PPDL Picture of the Week
June 29, 2020
Hyrdangea Flowers - Red, White, or Blue?
B. Rosie Lerner, Extension Consumer Horticulture
Hydrangeas are popular but can be challenging for
Indiana gardeners. There
are numerous species and cultivars that show amazingly diverse flowering characteristics,
especially color. Depending
on the species, cultivar and environmental conditions, the flowers may be pink
to red, blue to purple, cream to white, or some shade thereof.
gardeners are awestruck when they see a gorgeous blue-flowering hydrangea. Such a specimen is no
doubt one of the big-leaf hydrangeas, known botanically as Hydrangea
macrophylla , which has flowers that will be blue in acid pH soil, and pink in
alkaline pH soil. Since
this species typically flowers on old wood and is usually killed to the ground
in much of Indiana, this plant often disappoints as it produces abundant new
foliage but no flowers. If
it does manage to bloom, much of Indiana has alkaline soil, so flowers are more
likely to be pink unless the gardener treats the soil to lower pH
substantially. There are
some more recently bred cultivars that bloom primarily on old wood but have the
ability to produce some blooms on new wood including ‘Endless Summer’,
‘Bloomstruck’, ‘Twist ‘N Shout’, and “Let’s Dance’.
species that flower mostly on new wood include H. paniculata and H.
arborescens, and have white blooms. For
more information on the different types of hydrangeas in Indiana, see https://www.purdue.edu/hla/sites/yardandgarden/hydrangea-popular-but-confusing/