ALPINAS AND MACROPETALAS (The Atragenes)
These are generally the earliest of the hardy clematis to flower in
spring. They are very tough and will accept situations which are
unsuitable for other varieties but they will not tolerate boggy areas or
wet feet in the winter. Most are compact, under 10’, have attractive
foliage and frequently produce some bonus flowers later in the year. The
flowers are small, 1- 2 ½”, nodding single in alpinas, double for
macropetalas. The seed-heads are very silky and ornamental. Because of
their compact growth habit, they are good choices for gardens with
limited space or for container culture. Best planted in northern or
eastern exposures, this is particularly important in areas where there
is a lot of thawing and freezing in winter, or where late spring frosts
are common. While they flower well in shade, the colors are clearer in a
sunny exposure. Like other fibrous-rooted clematis, they resent
disturbance, so leave those root-balls alone when planting!
This group includes some of the most vigorous clematis. They flower
mainly in early spring, with masses of small flowers cascading from
wherever they’re growing. Flowers are 1 ½” – 2” diameter unless
specified otherwise. While the montanas are root-hardy to
Zone 5, they are not reliably bud-hardy so use caution. They can be
damaged by late winter thawing and freezing in these areas, so if
possible give them a northern exposure, avoiding western winter sun.
Here in MA, montanas are generally hardy south of Boston, iffy north of
the city where they may succeed for a few years and then get nailed to
the ground one winter. Where they can be grown successfully, they are
ideal for covering large areas in a short time, and for growing on trees
or pergolas. They are not suited for the small garden or container
culture. Because they flower on the previous season’s growth they are
usually left unpruned or pruned to tidy only. Should they get out of
hand or need to be restrained, prune immediately after flowering in
spring to allow new growths to mature for next year’s flowers. Since
they are so vigorous they are best grown as specimens and not in
combination with other types of clematis. The fragrance of the scented
varieties will be most pronounced when they are planted in full sun.
Also, for those of us who live in the Frozen North, do bear in mind that
the maximum height achieved by these plants may be substantially less
than the norm.
The clematis in this group are not nearly well-enough known or used.
They are all clump-forming, herbaceous (i.e. they die back to the ground
each winter), short growers,
with heights ranging from 2’ to 6’, non-clinging, with clean foliage.
Flowers are broadly
campanulate, with twisting sepals, and flower colour ranges from
blue/purple to pink/hot pink to white. Seedheads are silvery and
long-lasting. All of the integrifolias are vigorous and easy growers,
tolerant of a wide range of soils and exposures, though of course they
will flower best in a rich, deep soil and sunny site. They are excellent
additions to the perennial or mixed border—one of mine grows through a
which supports it as it grows, another is in the perennial border
supported by some Artemisias, and so on. They flower right through the
summer, too. For the space invested, the returns are great, and you owe
it to yourself to try them. Believe me, you won’t regret it.
THE TANGUTICA GROUP
This is another fascinating group of clematis which make excellent
additions to the garden, and includes orientalis, serratifolia,
ladakhiana, etc. Foliage is universally excellent in texture,
finely-cut, and clean. The seedheads are outstanding and long-lasting.
Plants are vigorous and extremely free-flowering, and are tolerant of a
wide range of situations. Drainage must be sharp, particularly in
winter. Unlike most clematis, these have fine, fibrous root systems, and
resent disturbance—therefore DO NOT tease them out when planting, and
avoid transplanting if possible. (If you must transplant, digging a huge
root-ball will greatly enhance your success.) The one caveat that
applies to young plants in this group is that they will NOT tolerate
drying out, so we recommend the use of water-absorbing polymers
(Soil-Moist, Terrasorb) at planting time. Once plants are established
they are better able to withstand drought. Pruning can be B or C, or a
combination of both to give early and later flowers. Mature plants are
unbelievably prolific and make a spectacular display against a dark
evergreen backdrop, such as yews or junipers.
THE TEXENSIS GROUP
Clematis in this group all have our native C. texensis in their
backgrounds, and are colourful and easy growers. They are excellent in
that they start flowering in mid-summer when not too much else is in
bloom, and they are prolific and vigorous. Flowers
are campanulate, opening more or less widely, and colours range from red
to hot pink
and varying shades and combinations of pink. They are extremely heat
tolerant, a most
important factor, and they don’t wimp out when the temperatures exceed
This group of clematis has really come into its own in the last few
years, and small wonder. They are all vigorous, vining, and floriferous;
their foliage is neat and clean,
and for the most part they begin their flowering season just as the
spring flush has ended.
While their flowers may not be quite as large as those of the
large-flowered hybrids, they more than make up for this by flowering
long and profusely. There are lots of colours to choose from, too,
purples, blues, reds, pinks and whites, with even a couple of doubles
and bi-colours! Best of all, the dreaded clematis wilt rarely rears its
ugly head in this group. They’re great to grow on trellises, shrubs,
trees or any application you can think of. Pruning is easy, too, a quick
chop to the ground (6”) is all it takes.
OTHER SMALL FLOWERING VARIETIES
Although the flowers may be smaller, these clematis can make just as
much of an impact
in the garden as their larger-flowered counterparts, thanks to the sheer
number of flowers produced. They’re also robust growers and excellent
plants to consider if you’ve had
problems growing the hybrids.
LARGE FLOWERED HYBRID CLEMATIS
DOUBLES AND SEMI-DOUBLES
The bi-colours represent quite a diverse group amongst the
large-flowered hybrids, not only with regard to colour but flower form,
floriferousness and overall vigour. We have endeavored to put together
a selection of varieties that for us have proven to be the strongest
growers and most profuse bloomers. Some are flamboyant, others more
but all will benefit if planted in locations where they will be
sheltered from the hottest sun,
this will not only help retain flower colour but will help the
individual flowers last longer.
Eastern exposures are always preferred for this group.