Polemonium caeruleum
Jacob’s ladder
polemoniaceae
Small blue flowers on spikes; pinnately
compound leaves
18–24 in. (10 in.) high; 18 in. wide
Part shade
Blooms June
Zones 3–7
pruning Cutting plants down to lush
basal foliage after all flowering is
finished may produce some sporadic
rebloom later in the summer. Stems
decline by late summer anyway, so
cutting them down early also keeps
the plants looking fresh. Plants can be
prolific seeders. If reseeding is not
desired, cut plants down before seed
has a chance to mature. Although
long-lived in the North, plants can be
short-lived in southern regions and so
allowing some seeding may be the
only way to ensure constancy of the
plant in such warmer conditions.
Leave the basal growth for the winter
and cut off any damaged material if
needed in the spring.
other maintenance Plants prefer
rich, moist, humus soil. They will take
some sun in cooler climates. Foliage
scorches in very hot, sunny locations,
requiring cutting back. Plants seldom
need to be divided, but if desired,
perform in late summer.Polemonium caeruleum