IMO Tangutica is a very, very, very, aggressive Clematis. Mine almost did in a part of my very vigorous Wisteria. On the other hand I've cut it to the ground, (two truckloads to the dump) and now letting it have it's way with a length of fence. It will be cut to the ground again next year. There is another yellow Clemie on the market introduced into the trade by the U.B.C. botanical Garden, Clematis chiisanesis Lemon Bells, a strong grower but not overly aggressive. It might be an alternative choice to consider.

A......

Here is a link that might be useful: Lemon Bells

Thanks. I just planted it with my sweet autumn clematis, which grows up a 6' obelisk and then through the security bars on my front door gate & transom (I do, after all, live in the city). In late summer, my house looks abandoned/haunted. I like to think that it looks like a crazy cat lady lives here (she does).

Let them duke it out. We'll see what happens.

Ditto to the vigorousness of tangutica. Was so vigorous that I removed both it and Helios from my garden. Way too much seeding and suckering on both.

I can tell you what happens when you put your tangutica and sweet autumn together from personal experience....your sweet autumn dies.
Karen

thank you, Karen. that's an eye-opener for me- I had considered Tangutica myself (and I had already ruled out SAC because of its aggressive reputation). Brandy

I may be in trouble..I just got a Tangutica 'Golden Harvest' you say, it is more of a thug, than SAC?

I just talked to a local arboretum curator, who says that in his experience, while tangutica is vigorous, it is not overly agressive or invasive. He thought that placing the tangutica with my SAC could work out well.

Of course, everyone's experience is different, as are everyone's growing conditions. Enough people on this board had a problem with tangutica that it pays to be very cautious.

I have a tangutica called Sherifii which I bought locally about 5 years ago. I have mentioned this variety on here before and noone recognized it. While it is a vigorous clematis it is nowhere as quick a grower as my two SACs. The vine itself is less thick and more delicate, but with lots of flowers & very silky pretty seedheads.

I do, however, grow it in a poor soil location. My normal soil is heavy very fertile clay, but this area is fill dirt with some clay & is heavily thinned with gravel for plants that like it dry such as lavenders, penstemons & various rock plants. No amendments of humus and manure are ever made to this soil. Under these conditions it is a vigorous but quite manageable clematis in zone 5 with its short seasons. I have had only one seedling and that may have been a rooted stem away from the mother area.

The yellow flowered tangutica makes a very pretty backdrop for the mostly mostly purple & rose-pink plants in this bed. I keep it on a 3 ft high but wide trellis structure & let it puddle on the ground about 4 ft wide and much longer.

Any parts of the plant that go where I don't want them can easily be cut off with small hand sheers. It also does not seem to make the woody base that I have on the SACs. In my situation the two plants are not even comparable, with the SACs being much more aggressive.

My tangutica is dueling with my coral honeysuckle. They seem to co-exist ok the past few years. Vigorous is how I'd describe the tangutica. Loads of bloom and fuzzy heads after, but not as thick as my SAC and not as tall, certainly not as aggressive. And the tangutica gets more sun -- the SAC is clear across the yard in more of a dappled sun. I'm in zone 5b-6a with clay soil. My sister lives a mile north and her tangutica (bought at the same time) is a wimp that barely reaches 3.5' tall and hasn't spread one bit. She gets a mere handful of blooms.