I would go with two of the Adirondacks flanking a single Prairifire, Uneven numbers are best and 5 sounds like you are trying to squeeze in too many......you don't want to crowd things :-) And I like the contrast in forms between the narrow and upright and the more rounded and spreading.

Prairifire has redder leaves than the dullish color of Purple Prince. And increased disease resistance, which is very important with crabs.

Check disease resistance of each kind in your region. Hopefully the City is offering only known good local performers but they may not be. If any one of them is a martyr to mildew, rust or scab where you are they are likely to be homely during the summer season, year after year.

Thanks, both. The city provided these options as disease-resistant for our area. We have over 100 feet to work with and thought to plan at least 15' apart. We appreciate the insights. We don't want homely!

We welcome other thoughts, too! One other thought we had was to do a mix of Prairiefire and Purple Prince but wasn't sure how that might look.

Agree with @gardengal48 (PNW Z8/9) regarding odd numbers and that shape contrast as well as color contrast could be nice. Here's a visual of two Prairiefire flanking one Adirondack, or two Adirondack flanking one Prairiefire.

I would probably go for five, though (three Prairiefire and two Adirondack, since I like primarily horizontals with vertical accents). Spread is 15-20' for Prairiefire, 6-10' for Adirondack (per gardenia.net), so, using the higher spread for each, that would total 80' of canopy. You have 100' of space, so I think five should work.

Those Prairie Fires are gorgeous. i don't think the Adirondacks add a thing in those visuals. I'd plant 5 of the Prairie Fire - it would be a spectacular display when blooming, vibrant fall color and very nice forms when not in bloom.

notl77, where are you located? In some areas, Prairiefire (also spelled Prairifire) and Purple Prince can be moderately susceptible to scab. Also, depending on the width of your "parkway" (tree lawn), they may grow too wide and need heavy pruning to maintain clearance from the sidewalk and street. A variety with an upright habit may be more appropriate.

@simplynatural: You have a gift I could only imagine with the photos and visuals you provide! By any chance could you quickly come up with an image of three Prairiefire staggered with two Purple Princes? (Prairie/Prince/Prairie/Prince/Prairie). This is the direction we're leaning toward. Thank you!

@simplynatural: We are more than a little grateful. This is SO helpful; thank you. In a world that seems devoid of kindness anymore, we appreciate yours.

It is hard to find images of what crabs look like when they're not flowering! So many images show the two weeks they're in bloom--and it's hard to see what they look like otherwise!

Your input is helpful as we inform our thinking.

We continue to welcome thoughts but others. Stay well, everyone!