Foeniculum vulgare
‘Purpureum’
copper fennel
apiaceaeFeathery purple foliage; yellow-green
umbel flowers
3–4 ft. high; 1 1/2–2 ft. wide
Full sun
Blooms July–August
Zones 4–9
pruning Copper fennel is most often
grown in the perennial garden for its
ornamental foliage color and texture.
Some gardeners remove the flowers
while in bud to prevent flowering
altogether so as to not detract from the
foliar effect. Plants can also reseed
heavily, and preventing the plants
from flowering is a sure way to
eliminate this problem. But fennel
should really be permitted to flower,
because the small flowers serve an
important function in being the host
for beneficial parasitic wasps. These
wasps help control caterpillars, aphids,and other soft-bodied pests. Deadhead
fennel after all flowering is finished
and before seeds mature. Allowing a
small amount of seeding can mean
greater constancy of the plant in the
garden, as fennel are often short-lived.
Fennel foliage can also serve an
important function in the perennial
garden in that it provides larval food
for black and anise swallowtail
butterflies. In some years, this may
mean total defoliation of fennel by late
summer, in which case the bare stems
should be cut to the ground at this
time. The leaves hang limply from the
stems if hit by a heavy freeze, so
cutting down for the winter may be
preferred to spring pruning.
Care should be taken when working
with fennel because the plant’s juices
can cause phytophotodermatitis in
some individuals—this means that if
the juice gets on the skin and is
exposed to the sun a reaction will
occur, creating dark purplish discolor-
ation on the skin, which can developFoeniculum vulgare ‘Purpureum’