7g 
They demand, in fact, hill air.” If this is so, and our experience 
with Gentians supports Farrer’s contention, what chance have we 
in Brooklyn of growing these aristocrats of the mountain tops? 
Occasionally we get a bloom on Gentiana acaulis, such mediocri- 
ties as G. cruciata and G. tibetica from time to time thrive lustily, 
but such happenings are of little moment compared to the glorious 
manifestations of which this race is capable. One handsome 
species, however, we may plant with good expectation of success, 
and that is G. septemfida, whose flowers of soft blue are produced 
from July to October. 
Other flowers that may be seen in the rock garden in July in- 
clude Campanula, Phytewma, Symphyandra, Horminum, and 
Minulus. 
August 
Most of the plants blooming in August are hold-overs from 
preceding months. 
The Balloon flower (Platycodon grandiflorum) starts its blos- 
soming career in late June and continues into August. Its dull 
blue flowers, balloon s 
—_" 
yaped in bud, are legion, and prodigal in 
their production of seeds, which, unfortunately, scatter and ger- 
minate freely, necessitating ruthless weeding of the seedlings if 
they are to be kept from monopolizing the whole rock garden. 
The var. Mariesti, dwarfer and less rampant, is to be preferred 
in the small garden. 
The Knotweeds (Polygonum) on the whole must be rigorously 
excluded from the rock garden. An exception is P. affine (P- 
Brunonis), a trailing species from the Himalayas which has at- 
atractive foliage and spikes of red flowers. We grow also P. 
alpinum (May, June) which, although its white, feathery panicles 
are beautiful, 1s to be viewed with suspicion because of its invading 
tendencies. 
An interesting little Tickseed (Coreopsis rosea) is now in bloom. 
It is native to the Eastern States from Massachusetts to Georgia. 
Perhaps some will cavil at this species being allowed in the rock 
garden, but its daisy-like, rosy flowers with yellow centers are 
welcome at this time and it does not look out of place. It attains 
a height of about eighteen inches. 
