PLANT OF THE WEEK #18: Clematis napaulensis

For years I’ve complained that June is by far the most boring month in my garden, and that nothing – absolutely nothing – actually looks like it’s enjoying June by starting to flower in this bleak month.  The best I could hope for is a waterlogged nerine or a late salvia bloom, cryogenically preserved by brutal frost.

Then this year one plant – Clematis napaulensis – proved me profoundly wrong.  Not only did I discover that it starts to bloom in June, but that it does so on a plant so richly clothed in young vigorous growth that it has all the appearance of mid spring.  I planted my two plants about five years ago into such appalling, unwatered and unassisted conditions that, while they grew well from day 1, it’s taken them a while to really build up the bulk to establish when their preferred flowering time might be. 

The flowers are more curious and compelling than they are showy. Greeny-cream buds appear in late autumn, and swell, in a cluster, almost grape-like, until the first of them splits open into four slightly peeling back segments, to reveal a protruding brush of remarkably plum-purple stamens – a colour that takes you by surprise, as there’s no hint in any other part of the plant that it’s capable of conjuring up this pigment.

A facebook follower recently commented that they reminded her of fuchsias.  I hadn’t seen the likeness myself, but now that it has been suggested, I get it.  The ‘petals’ have that slight balloon-like quality, along with a hint of ribbing, and touch of translucence, of fuchsia buds that we 60’s kids remember popping when we were little. 

Flowers are followed by wonderfully fluffy seed heads, ornamental in their own right.

Flowering is largely on ‘wood’ from previous years growth, so like other clematis that flower on older growth (such as C. montana), you must leave them unpruned in order to maximise flowering.  If they get too big or unruly, you can hack into them – right back to stumps if necessary – though in doing so you’ll sacrifice a year or two of flowers.

The most notable aspect of the life-cycle of Clematis napaulensis is that it’s summer deciduous.  This is always a little alarming, as it doesn’t lose its leaves like a winter-deciduous plant might, with colouring followed by a clean drop.  It just kind of looks like its shrivelling up as the weather warms.  Then it’s dormant – quite conspicuously so – through the summer, but breaks into leaf in late summer, even as the heat is at its greatest.  You’d think it’d really capitalise on its chosen strategy and snooze until the weather cooled down.  It may be that during this last summer it came into leaf earlier than usual, given all the wonderful late-summer rain we had, and I can’t say I’ve taken enough note of its leaf-up date in other years.  But it was Feb this year, and the rainfall may also explain why it seems to be a bumper year for blooms.

This life-cycle anomaly makes this plant a bit tricky to place.  I have it on a very prominent trellis, and have no trouble ignoring it for the summer.  But a better strategy would be to grow it over a winter-deciduous shrub of approximately equal vigour.  The vigour match is important, as the shoulder seasons could see the clematis outcompete the shrub.  If you’ve nailed the perfect companion/host, or have any suggestions for some, leave a comment below!

Also, if anyone can explain why a plant from Nepal (as well as China) should contain within its specific epithet the curious spelling ‘napaulensis’, we’d love to know that to!