The  Turban  Sanunculuses  may  also  be  planted  in  autumn,  but
the  Persian,  being  rather  tenderer,  should  be  deferred  till  early
spring.  Ranunculuses  prefer  a  cool, 'sliglitly  retentive  soil,
but  the  drainage  must  be  efficient.  Watering  is  sometimes
necessary,  and  should  be  carefully  done.  Protection  from  frost
should  be  afforded,  or  the  foliage  and  inflorescence  will  suffer.
Another  condition  is  firmness  of  the  soil  around  the  roots.
6.  Culture  of  Annuals  and  Biennials,

Plants  of  annual  or  biennial  duration  possess  so  many  valuable
qualities  that  they  are  quite  indispensable  in  the  flower  garden.
Some  are  cherished  for  their  fragrance,  as  the  Sweet  Pea,
Mignonette,  and  Stocks ;  others  for  the  showiness  and  the  variety
of  their  brilliantly  coloured  flowers,  as  Poppies,  Zinnias,  and
Asters ;  others  for  their  diminutive,  compact  habit,  and  pro-
fusion of  flowers,  as  Leptosiphon  and  lonopsidium ;  others  for
the  duration  of  their  scarious  flower-heads,  as  Helichrysum
and  Waitzia ;  and  others  again  for  the  elegance  and  grace  of
their  inflorescence,  as  Humea  elegans  and  Agrostis  nebulosa.
A  large  number  of  perennials,  many  of  them  tender,  are  com-
monly treated  as  annuals,  and  flower  the  first  season.  The  fact
of  their  being  amenable  to  this  mode  of  treatment  is  usually
mentioned  under  the  description.  A  notable  case  in  point  is
the  Lobelia  Erinus,  a  difficult  plant  to  preserve  through  the
winter,  but  easily  raised  from  seed,  which  it  produces  in  great
abundance.  Annuals  are  of  the  greatest  service  for  filling  up
vacant  spaces,  or,  when  judiciously  selected,  for  growing  by
themselves  in  beds  or  borders.  Such  plants  as  the  China  Aster,
Zinnia,  and  Phlox  Drummondii,  make  very  effective  beds,  either
with  their  varieties  mixed,  or  in  separate  colours.      Another

QQ  2


59^  Cultivatiofi  of  Plants.
