I have a huge planting of 5-6 pink oleanders against my garage with a ring of azaleas in front that I keep about 2.5 feet tall. I have always hated the oleanders because they grow so fast. I've always wanted to get rid of them but have no idea what I would put in the space they would leave. My mother has knockouts that have gotten taller than I thought they typically did. They are easily at least 4.5 feet high. Does anyone think those might be an acceptable replacement?

What direction does the wall face?

Knock Out roses can get very large: tall and wide. But they can be pruned to about any size you want to keep them at with regular pruning. I am not a big fan of the single ones but I do enjoy my Double Knock Outs at this time of year, the dark foliage and the bright blooms really brighten up the garden. I used to have a row of Oleander bushes (I had always wanted some), but they did not get enough sun to bloom very well, and they did constantly seem to be much taller than I wanted to keep them. The Knock Outs do grow fast also, but I have never let them get nearly as large as the Oleander bushes, even if not pruned I am not sure they would ever get that large.

@Steve812
The wall faces southeast. It gets a great deal of full sun. There is a small oak tree about 15-20 feet away.

@Seedfork
Yes, I think I would get double knockouts. As I mentioned in another post, I'm really lacking blooms this time of year. The oleanders don't bloom until the summer heat really sets in. They are great but they grow so fast and I'm always paranoid about the toxic sap. I used to have some white ones behind the waterfall of my swimming pool but I replaced them with Mexican fan palms b/c I was paranoid about my then toddler son putting the leaves in his mouth. Now 6 years later, those stupid palms are so ridiculously tall that they are growing into my oak trees. I let my landscaper pick them out. Another reason I don't use him anymore...

I think a SE facing wall should be about perfect.

My own Double Knockout is growing a little more slowly than I expected, but it is only entering its second season. When I grew Knockout long ago in NJ I found the plant grew quickly to six feet in two years. Growing in half shade it topped out at about six feet in two years. There was a subtle fragrance to the flowers that I enjoyed. And it looked good planted in front of a young magnolia.

I'm sure Larry's experience on size of the plant is more representative of what you can expect.