Fall-flowering Bulbs
Gardeners generally associate bulbs with springtime displays of
tulips, daffodils, hyacinths and crocus. However, some bulbs
actually begin to flower in fall, just as most plants are going
dormant.
The best known and earliest blooming of the fall-flowering bulbs
are Colchicum. Commonly referred to as the autumn crocus
or meadow saffron, colchicums are not related to crocus at
all, but are actually members of the lily family.
Beginning in mid-September and continuing into early November,
colchicum produce large, goblet-like blooms in shades of pink,
violet or white. In spring, colchicums offer relatively large,
broad leaves which are, unfortunately, a favourite food source for
slugs and snails.
There are quite a number of suitable colchicums for Newfoundland,
but they are often hard to find locally, so mail-order nurseries
are the best source. Species that do well include Colchicum
autumnale, C. speciosum, C. byzantinum and C.
agrippinum. Hybrids include ‘Autumn Queen’,
‘Lilac Wonder’, ‘The Giant’, ‘Violet
Queen’ and the double-flowered ‘Waterlily’.
Another increasingly popular group of fall-flowering bulbs is the
true autumn Crocus, relative of the typical spring crocus.
The earliest species bloom in late September, while other varieties
may not bloom until December; during mild falls I’ve actually
picked autumn crocus
on Christmas Day! Like their spring-blooming cousins,
fall crocus produce narrow, grass-like leaves in spring. Although
there are some dozen species of autumn-flowering crocus only a few
are hardy in our area. The most common and readily available is
Crocus speciosus, with purple-blue flowers from late
October till December. Crocus kotchyanus, C.
longiflorus, C. pulchellus, C. medius and C.
nudiflorus are other species that may be tried.
The other fall-flowering bulb, Cyclamen, is perhaps the
most dainty of the fall bloomers, offering a profusion of pink or
white flowers shaped vaguely like a shuttlecock. They bloom from
late August through early November. Unlike crocus or colchicum,
cyclamen produce their leaves just before, during or just after
flowering. These leaves stay green through the winter months and do
not disappear until July. Their leaves are often attractively
marbled light green to silvery over a dark green background. The
most popular species is Cyclamen hederifolium, but perhaps
the loveliest is C. purpurascens.
All of the mentioned bulbs are hardy in zone 5. Provide them with a
moderately fertile, well-drained soil (a heavy wet soil will
quickly cause them to rot). When first planted, generally in
September or even August if possible, the addition of bonemeal or a
high phosphorous fertilizer, is beneficial. In early May, the
addition of a general garden fertilizer or good compost will
further add to the plant’s longevity. As with the spring
bulbs, allow their foliage to die down naturally so the bulbs can
accumulate the reserves necessary for future bloom.
Autumn crocus, colchicum and cyclamen are ideal for the rock garden
where their fall flowers are easily seen among the other
low-growing plants. While the leaves of crocus and cyclamen are
relatively tidy, colchicum foliage is so large and floppy, that
many gardeners find them 
unsightly in the rock garden. One exception is C.
agrippinum, whose foliage is relatively small and an
interesting grey-green colour. This species also offers checkered
pink flowers, a unique feature among colchicum.
Crocus and colchicum are also suitable for interplanting among low
groundcovers such as periwinkle, creeping jenny, lily-of-the-valley
or bugleweed. The advantage of this setting is that the
groundcovers prevent autumn rains from splashing mud onto the
flowers. True autumn crocus may be naturalized in lawns as long as
the foliage gets a chance to ripen before the first spring mowing.
All three groups also lend themselves to woodland settings as they
can tolerate dappled shade (cyclamen actually prefer
part-shade).
At one time, gardeners bought their bulbs in fall and had to wait
until spring to enjoy the blooms. By growing some fall-flowering
bulbs, the reward is much more immediate.
Todd Boland
Research Horticulturist
