Not sure what you consider small for the space but this is good advice listed below. More of my experience first though. Ninebark does set buds on old wood. So ever few years or so when you need to cut it far back you will lose buds for that year. Otherwise cutting it back a 1/3 after it flowers is just right. I actually planted a Diablo hedge and wanted the large size and it just wasn't get there, it was very leggy. Cutting it back got the desired results. Ater that I only use ninebark sparingly in moist sites with good air circulation. In humid and dry sites they are EXTREMELY susepctible to powdery mildew. I learned that the hard way after I was told ninebark was drought tolerate. Sure it is, but if its humid out, look out PM! Coppertina by far has superior color to all others. Its the only one that should be used in my opinion. What I love best about ninebark is the way it tolerates different pruning methods. When left alone for years to grow into a medium to large shrub, the only care it needs is to remove dead wood, or to thin out a quarter of the stems each year in the winter or spring, right down to the base, to maintain a bushy habit. This rejuvenates the plant, helping to prevent a leggy appearance, and encourages the production of flowers and fruit. Ninebark also responds well to being clipped back by half every few years in order to keep it in check, particularly if used in a foundation planting. This should be done right after flowering, so the shrub has time to form new buds for the following season. The easiest pruning method of all, however, is to cut ninebark back to a height of 15 to 20 centimetres in the spring before it leafs out. This technique is known as coppicing, and results in a flush of new growth with particularly large and lush foliage�absolutely stunning in the coloured-leaf forms�though it comes at the expense of both blooms and seedheads. The lush growth and more compact size resulting from hard pruning makes ninebark especially wonderful in a perennial border, placed in the middle to back. Plants should be allowed to establish for two to three years before using this method, however, and it should be done only every other year since it temporarily weakens them.

This may not be helpful, as they are perennials and not shrubs, but I keep thinking of how beautiful anemones would look on either side of a gate. They're tall when they bloom and perhaps something else could take over when they're not blooming? Or do an asymmetric arrangement with two tall perennials (blooming at different times)? Or one perennial with one grass, as christie suggests? Or something that climbs one of those pretty pyramidal supports? Just wistful thinking on my part, perhaps. So tough to find something that narrow. I sympathize about loving the ninebark. I'm battling the urge, right now, against getting something that I don't think I have the spot for - so you are not alone! Good luck!

george, cutting from the outgrowth? or tip cutting of the branch? why? what do you mean "behave"? kt, the leaf color is better on the outer leaves that get more sun. can't find much about Diablo and Nana without stumbling on Summer Wine. The reference above from Fine Gardening is the only clue that this is not uncommon for the genus. http://www.taunton.com/finegardening/plantguide/genus/physocarpus.aspx? I did find out that "witches broom" is a fungal disease. I can't figure out if its fatal or not. I only got this plant this spring. I am going to bring this pic to the garden center and see if any other customers had same problem. Now... if only I could remember where I got it... :(

sorry if this photo is quite large... i snapped a shot of what our 'coppertina' looks like in an area where it only gets 1-2 hours of sun per day. the new growth is lime green with copper tips, it slowly fades from lime green into copper over a few weeks' period (see tips of leaves in center), and the stems remain bronze year round. you'd almost not know it, but the darker green ninebark behind it is 'summer wine'. they were really distinctly colored all of last year at this location, so i'm curious if the colors will darken/become more distinctive over time in non-sunny habitats. i'm going to stress both plants over the course of the next month or two to see if any color variance occurs as well.