CHAPTER XV
 

                     Dwarf Trees  and Shrubs.



There are many places in the garden where  dwarf shrubs—shrubs, that

is, which never get more  than  3 ft. high, or take many years to do so—

are almost indispensable.   In the  Rock Garden, for  instance, they  are

of great value as giving diversity, shelter, and winter-furnishing without

encroaching upon or interfering with the regular occupants.  In places,

too, where plants are wanted not so tall as  to  obstruct the view, such as

in front of windows  or alongside low terrace walls, naturally dwarf shrubs

are infinitely to be  preferred to taller, stronger-growing ones, continually

kept low by cropping over with knife or shears.   They are also useful in

small formal arrangements.

   Besides those  shrubs whose dwarfness  is  a natural  and specific

characteristic, there are numerous others well known in gardens, in which

it is an abnormal one.  Trees long  in cultivation very frequently produce

dwarf sports and varieties as well as fastigiate and pendulous ones.  They

mostly retain their dwarfness  after being propagated by  cuttings  or by

grafting, and are  usually distinguished  by such names as nana, pumila,

dumosa,  and pygmasa.    The  common spruce,  one  of the  giants of

European  forests, is very prolific  of dwarf varieties; they occur  also

among other conifers in the Scotch  pine, Weymouth  pine,  Douglas  fir,

yew, silver fir, Corsican pine, black spruce,  common juniper and savin,

Lawson cypress  and  Cryptomeria japonica.   Some  of these  forms,

although sprung from trees naturally 100 to 200 ft. high, will  take twenty

years to grow 1 yard high.

   The dwarf varieties  of deciduous trees  are, as  a rule,, more vigorous

in growth  than the evergreens,  and not so well adapted for the special

places mentioned above.  They occur in the field and Norway maples,

Mahaleb,  and  gean cherries,  Catalpa  bignonioides,  Viburnum Opulus,

wych elm, common ash, white poplar, Robinia Pseudacacia, hawthorn, etc.

The   dwarf hawthorn (Cratcegus monogyna var. semperflorens). flowers

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