Ceratostigma plumbaginoides; was Colchicum byzantinum and friends

Jane McGary janemcgary@earthlink.net
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

More information about the pbs mailing list