  hardy  plants. 
That  we  must  look  for  the  chief  cause  of  injury  in  rupture  of 
the  cellular  tissue  is,  I  think,  evidenced  by  the  long-delayed  effects 
noticeable  amongst  evergreens,  Roses,  or  similar  subjects.  Not 
until  a  fuller  demand  is  made  by  Nature  upon  them  when  arriving 
at  the  period  of  active  growth  do  we,  as  a  rule,  become  aware  of  the 
actual  damage  ;  then  the  disorganisation  is  apparent  in  the  collapse 
which  takes  place. 
The  action  of  light  in  its  relation  to  frost  is  another  matter  for 
consideration.  Light  as  a  decomposing  agent  possesses  influence 
better  known  than  understood,  and  with  frost-bitten  subjects  we 
find  that  its  exclusion  minimises  the  injury.  It  is  well  known,  as 
it  was,  indeed,  a  generation  since,  that  the  gradual  extraction  of 
frost  by  the  exclusion  of  light  with  a  liberal  douche  of  cold  water, 
is  the  simplest  and  safest  remedy  to  employ  where  tender  plants  in 
frames  or  houses  should  unwittingly  be  subjected  to  the  ordeal. 
Some  thirty  years  since  I  was  witness  of  a  case  in  point  where  the 
whole  stock  of  a  greenhouse  was  frozen  stiff,  root  and  branch. 
Prompt  attention  by  these  measures  was  given,  and  what  at 
first  sight  looked  like  a  calamity  eventually  proved  to  be  of 
comparatively  little  moment,  but  few  of  the  occupants  being 
seriously  injured  and  fewer  still  killed. 
In  the  course  of  a  gardener’s  life  a  variety  of  experience  is 
afforded  by  the  subject,  but  this  being  chiefly  confined  to  the 
effects  of  frost  rather  than  to  its  action,  the  observation  is  but 
desultory  and  provides  no  reliable  data  for  analysis.  The 
refrigerating  chamber  should  be  a  valuable  laboratory  for  scientific 
research,  providing  immunity  from  many  disturbing  influences 
accompanying  open-air  observation.  Under  those  conditions  the 
intensity  of  abnormal  frost  may  not,  obviously,  be  reproduced,  but 
its  duration,  which  is  hardly  of  secondary  importance,  should  be  of 
distinctive  value  in  experimenting.  Sections  of  root  or  branch 
would  doubtless,  by  microscopic  examination,  yield  data  explanatory 
of  things  as  yet  but  imperfectly  understood,  or  of  which  we  are  in 
ignorance.  Moreover,  the  subjecting  of  plates  of  glass  on  which 
condensed  moisture  has  been  deposited  when  submitted  to  the 
action  of  various  currents  of  air,  or  waves  of  light,  might  probably 
reveal  the  more  subtle  of  secret  workings. 
In  the  dynamic  expansive  power  of  frost  in  its  relation  to  soil 
we  have  a  potent  agent  for  good,  the  aeration  of  retentive  soils 
by  this  means  having  a  beneficial  influence  which  may  be  super¬ 
ficially  overlooked,  though  the  general  good  derived  is  admitted. 
Under  this  phase  of  the  subject  the  question  is  presented  whether 
we  may  not  have  an  influence  working  out  far-reaching  ends, 
farther  than  usually  accredited  to  it.  There  is,  I  know,  a  vague 
foreboding  among  the  weatherwise  that  an  open  winter  is  followed 
by  an  uncongenial  spring.  And  not  without  reason,  which  may  be 
more  clearly  defined  in  supposing,  rightly,  I  think,  that  during  the 
absence  of  frost  radiation  from  the  earth’s  store  of  heat  is 
constantly  going  on.  Frost  admittedly  cools  the  ground,  bnt  only 
so  far  as  it  penetrates  ;  it  must  then  seal  up,  during  its  presence, 
the  thermal  stores,  whereas  the  constant  radiation  during  an  open 
winter  can  be  but  an  expense  of  means  to  the  end  of  an  uncon¬ 
genial  spring  with  its  May  frosts,  the  bete  noir  of  a  gardener’s  life 
at  that  season. — Invicta. 
CULTURE  OF  HOLLYHOCKS. 
The  Hollyhock  is  the  noblest  of  all  florists’  flowers.  Towering 
above  all  its  neighbours  like  a  giant,  and  in  almost  every  shade  of 
colour,  we  know  no  other  plant  that  could  take  its  place.  What 
other  could  give  such  a  bold  appearance  to  mixed  borders  ?  Its 
flowers  will  also  bear  a  very  favourable  comparison  with  most  florist 
flowers,  and  stands  of  its  cut  blooms  form  very  appropriate  com¬ 
panions  to  the  Dahlia,  not  only  on  the  exhibition  table,  but  in 
almost  all  positions.  In  fact  the  two  are  so  thoroughly  united 
together  in  my  mind  that  they  almost  seem  inseparable.  As  back 
lines  to  broad  flower  borders  they  are  in  my  opinion  unsurpassed, 
the  noble  bearing  of  the  Hollyhock  adding  to  the  massive  beauty 
of  the  Dahlia. 
It  forms  no  part  of  my  intention  in  the  following  notes  to 
trace  the  history  and  gradual  improvement  of  the  Hollyhock 
by  the  skill  of  the  florist.  It  is  quite  sufficient  for  my  purpose  to 
know  it  was  introduced  from  China — a  very  different  looking  plant 
to  what  we  have  it  at  the  present  day.  It  will  under  certain  con¬ 
ditions  endure  the  ordinary  winters  of  Britain — a  circumstance  I 
never  advise,  as  I  consider  it  quite  worthy  the  shelter  of  a  cold 
frame  during  the  winter,  and  that  is  the  only  protection  it  requires 
except  in  sharp  weather,  when  a  little  extra  covering  is  advisable. 
It  belongs  to  the  order  Malvaceae,  which  implies  that  the  plant 
requires  plenty  of  light  and  water. 
In  giving  my  method  of  successfully  growing  the  plant  I  will 
first  say  that  it  is  my  usual  practice  to  have  at  least  the  half  of  my 
stock  young  plants  every  year,  believing  they,  in  common  with 
many  other  plants,  produce  better  individual  blooms  than  do  old 
plants  ;  and  by  having  two  sets,  old  and  young,  the  period  of 
flowering  is  prolonged,  the  old  coming  earlier  into  bloom  than  the 
young  plants. 
For  many  years  after  becoming  a  grower  and  ardent  admirer 
of  the  Hollyhock  there  was  no  other  mode  known  to  me  of 
increasing  the  stock  except  by  cuttings  of  the  young  shoots,  and 
single  eyes,  before  the  stems  had  become  hard  in  the  autumn. 
With  cuttings  I  found  considerable  annoyance  at  times  through,  I 
believe,  my  anxiety  to  push  them  too  quickly  with  heat.  After  a 
