There is no size where they stop growing. They just slow down as they get more mature. Probably all sizes you read are correct for the age and location. They get taller in shade. The consensus is that they get 6 ft. tall when 10 years old and are erect in habit and don't spread much. The ones under the windows may eventually have to be pruned to keep from blocking the windows. The others should be OK. When you have to start pruning, prune in the spring after they bloom. This keeps from pruning off the next years flower buds.

Enjoy!

Thanks for the info Rhodyman - much appreciated :)

The consensus that 'Fashion' azaleas don't spread much is incorrect. We garden in one of the warmer parts of Zone 7B (Upcountry South Carolina) and have grown 'Fashion' azaleas since the 1960's. It's true that, if unsheared, 'Fashion' azaleas will grow six feet or more in height. However, they will also spread widely. As they spread, 'Fashion' azaleas tip layer, creating new plants. The five 'Fashion' azaleas in your photograph will be O. K. for a number of years; but with the passage of time, they will become very crowded. You may want to replace them with some of the slower growing Kurumes, like 'Christmas Cheer' or 'Hino Crimson' or maybe even a planting of the diminutive Gumpo azaleas.

Except that azaleas (and other rhododendrons) like to grow as a close thicket anyway. All of one kind of plant put closer together than would be done in an - ugh - tombstone planting to form a single unit with a flowing shape is called a "drift". Shrubs can - and should be, anywhere except those comparatively few instances where geometrically symmetric formal planting is called for - be planted in drifts just the same as herbaceous perennials, bulbs and even annual flowers.

You don't absolutely ever have to move any, though azaleas move relatively easily, so at whatever point you decided on redoing your landscaping, you could easily move some later.

I planted three 'Fashion' azaleas "too close together" about 25 years ago. Within 5 years or so, they had grown together nicely and looked wonderful. They still do look wonderful. They're planted in a good bit of sun (not quite full sun), so they're not even close to 6' tall; they're probably not much more than about 4' tall, if that tall. I've never pruned them except when drought has forced some cutting of dead branches or when I've collected branches for vases of flowers. The Fashions have spread sideways a good bit over the years, and they've ended up looking like a tall, tightly woven leafy green carpet, except when in bloom. Then they're a beautiful salmon pink carpet with little green showing anywhere.

The Fashion azaleas are much more floriferous than many azaleas, including gumpos, and they bloom at a better time if you happen to have many other azaleas to try to coordinate bloom times with. Our Hino Crimsons and Christmas Cheers have probably been planted in too much shade, but they haven't bloomed nearly as well as the Fashions do, and they seem a little less drought tolerant. By far the least drought tolerant azaleas have been our gumpos. By far! I do love to have a means of extending the blooming season and they make wonderful edgers, but you need to give them a ton of water during hot weather with low rainfall in order to keep them happy. If you do go with gumpos anywhere in your yard, I'd suggest going with pink or multi-colored, not white. The pinks don't usually really cover themselves with blooms, no matter how much sun you plant them in... but the white ones don't bloom much at all, whatever you do with them. (At least that is the unfortunate situation here.) Another season-extender azalea is Wakiebisu, and it's a heavy bloomer, wherever you place it. It's a moderate-sized plant that needs a good bit of water too-just slightly more drought tolerant than gumpos. (But we have lost large numbers of both. Fashion, Appleblossom and Hinodigiri do the best, but no azalea is going to live through a drought without significant watering.)

With your Fashions planted that close to the house with perhaps some shading from the house, they might get noticeably taller than ours (that I'd call moderately slow growers). If so, then you might leave plants 1, 3, and 5 in place, and eventually put the other two somewhere else, picking up the interesting color to reflect it from another location or two in the yard.

If you end up doing anything like making a curved enlargement of the under-window planting space to move some plants out toward the front walkway, don't forget about the nice contrast a camellia's leaves can make with tiny-leaved azaleas. Some Shishigashiras would look wonderful there, bring some fall color to your front yard, and endure droughts relatively well (after the first year when it is getting established). They will take a lot of shade. PInk hyacinths would look nice nearby in the spring too, if there's enough sun out from your roofline by a few feet. You could even place a shade-tolerant climbing rose at the corner there, something like Renae or Cornelia.

Well, I hope you do enjoy your Fashion azaleas; we still like ours quite a lot. Just don't neglect the watering with any of your azaleas...

Best wishes,
Mary

Thank you Jay, bboy, and Mary for your thoughts and ideas! Sorry it has taken me a year to get back to this thread.