I‘m in Minnesota 4B and have several Mock Orange. Mine have bloomed reliably, but the issue I have is they are not particularly attractive the rest of the time. i believe you need to use caution pruning them after mid summer or you will lose blooms for next year. Maybe in different parts of the country people have a different experience with them. Honestly, if I had experience with them earlier, I would have switched them out of my landscape plan when I built.

My impressions from all my readings is not that they are hesitant bloomers but that they often lack the scent they are known for. My experience is that they bloom heavily and from an early age but some species or cultivars have a much stronger and more noticeable fragrance than others.

Lack of flowering is usually attributed to improper timing if any pruning. That should be done immediately after flowering is completed.

It is a rather ungainly looking shrub so does require some careful siting in the landscape to be fully appreciated. The native species, Philadelphus lewisii, has a much more appealing mounding and compact habit, is a very heavy bloomer and has what is considered one of the strongest and best scents for a mock orange.

I bought one years ago after a few years of reading rave reviews. In the oh, maybe 15 years I've had it, I think it's bloomed twice, maybe three times, and within the last few years. Every year I say I'm going to remove it but I never do. Partly because it does give some privacy at about 10 feet tall.

The funny thing is one year about four years ago I did indeed go out with the intention of cutting it down, but it was in bloom! I didn't notice any spectacular fragrance though. I don't really recall any fragrance at all.

About two years after that I was out in the garden in that area, and I suddenly smelled this marvelous scent. I immediately thought it must be the mock orange (which had indeed had some inconsistent and unfragrant blooms since that one time) but I literally stuck my nose in the blooms and that was not where the scent was from. I was extremely stumped as to where and what smelled so wonderful. Still don't know.

I've pruned it some in the last two years with the intention of finally replacing it. Sparse blooms, no fragrance. Sorry I can't remember the cultivar but as I mentioned I got it at least 15 years ago, so not a newer one.

One last thing. The summer before last, I was walking down my street, a street I've walked down for 25 years, and was suddenly stopped in my tracks but a wonderful scent. I looked to the side of the road and sure enough, I recognized the form of a mock orange. And I stuck my nose in its deliciously fragrant blooms. So THAT'S what it's supposed to smell like I thought! It was then I decided to remove mine and possibly try another variety. I cut it down by half that year, and may finally take it out this year. Again, the only reason I haven't yet is because of the privacy factor. As soon as I decide what to replace it with and save the funds, that thing is outta here lol!

:)

Dee

I think we need to establish where the OP is and what shrub they are asking about. Is this Philadelphus? Choisya? Murraya? All can have the same common name.

Philadelphus is very, very easy from cuttings so if you know someone with a good one beg a few twigs.

I have had experience with Philadelphus. I had an old shrub that was probably installed in the 1960s. It was in a line of shrubs along the lot line that got a decent amount of sun and it would bloom with fragrance. Then the trees grew taller and as it was in more and more shade, it bloomed less and became lanky and unsightly. I did remove it as we were renovating the whole garden and I didn't replace it. So, I can't help but think it might perform differently in more sun. If you feel up to it, you could move it and give it a chance in a new location.

I then bought a Philadelphus 'Buckley's Quill' from a local nursery. It was a small size and is supposed to top out around 6ft and has small double flowers that look like stars. I put it in a foundation bed at the back of the house under a window. The first 3 years, I didn't notice any fragrance even when it bloomed. Then the last two years, wow, is it fragrant! But last year, I had some issue with discoloration and dropping of the foliage which I have no idea what it was from. This spring I pruned it back by at least a third if not a half and added some compost around the base and I will see how it does. Right now it has leaf buds coming out all over it, so I'm happy to see that. Not sure it will bloom this year with such a hard pruning, but I'm hoping it will at least be healthy and that it was just missing something that the compost might add.

Now this is one of my favorite fragrant shrubs in the garden and I will either buy another one, or I'll try another Philadelphus variety. Definitely worth it.

if you want info on how plants might bloom where ever you may be.. it might be wise.. to tell where you might be.. big city name .. right flora....

if you are talking about philadelphius.. i had 8 to 10 of them.. in my ground freeze MI .. and i dont recall bloom failure ever being a thing .... if winter was so bad.. other things didnt bloom on schedule.. i wasnt going to say it was phila's fault it didnt either ...

that said.. there are the very old carp plants that barely smell and have small flowers... and there are some newer hybrids.. or cultivars.. that have 2 inch flowers covering a 5 by 8 foot plant.. that you can smell from 100 feet away. if you happen to be downwind...

GET ONE OF THE GOOD ONES ...

ken

Philadelphus lewisii 'Snow Velvet'

I was just uploading some photos for another thread and came across some of my mock orange, which I forgot I had taken. No further help really, I guess, but you can get a small feel for the level of bloom. This is a well-established, 15-year-old shrub of well over 10 feet tall, at least five feet wide, and here was one of the few sparse sections of bloom (with no fragrance)

:)

Dee

P.S. PM2, I always have you in mind when I stand looking at my shrub, pondering and debating lol. I always remember your shrub and your comments on it and that's when I think of replacing mine!

Maybe the OP will return and tell us their location and which shrub they are talking about.