seems to be the month that’s reserved for
my favorite plants. Dwarf plumbago, Ceratostigma plumbaginoides,
has earned a place in my personal Plant Hall of Fame. While
it’s just now emerging from its winter’s nap, one of its finest
applications is as a cover for fading foliage of spring bulbs.
So if you’re feeling frustrated about those yellowing straps
of daffodil and tulip leaves, consider putting C. plumbaginoides in
your bulb bed. Its show is just beginning while the bulbs give
their final bows. The shallow root system of C. plumbaginoides won’t
interfere with your bulbs; the cultivation requirements are
similar; and as you’re feeding your dwarf plumbago, you’ll
be nourishing the bulbs for their repeat performance next spring.
photographs do this plant justice. The brilliant blue flowers
that emerge in late July and last until first
frost are absolutely electric without sidestepping into the
category of “garish.” They offer a true-blue complement to
the other robust colors offered by the late-summer stalwarts
of Northwest gardens. The foliage that precedes bloom is deep
green; as the flowers emerge, the leaves develop a rich bronze
cast that only deepens as the weather cools and the days grow
short. This plant is breathtaking under Acer palmatum ‘Crimson
Queen’, for the bronze tones of the dwarf plumbago match perfectly
the color of the small maple’s leaves as they droop down and
mingle with those amazing blue flowers. It’s a real “wow” and
unlike some serendipitous magic moments in our gardens, it’s
a perfectly dependable one that repeats every year.
As for the basics, C. plumbaginoides is
of short stature, about ten inches tall. It spreads slowly,
never invasively, and is suitable as a small-scale ground cover.
In fact, it is at its most attractive when massed, and much
less effective as a single specimen. Its ancestry is Mediterranean,
so it appreciates our dry summers. It actually does best in
less-than-perfect soil, although good drainage is essential.
It requires only moderate water and is not susceptible to pests
or diseases. Slugs actually avoid it, if you can fathom that.
It dies back completely during the winter, so the only clean-up
required is the shearing off of the old, dead stems before
the new growth emerges in late spring. This lovely plant is
fully hardy in Bellingham, although you might want to cover
it with a winter’s mulch if you live in the north county. Officially,
it can withstand temperatures as low as ten degrees below zero.
A regimen of regular care will keep it happy,
and it will survive some neglect without complaint. Its continuing
presence in my own garden attests to that. Grow it in almost
full sun where it can show to full effect. Spreading out from
under the spotty cover of a small lace-leaf maple is perfect.
Ceratostigma plumbaginoides really
demand much in return for the spectacular show it provides
every summer and fall. It belongs to a very tough family. I’ll
have to write more about the other members of the Plumbaginaceae
family in a future column—I’ve used up my allotted space for
this one. So stay tuned. And speaking of future columns, at
the mock clinic in April, one of the new Sprouts—my affectionate
if irreverent term for newly trained Master Gardeners—asked
how I choose which plants to write about. Lots of factors go
into my decision, including mixing the unusual with the familiar,
the easy-to-grow plants with more exotic ones, reviving old
standards and touting newcomers. I try to hang some text on
the season at hand, always remembering which plants work here
and which don’t. But it is most definitely a delight to respond
to reader requests. So, if there’s a plant you’d like to know
more about, or one you’ve found that you’d like to share with
others, please let me know. All suggestions are welcome. Just
let me know by phone or send me an e-mail at email@example.com,
and I’ll do a write-up on your favorite plant.