I have Miss Kim Korean lilac which is categorized as reblooming. (I suspect ”boomerang” is just branding.) It has one main bloom in late April and, if assiduously deadheaded/pruned, another much smaller bloom in June (ish?). It certainly does not bloom continuously nor does it bloom into fall. I’m in zone 6a and it performs well and its fuller and compact-ish habit make for a better landscape plant than traditional lilacs which tend to be sparse and leggy/scraggly, but the flowers are much smaller and less perfumed. So I’m overall iffy on them.

If I were you I’d look at panicle hydrangea. There are some dwarf varieties but even the larger varieties can be kept fairly compact with aggressive pruning. They don’t bloom in Spring, but will take you from midsummer through fall. They love full sun and tolerate heat and some dryness much better than the traditional mophead hydrangea.

I had 2 allegedly reblooming lilacs in my Mich....if spring bloom was a 100... rebloom was a sporadic 10 or 20...

I was not impressed by marketing mumbo jumbo

Ken

yeah i have heard that, thnx

I had a “bloomerang” lilac, an alleged rebloomer. It did not perform to expectations; it had a nice flush in spring, and then only a sporadic bloom here and there for the rest of the season.

To be fair, I only had it in my garden for three years before giving it the heave-ho, so maybe it would have performed better eventually.

A spirea shrub might suit your needs. I have Double Play Doozie and it requires almost no care. It just needs ample sunshine and it’ll bloom all summer. (Photo from internet)

Very few shrubs will offer continuous flowering all summer and into fall.......ken's unicorn!! 🤣 The dwarf panicle hydrangeas are a possibility if you don't mind flowering that starts later in the season. Otherwise, something like a landscape rose - Knockouts or OSO Easy or Drift may be more what you are looking for.

My experience with the reblooming lilacs (ditto reblooming azaleas) is the same as others have reported. A nice early season show, then just a few flowers randomly now and again.

How about a shrub or perennial that has color in the leaves to give you more seasons of interest after it flowers. I just planted a My monet purple effect weigela, it has a mint green and white varigated leaves that takes on a purple tone especially in full sun. gets about 2'5 x 2'5. I really like the texture it has brought to that corner of my garden it really stands out amongst all the greens.

this bed is newly planted this spring so everything still needs to fill in but you can see how the leaf colors of the weigela stand out