Ceratostigma plumbaginoides; was Colchicum byzantinum and friends
Jane McGary (Fri, 16 Oct 2009 09:33:27 PDT)
Jim McKenney wrote,
Ceratostigma plumbaginoides ramps like a champ here, and it
eventually invaded a clump of Sternbergia lutea. Now that's a
combination to love! Those two really sing well together. I'm
redoing big sections of the garden right now, and I'm looking around
for a place to prominently show off that pairing.
Because the leadwort emerges so late in our climate, extensive
plantings of it don't have much to offer early in the year. One way
to take advantage of that is to underplant the leadwort with early
blooming plants which are summer dormant. But to my tastes, an even
better way to take advantage of that space early in the year is to
underplant thickly with Lycoris. Their foliage will be up and busy
from late winter into late spring; by the time the leadwort kicks
in, the lycoris will be dying back.
Lycoris radiata, L. sanguinea. L. sprengeri (in other words, lower
growing sorts) and Sternbergia lutea (and if it grows in the garden
for you, Rhodophiala bifida) make for a merry show when blooming
over a thick mat of leadwort. This is also a great place for any
hardy Zephyranthes or Habranthus. And if your climate allows, this
is also a great way to grow Tigridia pavonia.
I wouldn't plant sternbergia with Ceratostigma ("leadwort") because
the foliage of the perennial is too tall and would interfere with the
proper character of the sternbergias (that is, the latter would grow
but would have to stretch inappropriately to rise above the
leadwort). Lycoris flowers poorly, if at all, in the Pacific
Northwest, probably because of the cool summer nights that result
from low atmospheric humidity, and the same is true of Zephyranthes
and Habranthus and Rhodophiala bifida. And, of course, Tigridia is
just a bedding annual here, unless one should have a remarkably
protected site. My choice for another season of flower in such a
planting is large daffodils in spring and hardy alstroemerias in
summer. The alstroemeria foliage is at its best before the
ceratostigma foliage develops. This plan does require several major
clean-up operations but I think that's manageable.
As for the color combination, when we think of that, we have to
consider the effect of the foliage too -- ceratostigma is far more
leaf than flower, and here the leaves color beautifully in fall.
Perhaps one could add some foliage that would moderate the color
relationships, such as a pale tan clump-forming sedge (also beautiful
in spring with tulips). Moreover, although the larger colchicums
(unless white) are all in the same general color range, there is
variation, particularly since many of them have prominent white central zones.
A combination that is enjoyable today is gray-leaved mat-forming
thyme with some of the little Colchicum species, notably C.
procurrens, which seems quite at home in an unirrigated terrace with
a deep sand and gravel topping. The fall crocuses are popping up in
the front lawn, where ants apparently have transported the seeds of
Crocus pulchellus and C. kotschyanus. A crocus that can be grown in
taller vegetation is C. speciosus, a very hardy one that tolerates
summer water. Many crocuses grow in grazed grassland in nature, and I
feel that the density of the sod helps protect the corms against rodents.
This exchange is a perfect example of why the recommendations in
garden books have to be evaluated against local experience. Just as
it might never occur to a writer from Jim's area (the mid-Atlantic
coastal region) not to recommend Lycoris for general use throughout
North America, the same writer might never consider using Pacific
coastal species of Alstroemeria, which may not flourish where
subjected to summer rainfall.
Jane McGary
Northwestern Oregon, USA