134 
JOURNAL  UN  HORTICULTURE  AND  COTTAGE  GARDENER. 
Fcbruar}’  12,  1903. 
grown,  and  such  land  is  then  regarded  as  worn  out  and 
unprofitable.  The  fact  is  that  usually  only  the  soluble  food 
is  e.xhausted,  the  larger  portion,  in  insoluble  form,  is 
still  ready  to  respond  to  good  culture,  by  which  it  may  be 
gradually  brought  to  such  a  condition  as  will  result  in  profit¬ 
able  return.  We  mean  by  plant  food  those  constituents 
Avhich  exist  in  the  soil,  or  are  supplied  in  manure,  which 
promote  the  growth  of  crops.  As  already  mentioned,  the 
amount  of  soluble  material  in  soils  is  very  small,  so  Ave  find 
that  the  quantity  of  soluble  plant  elements  actually  taken 
up  by  garden  A’egetables  is  small  as  compared  Avith  the  full 
bulk  of  a  crop  ;  but  it  is  these  soluble  constituents  Avhich  are 
the  most  necessary ;  in  fact,  so  much  so  that  Avithout  them, 
or  even  any  one  of  them,  vegetables  simply  fail  to  make 
satisfactory  progress.  It  is  Avell,  therefore,  to  accustom 
ourselves  to  z’egard  manures  of  Avhatever  form  as  so  much 
nitrogen,  potash,  and  phosphoric  acid. 
Nitrogen  is  often  called  “  ammonia,”  probably  because 
the  Avord  ammonia  means  a  Avell-knoAvn  substance  to  most 
gardeners,  AA'hile  nitrogen  is  an  unfamiliar  term.  Ammonia 
is,  however,  a  compound  of  nitrogen  and  a  gas  called 
hydrogen.  The  hydrogen  is  of  comparatively  little  value  in 
plant  life.  The  nitrogenous  plant  food  in  fertilisers  rarely 
ever  contains  any  actual  free  ammonia ;  it  is  ahvays  better 
therefore,  to  adopt  the  Avord  nitrogen,  and  become  familiar 
Avith  it.  Nitrogen  is  a  gas,  and  Avhen  taken  up  by  plants  is 
generally  understood  to  be  combined  with  a  gas  called 
oxygen,  forming  nitric  acid.  When  this  nitric  acid  is  joined 
to  other  substances  found  in  the  soil,  such  as  lime  or  potash, 
a  product  is  formed  called  either  nitrate  of  lime  or  nitrate  of 
potash.  And  it  is  these  Avhich  constitute  the  most  useful 
forms  of  plant  food  in  fertile  soils. 
Another  very  important  constituent  in  garden  soils  is 
humus.  Noav  humus  is  a  term  applied  to  partially  decom¬ 
posed  vegetable  matter,  Avhich  results  from  the  gradual 
decay  in  the  soil  of  roots  and  other  parts  of  plants  ;  and 
also  from  the  organic  matter  of  applied  farmyard  dung. 
Though  not  in  itself  a  direct  form  of  plant  nourishment, 
humus  is  nevertheless  one  of  the  most  important  con¬ 
stituents  of  all  fertile  garden  soils.  One  of  the  reasons  for 
the  value  of  humus  is  that  it  acts  as  a  natural  storehouse 
and  conserA’ation  of  nitrogen,  Avhich  is  the  most  expensive  of 
all  plant  foods  Avhen  it  becomes  necessary  to  purchase  it  in 
commercial  fertilisers. 
When  humus  is  abundant  in  the  soil  it  is  usually  asso¬ 
ciated  Avith  a  liberal  supply  of  nitrogen,  and  it  has  been 
noticed  that  the  amount  of  humus  present  gives  an  excellent 
indication  of  the  quantity  of  organic  nitrogen  the  soil  con¬ 
tains.  It  has  also  been  observed  that  as  the  humus  dis¬ 
appears  the  nitrogen  goes  Avith  it.  Humus  also  proAudes 
considerable  quantities  of  mineral  food  necessary  for  the 
groAA'th  of  garden  vegetables.  There  is  a  continual  process 
of  decay  going  on  in  the  soil  during  the  Avarm  days  of  spring 
and  summer,  so  that  the  constituents  of  the  humus  gradually 
become  available.  Humus  further  increases  the  power  of 
soils  to  hold  moisture,  Avhich  is  one  of  the  most  important 
functions  in  a  garden. 
Since  all  the  plant  food  presented  by  the  soil  must  be 
taken  up  by  the  A’egetables  in  solution,  the  amount  of  Avater 
required  by  succulent  vegetables  is  enormous.  For  every 
ton  of  dry  substance  produced  in  garden  crops  it  is  esti¬ 
mated  that  about  325  tons  of  Avater  are  required.  Hence  it 
is  clearly  seen  that  several  hundreds  of  tons  of  Avater  are 
'needed  on  each  acre  of  land  to  produce  a  single  crop  of 
garden  vegetables. 
The  folloAving  table  shoAvs  the  actual  amount  of  plant 
food  abstracted  from  an  acre  of  land  by  the  groAvth  of  an 
average  crop  of  each  of  the  vegetables  enumerated  :  — 
Vegetable  Crop. 
Nitrogen. 
Potash- 
Phosphoric 
Acid. 
Its. 
lbs. 
lbs. 
Cabbages 
114 
129 
23 
Cue  umbers  ... 
112 
168 
84 
Lettuce 
69 
111 
21 
Onions 
67 
48 
19 
Beets 
43 
79 
16 
Potatoes 
30 
41 
10 
Turnips 
21 
5 
8 
Asparagus  ... 
12 
12 
4 
Tomatoes 
11 
6 
8 
Caulifiowers 
25 
15 
7 
The  foregoing  figures  relate  only  to  those  portions  of  the 
crop  Avhich  are  usually  sold  off  the  land — the  tops,  leaves, 
stems,  &:c.,  not  being  counted,  as  they  are  supposed  to  go 
back  to  the  soil  as  manure  of  one  kind  or  another.  If  the 
refuse  portion  does  not  go  back  to  the  soil  then  the  actual 
drain  of  plant  food  in  groAA'ing  garden  vegetables  must  be 
much  rhore  than  the  figures  shoAA^  Further,  if  the  refuse  is 
burnt,  all  the  nitrogen  is  destroyed  and  lost,  only  the 
potash  and  phosphoric  acid  remain.  The  table,  hoAvever, 
is  extremely  useful  as  pointing  out  that  a  certain  amount 
of  nitrogen,  Avith  certain  other  amounts  of  potash  and  phos¬ 
phoric  acid,  must  be  used  in  manure  if  a  balance  is  to  be 
kept  in  the  plant  food  and  satisfactory  crops  of  A’egetables-- 
are  to  be  groAA’n.— J.  J.  Willis,  Harpenden. 
Herbaceous  Psonies. 
These  are  amongst  the  most  beautiful  of  hardy  plants,  and 
are  not  fastidious  in  regard  to  soil  or  position.  When  asso¬ 
ciated  with  other  of  our  garden  favourites,  such  as  Liliura:'. 
speciosum,  var.  L.  auratum  ;  Michaelmas  Daisies  ;  Delphi¬ 
niums;  Kniphofias,  Lobelia  fulgens  or  Gaillardias,  they  are 
most  effective.  Or  what  is  more  beautiful  than  the  bright- 
green  foliage  of  Daffodils  contrasting  -with  the  young  grOAvth 
of  the  Pseonies  in  its  mantle  of  carmine  in  spring?  And’: 
again,  in  late  summer  and  autumn,  Avhen  tinted  leaves  are 
so  much  in  request  for  lending  colour  in  churches  at  harvest 
festivals,  or  for  vases  for  table  decoration,  the  Pseony  foliage 
is  as  useful  as  the  Beech,  Guelder  Kose,  KoAvan,  Berberis, 
or  the  Oak.  The  various  shades  of  purple,  green,  and 
crimson  change  as  the  season  advances,  and  the  foliage  is- 
always  appreciated. 
Few  hardy  plants  have  a  wider  gradation  of  colour.  Every 
conceivable  shade  is  represented,  from  pure  Avhite  to  deep 
pink ;  from  rose  to  deep  crimson  and  shades  of  purple,  and 
many  approach  to  soft  yellow  and  primrose.  Nor  must 
fragrance  be  overlooked.  The  delightful  perfume  emitted  by 
many  of  the  new  hybrids  is  equal  to  the  Tea-scented  Boses. 
The  old  European  varieties  (P.  officinalis)  in  the  double, 
semi-double  and  single  forms  are  the  first  to  floAver,  expand¬ 
ing  their  huge  blossoms  in  May,  and  are  closely  folloAved  by 
the  beautiful  hybrids  of  P.  albiflora  or  Chinese  sorts,  with 
their  huge  and  handsome  double  or  single  flo Avers,  in  June. 
Their  culture  is  simple.  They  thrive  in  any  ordinary 
garden  soil  or  situation  in  all  parts  of  the  country  when  given- 
the  necessary  surface  mulch  in  autumn.  If  on  dry  soils,  they 
should  be  supplied  Avell  Avith  water  during  hot  dry  Aveather. 
They  best  like  a  moist  loamy  soil,  deeply  trenched,  adding, 
plenty  of  Avell  rotted  coav  manure  in  the  operation. 
After  planting,  they  are  greatly  benefited  by  a  top¬ 
dressing  of  rotted  manure,  which  should  be  applied  annually, 
to  be  lightly  forked  into  the  surface  about  October  or 
November. 
Planting  is  best  done  during  October  or  NoAember,  AA'hen-- 
a  feAv  flowers  may  be  expected  the  folloAA'ing  season.  They 
pjay,  hoAvever,  be  planted  successfully  any  time  up  to  March 
or  April,  and  given  copious  supplies  of  liquid  manure  twice 
a  Aveek  during  the  summer. 
Varieties. — A  few  kinds  of  P.  albiflora  of  distinguished 
merit  to  make  a  good  selection  are  as  follows  : — June  floAver- 
ing :  Lady  Carrington,  bright  pink,  A’ery  fine  ;  Vicomte  de 
Fonceville,  pink  with  Avhite  frill ;  Gloire  de  Patrie,  bright 
rose,  large  full  double  floAvers  ;  Josephine  Parmentier,  rose, 
pink  centre  ;  Lady  Leonora  BramAvell,  soft  rose,  very  large 
and  full ;  Countess  Clancarty,  blush,  centre  primrose  ;  Dela- 
cour  Verhille,  pure  Avhite,  large  handsome  floAvers,  petals 
very  broad  ;  Festira  Maxima,  snoAA-y  Avhite,  large  ;  Solfaterre, 
primrose  yellow,  very  handsome  ;  La  Tulipe,  AA’hite,  laced' 
crimson,  very  beautiful ;  Bose  d’Amour,  blush,  deliciously 
Bose  scented  ;  Eugene  Verdier,  AA’hite,  centre  blush,  very 
large  ;  Madame  de  Galhan,  soft  pink,  large  and  of  beautiful 
form  ;  John  Fraser,  cerise,  strongly  rose-scented  ;  Adelaide 
de  Lache,  deep  rose,  tipped  Avhite ;  Lord  Salisbury,  rich 
crimson  ;  Marshal  MacMahon,  rich  carmine  ;  Superbissima, 
large,  very  full  carmine  floAA’ers  ;  Louise  Van  Houtte,  purple 
.  crimson  ;  and  Edward  Simmons,  rich  crimson. 
The  Chinese  single  Pseonies  (A’arieties  of  P.  albiflora} 
appeal  to  many  more  than  do  the  double  forms,  probably  on 
account  of  the  great  contrast  between  the  petals  of  various 
shades  and  the  beautiful  gold  boss  of  stamens. 
The  May-floAvering  European  species  and  A’arieties  in  both 
the  double  and  single  forms  are  exceedingly  handsome,  but 
lack  that  fragrance  so  prevalent  in  the  Chinese.  The 
varieties  of  officinalis,  arietina.  anoniala,  decora,  peregrina, 
and  tenuifolia  deserve  a  place  in  every  garden. — W.  L. 
