How long have they been in the ground? When they were planted, were they left in their burlap bag? Lack of blooms and intermittent blooms probably means not enough moisture during summer, lack of nutrient-rich soil or buds that are getting frozen back.
I've been disappointed with the flower displays of the kousas around here.
I've seen spectacular blooms on Long Island, prompting me to plant several here.
Our cornus floridas bloom great, but kousas sparingly.
Pictured is bloom from cornus kousa Satomi from this year.
To get 3 blooms in a picture was remarkable enough to take a picture,
which tells you how sparsely it blooms!
I've speculated they need more sun than c. florida to bloom well (mine are understory),
but it's just speculation. Maybe the wide temperature fluctuations/late frosts, etc also contribute.
Where I am isn't exactly a sunny place yet they bloom heavily each year. They're loaded with blooms right now and it's been a mostly overcast spring. Maybe having that moderated climate does make a difference so planting amongst other plants (protected) instead as solitary might make the difference.
Wee, I'm thinking it's the humidity level in our area. Mine never blooms like the one's I see in other pictures. Mine gets sun for about 8 hours a day but still blooms sporadically. It is still a beautiful tree with great structure, gets a lot of attention from visitors so I think I'll keep it!
Can't get much more humid than around here. It's been raining for weeks and these trees are right on the ocean's edge and yet still bloom heavy. Maybe it gets too hot in the summer and they prefer the cooler summers or somethin'.
Boy, those Satomi's are beautiful.
Exactly why I planted mine, but sadly I don't have much to show for it.
Mine is 15yr old already, so I presume it's doing as much as it's ever going to do.
I'm going to blame it on high night-time temps.
Certainly couldn't be my gardening skills...
Thanks, Growin. This tree was grown from a 15" seedling bought from our county conservation program. It first flowered three years ago, skipped a year and flowered last year.I think last summer was drier than normal. This spring, however, has been comparatively wet. I've used some fertilizer,too. I'm crossing my fingers.
I don't know where North Chelmsford is in the grand scheme of Massachusetts, but I bet you don't have dramatically different growing conditions than the august institution of Jamaica Plain - the Arnold Arboretum. They have some spiffy specimens, indeed. You might find images on their website.
Slightly more conducive to growing Kousa Dogwood (except for the occasional gale) is Martha's Vineyard, home to the Polly Hill Arboretum. Among the many products of her prowess were several named selections of Cornus kousa. You could check their website, or here in PlantFiles.
I think the ingredient in deficit here is patience. From seedlings great trees grow...just not instantly.
But there are good ones out there - even this one locally in KY.
Wow, now there's a nice specimen and I like where it's planted. Real good bloom-set. Yes, patience is needed for Kousa. My boss just mentioned yesterday, when I requested some Satomis to sell, is that people don't want to buy them as the blooms on a young tree look washed-out or pale in comparison to older specimens in the landscape. I also mentioned to my boss that trying to sell florida rubra around here isn't as easy as a good Satomi. He sent me Styrax instead. I await my Satomis patiently.
The plant illustrated is Cornus angustata Empress of China™ (selected and patented by John Elsley), not Cornus kousa.
The point I'm trying to make is that Kousa Dogwood (like many flowering plants) has genetics across a wide spectrum when grown from seedlings. One should not expect a random seedling to behave like a well-known named selection - especially if that selection was made because of heavy flowering from a young age. That is NOT a trait of run of the mill Kousa Dogwood. A plant like Cornus kousa var. chinensis 'Milky Way' does have this trait, and should be expected to be covered in flowers even on a young budded plant.
Certainly climate and soils play a role. If Kousa Dogwood is spectacular on its home turf of Japan, then similar growing conditions (see: Vancouver, Seattle, Portland) could be expected to yield similar results. The rest of us get to slug it out, and learn by trial and error.
Maybe we just need a slight tremor every now and then. In which case, tag Weerobin - you're it (New Madrid).