I have Clematis jackmanii, growing up trellises on the same sort of exposure on the front of my house. Not much for scent, but they're spectacular.

I agree that the jackmanii looks stunning. Is it more durable than other clems? I had a Rebecca clem at my last house and the wind often tore off the flower petals. It was a young plant though.

I have several more of the jackmanii vines in different locations/exposures that get wind and afternoon sun, and I've seen them suddenly lose all their flowers. But my impression is that its more a question of keeping the roots moist so they can deal with the drying atmospheric conditions. But there is no scientific evidence.

I've planted maybe 10 different varieties of clematis over the years, trying to mix colors and all that, and the jackmanii is so far superior, dominating the others, that it looks like I'm some purple flower freak.

I really want to get out there and beat the tar out of the Porch Jackmanii!

I know that I've talked about this before but it really holds on to its leaves - thru the winter, and today! It can't be a healthy situation for the plant to have dead leaves under the new growth!

Kvenkat, this is a windy location but you may benefit from a few more mph's and be able to grow one without this concern.

The Porch Jackmanii was pruned a couple of years and recovers well enuf to have decent blooms but it seems a little un-natural to me to take off plant parts that will bloom, since it blooms on last year's growth.

I am wondering about just going over the plant sometime during winter and beating the tar out of it with a broom! Would that dislodge the dead leaves and be proper horticultural technique?

The jackmanii on the garage has just a bit more shade and is much more restrained in its growth. Dead leaves just don't hang around all winter.

Steve

Steve, jackmanii is a type 3 clematis, which means that it should be theoretically whacked down to the ground every early spring, and then they grow so fast that they'll bloom on the new growth. This works. But some years, I just don't get around to remembering to whack the things off in early March. So when I look in April or something, there under the dead leaves is a foot of new growth coming out all over the place. So I just leave it, and after a while, it covers up the dead stuff.

A couple of my vines are true monsters, 1 foot dia with 50+ stems coming up from the ground, and if I don't whack them back I end up with something about 3 foot thick x 5 foot wide growing up the wall. And I've never tried leaving it unpruned for three years in a row, it might swallow the entire house.

I once gave a gift jackmanii to a neighbor, who has it growing up some ancient pear tree in her front yard. She has never pruned the thing in maybe 10 years, and it still blooms and looks wonderful.

And I'm not convinced that pruning it to the ground means more new shoots from the ground, I get those anyway.

Anyway, I too use a broom to knock the dead leaves off, just whacking it gently gets most of it, not so much brushing it, that just snaps off the new stuff.