Has it bloomed in previous years? How far apart are they (I'm wondering if there's a difference in the soil)? Are the roots of the one that's not blooming mulched or otherwise kept shaded (though you'd think if the soil was too warm the whole plant would be unhappy)? Hmmm... All I can think of is the soil there is different, either too rich so causing lots of green growth but no flowers, or not rich enough, but again you'd think the whole plant would be slow-growing if that was the case.

Clematis are heavy feeders, and like regular watering. Also, they prefer to have cool roots.
SO - I'd recommend fertilzing, mulching, and regular watering.

Below is a link on Clematis growing basics from American Clematis Society.

Here is a link that might be useful: Clematis culture good link

Wow!!!!

In John Howell's book on the viticellas, he states that the viticellas are not heavy feeders. I have over 150 clematis in my garden and one year as an experiment I did not feed any of mine and I could not tell a bit of difference in bloom production. A lot of that could of course depend on the natural fertility of your own soil.

On another point, the idea that clematis like cool soil is a fallacy even though you see it written all over the place. What they in fact like that happens to co-exist when the soil is cool is moisture so mulching with an organic mulch that will decompose over time and add tilth and moisture holding capacity to the soil is heavily desired. Having the plants get consistent moisture is also desirable. Those living in areas where there is ample moisture may allow some to grow clematis without having to add extra moisture but for those living in areas where moisture is sparse during the summer, like the southeast where we have been in drought for several years, moisture will have to be added or the plants will suffer.

On the clematis forum, we have had several people say that they have had Polish Spirit, which is normally a monster of a clematis that blooms profusely, which for several years has not flowered at all or very scantily. The plants have been given adequate moisture and fertilization (stay away from high nitrogen fertilizers since that encourages green vegetative growth over flowering) and they still don't flower. We still can't figure out why those plants haven't flowered and suggested that the nonflowering ones be replaced with new plants. Another point to consider is that since one of the plants has never bloomed, perhaps it is not Polish Spirit. I can't tell you how many mislabeled clematis I and other members on the clematis forum have purhcased over the years.

As to your one that does flower and only flowers at the top, Polish Spirit belongs in pruning group III which means it will only flower on new wood. That means that each winter or early spring, the plant should be cut back to within several inches of the ground. If this doesn't happen, the older vines near the ground will get woody, stop having foliage and the flowers will be produced only at the top of the vines where the new growth occurs.

I suggest you try fertilizing your nonflowering one with a tomato or rose fertilizer since they are naturally low in nitrogen and high in phosphorus which will help with root development and eventually flower production. Keep the plant well watered but don't keep it consistently moist or the crown can rot. Since I don't know whether this clematis has ever been pruned, you might also want to cut the foliage back by half. I have found that after quite a few of my clematis have finished with their initial bloom flush, that cutting back by half, keeping them fertilized, and watered over the summer months, that I will get just as big of a flush of blooms in late summer/early fall as I do earlier in the season when they initially bloom.

One other point to consider is to get a soil test in the area of the plant which does not bloom to determine if there is something missing in the soil that might be the issue.

Thanks for the detailed reply - appreciated.

I do prune them back to about 6-12" in the spring, as I mentioned, so that's not the problem. I don't remember if the plants were blooming when I bought them, but I bought them from the same nursery the same summer. I did buy another one about two weeks ago from this nursery, and it is not blooming. I haven't planted it yet, so if I don't see any buds on it within the next couple of weeks I'll exchange it for another (they have a very good return/exchange policy).

I'll put some Rose Tone on the non-blooming older one next week and see if that helps.

I really hate to dig it up and replace it, it is lush and a nice specimen in terms of foliage/wall coverage.

That's odd, though, why people are complaining the Polish Spirit aren't blooming.

mxk3,

My DM rooted a Clematis a few years ago and handed it over. I planted it and for three years it grew but no flowers. Then I read that sometimes you can jolt them with some Tomato food. I don't normally buy the stuff, but for this one I did and for the last three years it has done very well. The Tomato food was only applied once. It was IDed as Ville De Lyon.

I also have a Polish Spirit that is lush with leaves but does not have one flower/bud. Perhaps it is just a dud. Really hate to dig it up while it is still growing well...flowers or not. Will give it one more year.