Try posting in the rose forum -- people there should be able to help. There's also a rose gallery (link on rose forum page) -- if you can get a photo and post it, that would be even better.

Or if you can catch people out in their yard (or are comfortable knocking on doors), go ahead and ask. Most people are happy to share gardening info.

Good luck!

Here is a link that might be useful: Rose Forum

There are four different types of roses that have "Knock out" in their names.
Original "Knock Out" is very bright/ neon/ pink. It is one of the most repeating bloomers in my garden. Flowers are single, in cluster 5 or more. In my opinion they look the best from distance in-group plantings. Foliage is dark green and glossy, young leaves have burgundy color.
Another is "Pink Knock Out" have similar growing and blooming characteristics as original "KO". Bloom color is light pink / rosy-pink/. They look the best in mass plantings, from distance can be mistaken for Rhododendrons.
And the third variety is "Blushing knock Out". It seems grows smaller the fist two and definitely need some afternoon shade. It's pale pink flowers fade to dirty white in matter of hours. I planted mine at the base of original "Knock Outs" in semi-shade. They look very nice together. Foliage on this rose is lighter green and blooms remind me of "Dogwood"
There is another rose called "Double Knock Out" I have not seen it personally yet, but hopping to get one up coming spring.
All of these roses are virtually carefree, once a week watering and twice a season fertilizer will keep them looking nice from mid May until late October
Tatiana.

Tatiana--thanks for all the info! I wonder, when you say group plantings, how many plants do you have in a group? I am hoping to plant in a strip along the front of my yard but I don't want it to look sparse. The strip is about 12 feet long and 2-1/2 feet wide. I can check the recommended spread but I wondered what your own preference is.

The bulb catalogs are starting to come in the mail! I wish I had room to plant some when the time comes but I think things are pretty full for now. It's just fun to daydream.

In my border "Knock Outs" on the back for screening purpose with about 5-6 ft distance. They are 3 years old, every year I cut them back to 2-3 ft high to the ground, they reach 6x6 by the end of summer. In front of the border I planted "Blushing Knock Out"s, mixed with perennial such as salvia, daylilies, irises, lavender + some low growing annuals in white, yellow and blue tones.
This border is about 45 foot long by 8-12 ft wide runs along my driveway. I do not have water source near by, so the plants receive only occasional watering + rain. Despite that they thrive and bloom non-stop.
As it seems you have limited space I would just mix "Pink Knock Out"s and "Knock Out"s , as they have similar size and form, in one row + plant some lower growing perennials and annuals in front of the row.
You can add "Happy Returns" lilies , they look good together. If you plan roses 3-4 ft apart they will form solid hedge probably in 4-5 years. In you zone you should not have much of winter kill. I am about 200 miles south of you, my "KO" do not suffer from winter at all.
I also would advise you reasonably priced, quality sours for "Knock Outs" mail Order nursery from Texas "Chamblee's Roses" . They are absolutely wonderful, knowledgeable people. Their roses are under 10 dollars and they charge actual shipping. Over 60% Roses in my garden came from them, all of them doing great; e-mail me if you have more questions about roses.
My e-mail is northjackson@consolidated.net

Here is a link that might be useful: chamblee's

Amity Rose & Garden Nursery has the original cherry pink Knock Outs on sale this week for $9 each + actual s&h

Here is a link that might be useful: Amity Rose & Garden Nursery