I have no experience with the quick fire and little experience with little-limes. I just planted 8 little limes and they are very nice except the fact that they are stressed and have either lost some foliage or are weeping but that should clear up next year. The little limes should stay compact and tight in the right growing conditions (6+ hours of sun and moist soils) they should get about 4-5 feet tall and wide but I plan on pruning my back to stay about 3'x'3. I little limes look the best of the small tight shrubs. Limelights are the same just bigger and stemmy-er. Little Lambs look really nice too, very similar concept to little limes except the blooms are white. The limes blooms are the nicest I have seen in a compact, the lime green color is very cool but over exposure to sun will cause them to turn white and subsequently pink faster. These are very hardy shrubs and should grow fine in my zone 6a, not sure about your zone 4. Check Proven Winners website for more info.

You can Google image search for various states of bloom. All hydrangea paniculata begin mostly white and fade to pinks and browns.

Both are "dwarf" hydrangea paniculata, as they aren't supposed to exceed 5' in diameter. There would be zero dieback down to zone 3. All paniculata are drought tolerant and require full sun in zone 4. 'Long as the soil stays moist and mostly shaded, little manual watering would be needed.

Little Quick Fire just came out this year, so not many people have it. It would be a wise choice for mixed borders as full size QF (like mine) can exceed 7' in diameter. QF (a rare case) should NOT be pruned past early fall (when the leaves turn), and never after the plant begins to leaf out in spring - otherwise you will eliminate blooms before they happen.

Little Lime is a top-rated shrub. Each spring, simply prune out tiny outer branches and leave the thickest toward the middle. There are no pruning restrictions on Limelight.

QF stems are ruddy in color and have dark, rough, medium sized leaves. Limelights have much lighter stems and leaves (light green across the board).

Thanks to all who responded to my post regarding "Little Quick Fire" and "Little Lime" hydrangeas. Very helpful!

I have no experience with little quickfire, but I did recently plant a little lime in a half barrel container... gets about 4-5 hours of sun and seems to be doing okay. Similar to sampson's, mine is slightly transplant stressed and has been losing its inner leaves a bit. It's blooming beautifully though and the flowers are still green (I see a bit of pink creeping in on the edges). It rained recently and a couple of the larger clusters fell over, but I lightly shook the water off and they're popping back up as they dry out.

I'm really enjoying the LL so far!

Does anyone know which has a longer bloom time - Little Lime or Quick Fire?

The blooms stay "on" and last thru winter so whichever blooms first would have blooms that last longer. In the earliest department, Quickfire is probably the earliest or one of the earliest. In Zone 6 for example, it can bloom in June.

My QF started blooming in mid June and Vanilla Strawberry Sundae and Vanilla Strwberry in mid July. My guess for Little Lime would bloom around the same time as my VS.

LL bloomed quite early for me two years ago. Had no blooms in May but it had started the broccoli phase in May and managed to get a handful of blooms open. Of course, it was quite a warm winter that year and you will not see that happen in Zone 4/NY. I did not pay attention to this year but it may have been blooming by mid June or so. Again, not likely to happen this early for you in Zone 4/NY.

Limelight and Little Lime are the last to bloom of the H. paniculata in my zone. I don't think it was until mid August that they had fully bloomed. There is an advantage to this as you get the white vs most others are pink.