ON GROUPING ORNAMENTAL PLANTS. 
181 
in regular order and union, unless the form or colour of the plants blend or 
contrast pleasingly with those of surrounding groups. 
We are aware that in Arboretums, the trees are usually planted alone, so as 
to grow into handsome single specimens ; and that consequently what we have 
just said will hardly apply to them. But when we speak of groups, we do not 
restrict our meaning to those in which the plants are close together, or intermingle 
w^ith each other. They may be a considerable distance apart, so as to appear, 
when individually gazed upon, quite detached ; and yet, regarded comprehen- 
sively, they may compose what we call a group. Arboretums are of this latter 
nature, and we must ever object to the plantation of trees in running masses, 
without any consideration of their aspect. If the genera, or divisions of the 
larger ones, were placed at somewhat remote intervals, putting appropriate plants 
around and between them, our objections would be reduced to the inquiry how 
far any number of species of one genus would combine favourably. And we 
think that an arboretum, ranged along the sides of a lengthened drive, planting 
the different genera, with due respect to harmony, and to beauty of outline, at 
intervals, and filling up the interspaces with whatever would best associate with the 
particular tribes in either direction, would be a really admirable feature in an 
estate. 
For forming groups of shrubs, the same rule applies which we have laid down 
in relation to trees. There are many shrubby plants which are excellently adapted 
for planting in masses of one species, and others, of which a mixture of species or 
varieties is more desirable, but which do not need the aid of foreign genera to 
render their appearance favourable. Periwinkles, Tree Peonies, Yacciniums, 
Daphne Cneorum, several Genistas, Lavender, the common Savin, and numerous 
others, belong to the former class. To the latter may be referred Rhododendrons, 
Azaleas, Cistuses, Helianthemums, Berberises, &c. ; while Roses, Heaths, and 
plants of a like character, may be ranked with both tribes. 
Sometimes the peculiar soil or situation which shrubs require, has to determine 
the manner in which they are to be grouped; and, singularly enough, it is found 
that those demanding these peculiar circumstances, can be associated in a general 
mass with the greatest propriety, or will, for the most part, look well in masses of 
one species, or of the members of one genus. Of these, the tribe for which heath- 
mould and a somewhat sheltered spot are desirable, may be brought forward as 
examples. 
Cultivators scarceh;- seem yet to have appreciated shrubs at their full value 
for grouping purposes. They are commonly employed only at the margins of 
plantations to complete the slope from the trees down to the flower-borders or 
walks, or planted very sparingly as detached specimens. Their extreme suitable- 
ness for growing in beds, furnished with one or many species, and having no trees 
in their centre, nor herbaceous plants round the outside, is most strangely over- 
looked in the majority of places. In the secluded dells which may exist, or be 
