Evening star. [volume] (Washington, D.C.) 1854-1972, 1948-08-01
Blue Flowers
Lend Distance
InGardens
By w. n. Younamon

in the plant world. They appeal
to some more than to others, but
for their landscape value they merit
greater consideration. Blue gives
the effect Of distance, which is often
desirable in the small shrub border
and Is useful as contrast to other
colors. Blue makes an excellent
specimen color in many situations.
True blues are not common in the
plant world. There are a few, such
as the blue hydrangea, the blue
spirea (Caryopteris) and some OF
the lilacs, but they are often more
purple than blue. The smoke tree
(Rhus cotinus) has grayish blue
cast. Among many of the blue
puppies we have such interesting
shrubs as buddleia butterfly bush)
purple broom (Cytisus purpureus)
shrub bushclover Gespedeza and
the mintshrub (Elsholtzia).
81 The most commonly grown OF the
blue-fowered shrubs is, of course
the blue hydrangea, although this
is about as far North as it can be
grown out of doors. Frequently
called the shiny-leaf hydrangea,
we buy them as potted pink-f1ow-
cred plants from the florist. When
through Towering at Easterttme,
we plant them out of doors. In our
acid soils they produce flowers OF
varying shades of blue.
Moisture, Shade Desired.
The blue hydrangea needs album
dant moisture for good growth, is
partial to full shade and needs a
soil we'll supplied with leaf mold Or
peat moss. In a too-well-protected
situation they frequently lose their
flower buds. Do not cut the shoots
back in the spring, but thin them
out, removing the weakest ones for
strong growth and large flowers.
Blue and purple lilacs are prob
ably as widely planted as the by
drangeas but there Is less use OF the
bluer sorts-lilac and purple. Not
only are there excellent blues and
blue puppies as well as lilac shades
among the Syringa vulgaris hybrids
(and the so-called French lilacs)
but several Of the species provide
these colors.
Lilacs prefer a sunny situation
and one that has fairly rich soil.
They like q sweet soil although they
are tolerant and will do fairly well
in an acid soil. The biggest handi-
cap to lilac growing in this area
is the oyster shell scale, although 1t
is easily controlled by spraying with
q dormant-strength lime-sulphur
solution in the early spring. Re-
moving a portion of the suckers
which spring up from the roots
throws the plants strength into
flower buds.
The shrub althea (Hibiscus syria
cus) is another widely planted
shrub or small tree-10 to 20 feet
that has purple-colored flowers.
Some of the named varieties are
blue-purple. 1t is easily grown and
will tolerate shade. The Towering
season, July-August, makes it de-
sirable as a summer bloomer, but,
unfortunately, the japanese beetles
like them. 1t may be trained as
hedge plant or allowed to grow into
a small tree.
Rhododendrons Popular.
The purple rhododendrons are
too well known to need more than
passing mention here. Most of the
purple varieties like partial shade
but will do very well in sun If prop
erly mulched. These shallow-rooted
plants need a cool root run II they
are to thrive in this area.
ONLY a few gardeners have tried
the blue spirea (Caryopteris icanaD
a delightful, low growing shrub with
violet-blue flowers in September.
While this shrub Is often frozen
back during our winters 1t is seldom
killed except in poorly drained soils.
The freeze injury prompts garden
ers to prune the tops back, some
thing they should do anyway. Give
this plant spot in the perennial
border where its broad head OF
blue flowers will make a most in
teresting display in the late summer.
Occasionally one sees the hazy
purple bloom of the smoke tree in
this area. The smoke tree (Rhus
cotinus) grows to IS or 20 feet in
this area, likes sunny situation,
and does we'll in the usual garden
soil.
Many gardeners have grown one
or more varieties of the butterfly
bush CBuddleia) and find them sat
isfactory for display and for cutting
There are many varieties on the
market, but the species B. david
and the variety lie de France are
best known for their lilac and
purple flowers. The butterfly bush
prefers sun and does well In any
garden soil. 1t should be pruned
rather severely each spring If it is
to be kept compact, avoiding bare
leggedness which comes with ne
elect Of the pruning shears.
Rarer Blue Flowers.
Among the less we'll known of the
-flowered shrubs we might
mention the purple bushclover
Gespedeza formosa). 3foot shrub
that flowers in late summer. The
purple and the bicolor, or shrub
bushclover Il. bicolor) may be used
as a foreground planting in the
sunny shrub border or as specimen
shrubs. Even though they may
freeze back to the ground in severe
winter they will still produce an
excellent rosy-purple display in
August and September.
Still other shrubs belonging in
this group that seem to be worth
trying are the lilac chaste tree
(Vitex agnus-castus), summer
towering shrub growing to 10 feet
In a sunny situation: the Hartwig
locust CRobinia hartwigD, with rosy
purple flowers in July; the purple
broom (Cytisus purpureus), a pros
trate grower with purple bloom that
appears in May, seems better adapt
ed to the rock garden than to the
border: the Indigo bush (Amorpha
microphylla) is a low grower with
purple flowers in June-July, and
the mintshrub (Elsholtzia), whose
red-purple flowers are borne on a 8
,r foot shrub in September.
The mintShrub properly belongs