I've had Appalachian Spring, and it is fabulous. It blooms slightly earlier, has more of a reddish color, It isnt prone to anthracnose. But 1 thing that it dosent like is being starved of water. Its one of the trees I have to make sure is watered. And it also isnt the dogwood you would want to plant in full sun, it can be really prone to sun scald.

You might lose a Cornus florida in a bad Chicago winter and I'd stick with one with kousa in it.

tj

Cornus florida grows fine in my zone 5 - I've seen some around here that are taller than a 2 story house, with equivalent spread. They are native around here, coming up in protected, moist woodland areas and even under power lines - I've never seen dogwoods damaged around here in cold winters, even through ice storms and -17F.

I would definitely go with Cornus florida - Anthracnose isn't all that bad around here, and there is a lot of resistance beginning to crop up even within wild populations.

I don't know about aka's claim that they c. kousa and c. florida are not closely related since there are several hybrids of the two species.

Here is a link that might be useful: Like this one

FWIW,
In my part of the world (Northwestern Arkansas) C. florida dogwoods are everywhere the soil is suitable. Sun, part sun, heavy shade. Dogwood Anthracnose does not seem to be a serious problem for them either, and nobody is sure why. Was reading about it a couple years ago that Anthracnose had been discovered in Arkansas, but when they got to looking it turned out it had been here for many many years and it's presence was widespread. However, unlike in much of the northeast the native dogwood trees appeared to be coping resulting in a lack of detection for many years.Can't say if it's climate, genetics or what, but Anthracnose seems to be the most concern further east.

Arktrees

Thank you for the great information, guys! I am so excited to learn more about these trees and your experiences with them.

Tsugajunkie and akamainegrower, yes, the lack of information about people growing these plants in colder zones is what has concerned me from the beginning.

'Appalachian Spring' is rated though zone 5b on many sites, and Cornus x 'Venus' through zone 4, though I am not sure if any trials were done to actually determine that information.

My parents, who live across the lake in Michigan, but farther north and much farther inland (zone 5b), have a population of wild Cornus florida in their woods. My cousin, who lives just a few miles south from them, has a wild Cornus florida in his yard that is much taller than his two-story house and is full and spectacularly lush. I wonder if lack of hardiness in Cornus florida is because many of the named cultivars have been selected from more southern-adapted populations?

The area I have is located in mostly full sun and in very well-drained soil. (Gardenapprentice, your comments about 'Appalachian Spring' make me think it might not be ideal in my conditions.)

I live in the city and very close to the Lake Michigan shore, so my temperatures are more moderated due to both proximity to the lake and by the so-called urban heat island effect. It's been at least several years since I remember the temperature in my area dipping below 0F, though the duration of cold temperatures and overall length of winter is much more intense than a more southerly zone 6. Most official "Chicago" temperatures are recorded at O'Hare, which is much farther from the lake and is almost always colder in winter and warmer in summer by several degrees than where I live.

Oddly enough, I don't recall ever having seen Cornus florida planted in my area, in spite of it thriving across the lake. The soil around here is slightly alkaline, so maybe that could be the reason?

In my neighborhood, there are several large established specimens of Cornus kousa which seem healthy and hardy. Their foliage did burn and crisp last summer with the heat and drought, though, but many other plants suffered just as much or more than these dogwoods.

Cornus kousa does have a very different look from Cornus florida but, at least to me, it is still beautiful and elegant. I would prefer, however, a tree with more striking blooms. Although C. kousa never fails to flower around here, the blooms never seem to stand out much.

Akamainegrower, what summer blooming trees other than dogwoods would you recommend as being more reliable?

Any more thoughts based on this expanded information? You guys are great!

Thanks again,
Ispahan

Mature Kousa can be a spectacular fountain of arching branches absolutely plastered with flowers. The 2002 Hillier manual puts it this way:

Numerous flowers with conspicuous, white bracts are poised on slender, erect stalks, covering the spreading branches in June

The general structural pattern is one of bending out, rather than the cupping up of C. florida.

Originator claims Zone 4 for this Kousa.

Here is a link that might be useful: Cornus kousa chinensis âGalzamâ

This post was edited by bboy on Fri, Feb 22, 13 at 12:12

I believe all kousas have now been removed from the cornus classification, but the commercial labels remain.

There are all still in Cornus. Even if one were to promote the four subgenera to genera, C. kousa & florida would still be together. Split Cornus into five genera, and you finally separate them. Funny you'd be splitting hairs over the features of those two species...they are very similar even when you factor in the differences in the flower bracts (the white showy bits) and mature form. This IS the same genus that has Pagoda Dogwood, Red Osier Dogwood, Cornelian Cherry, and Bunchberry as species. Now those are different!

Cornus florida, in my experience, struggles outside of Z7 or the warmer parts of Z6. If they are not killed outright, they are weakened and rendered more vulnerable to the many ills cornus are prone to.

Seed source!! Grow a C. florida from seed native to Michigan or southwestern Ontario and you should have a zone 5a hardy Cornus florida.

I would not say the resemblance of kousas to native flowering dogwoods is at all superficial, especially when not in bloom. When in bloom they do tend to have larger flower bracts than the floridas but about the same size (or slightly larger) than the nuttalliis. Mature kousas are neither stiff nor ungainly but produce a wide and softly drooping crown, perhaps weighted down by the profusion of large blooms they tend to produce :-) IMO, Venus combines the best of both species - cold hardy, disease resistant and a very prolific flowerer with large, very showy bracts. The tree is quite stunning in flower, even when young. We sell quite a number of them as we do kousas but then floridas have too many issues here, as do our native nuttalliis.

FWIW, all the literature I've seen still includes kousas within the genus Cornus but under the subgenus Benthamidia. At best the terms are considered synonymous.

Synonyms of Cornus kousa are Benthamia japonica and Benthamidia japonica. C. florida has the synonym Benthamidia florida. Alternative names for C. alternifolia, C. sericea, and C. canadensis (respectively) are Swida alternifolia, Swida stolonifera and Chamaepericlymenum canadense.

The 2002 Hillier lists them all under Cornus, mentions that if you split them up then only C. mas, C. officinalis and C. chinensis remain in Cornus, with the others being spread around through Swida (Thelycrania), Chamaepericlymenum and Benthamidia (Benthamia, Cynoxylon, Dendrobenthamidia).

It boils down to the C. mas types being Cornus, the ones with the bractless flower heads being Swida, the creeping, not-truly-woody dogwood(s) being Chamaepericlymenum, and the ones with the showy bracts being Benthamidia.

So C. florida and C. kousa would still be in the same set. Unless you were to break Benthamidia down finer, as mentioned above.

Cornus kousa is much more tolerant of neutral to slightly alkaline (and dry) soils and more resistant to borers as "compared" to C. florida.

Personally I would never bother with C. florida unless a hybrid or I had more acidic soil and I wanted that earlier bloom.

Maackia amurensis is nice mid-summer blooming tree

I dunno but I just prefer c.florida. Mainly because I rather have horizontal branching versus something that looks like a bush. It's just me but, I don't like kousa for the fact that the leaves come out before the flowers. But to be honest dogwoods in general are nice but you must imitate their natural habitats in order to make them happy. I just hope you don't go crazy on us and plant a Bradford pear tree lol those trees are the biggest problem you'll have, cleaning up multiple fallen branches and the messy fruit and stinky flowers.

Hmmm... Other flowering trees - How about the all-around fallback amelanchier? They look nice, grow fast, and even have edible fruit to boot. They don't look as architectural as dogwoods (Flowering Dogwoods are still my all-around favorite flowering tree), but they will grow just about anywhere. The blooms don't last near as long as dogwoods, though - (Technically, a dogwood "flower" is actually a set of bracts - really just modified leaves. That's why they last so long - We often get 2 or 3 weeks of bloom in the spring if it is cool and moist.)

My hybrid Aurora blooms in between the two species which is nice as you get two different looks with the plant.

Seems to be doing well in 7.2 ph after 2 years.

Thank you to all of you for this wonderful discussion. I think I will go with Cornus 'Venus' since it sounds like it is better suited to my area.

Jimbobfeeny, I already have two mature Amelanchier and love them. They have very nice structure, good fall color, pretty white flowers in early spring and lots of delicious fruit. We often stand by the trees picking the ripe berries and stuffing our faces, lol!

Gardenapprentice, no need to worry. Bradford pears are probably at the very bottom of my list of suitable trees. Every specimen I have ever seen looks so dull. And the scent of the flowers is horrid!

Whaas, thank you for the suggestion of the Maackia. I had never known much about this tree until looking it up after you mentioned it. It is beautiful but not quite what I had in mind for this area.

Surely doesn't take the place of a flowering dogwood but surely a nice selection for somewhere in the garden.

I've shared this one a few time before but I was always impressed with the silvery emerging leaves. They themselves looked like flowers.

{{gwi:331992}}

since we are all sharing pics lol why not share my pic. In my previous house I had a dogwood tree but since I have moved my cousin has taken control of the house, he's not much of a garden person so I don't know how the dogwood is. In fact, I don't know what variety it is (obviously c. Florida) it could be Appalachian spring or cloud nine

Well I'll see your c. florida and raise you a c. kousa in fall.

{{gwi:328795}}

And it's winter non bush-like form.

{{gwi:331993}}

tj

Meh. Still prefer Cornus florida.

I have the Venus cornus kousa in 6a Ontario. Spectacular even when young.