late season interest?

[CScott]

Which plants would give flowers or something interesting late in the season?
It seems my rock garden is over in June?    This is zone 3.
Thanks for any suggestions.

[David Sellars]

Many of the fall blooming Gentians can work in the rock garden though they can look leggy.  For a good display of colour, try Androsace lanuginosa.  It is easy to grow (though I don't know about Zone 3)  and flowers profusely in the late summer and fall.

[RickR]

Sedum cauticola is well behaved, and blooms for me now.  Campanula rotundifolia seems to bloom off and on all season. Summer blooming Alliums, like our native Allium stellatum is still going strong.  Perhaps some Colchicum spp. are hardy for you?  C. agrippinum grows well here in zone 4a.  I expect that Scilla scilloides would be hardy for you, too.

[McDonough]

CScott, welcome to the forum.  In what general geographical area do you garden?

Just starting to show its scarlet trumpets now, is Zauschneria garrettii (now Epilobium canum ssp. garrettii).
http://plants.usda.gov/java/profile?symbol=EPCAG

A bit tall and vigorously spreading for a small rock garden spot, but ideal with enough room to allow it to spread 5-6' or more, and about 12" tall, it provides brilliant color for late summer and early autumn.  I find it perfectly hardy here in USDA Zone 5, but not sure how it will do in your Zone 3 garden.  In one of the views below, you'll also see the large yellow flowers of Oenothera fremontii.  Since mine are just starting to show blooms, I post two photos from September of 2010.

[CScott]

   Thank you for the suggestions.
I am in Calgary, Alberta, Canada
Our winter Chinook winds make for cycles of warmth: thawing and freezing.
Caroline

[Lori S.]

Hi, Caroline!  Welcome to the forum!  That's a great question you pose, and one I'd like to find out more about too.
I can confirm that some of the plants mentioned are indeed hardy here:
Zauschneria garrettii - puts on a nice show of brilliant vermilion flowers up until the first hard frosts.  Z. californicum did not winter-over for me, however I tried it only once with one plant;
Colchicum autumnale and the more commonly-available hybrids are hardy here.  (I would wager you are already growing some?)
Scilla scilloides is indeed hardy... they seem to have settled into blooming yearly now, whereas they had been blooming rather irregularly before.
Some others that I have that provide some late summer/fall interest are Carlina acaulis, Heterotheca jonesii (blooms all through the season... if somewhat sparingly on my plant), Campanula incurva, Satureja montana ssp. illyrica (it has come through one winter, not sure of long-term hardiness)...
I have heard on a different forum that Zinnia grandiflora is very hardy and late-blooming - seems very promising; I only managed to get one seedling this year, and had to plant it out in what are not likely the best conditions (but hope to relocate it soon).

If you have some others that you would recommend for late season bloom, I'd love to hear of them!

[cohan]

You probably are thinking more of rock garden plants? But there are several Alberta natives flowering now and up till frost-- a couple of gentians and Gentianopsis-- crinita, for example.. could be small enough for the rock garden if you can give a vernally moist spot.
lots of Asters are in flower still, though most of these are 40cm tall and up... native Campanula rotundifolium is still in flower here, not sure about in Calgary, as are Achilleas; Erigeron spp and Gaillardia I have seen flowering very late in the foothills and a bit higher...

Sempervivums are also good for late season colour, not flowers but foliage which on many looks even better after some chilly weather

[McDonough]

Almost forgot about the genus Patrinia, until they start blooming late summer and fall.  Some are rather tall, but there are some short growing ones too.  The only one I currently grow is Patrinia rupestris, the yellow blooms starting late August and going into Sept-Oct are most welcome, and the plant has attractive dissected dark-veined leaves.  This species can be a bit large for the rock garden, but I do enjoy it... in this photo it has seeded into the edges of a garden path.  It comes from very cold places (Russia, Mongolia, Siberia) so might be a good addition to an Alberta climate.

[McDonough]

More links on Patrinia rupestris.  I have never checked out whether my plants are correctly named, but after viewing plants shown in the wild, I do believe it looks right.

Patrinia rupestris, photographed in SE Transbaikalia, Siberia, Russia. 15th July 1997
http://ftp://193.166.3.2/pub/sci/bio/life/plants/magnoliophyta/magnoliophytina/magnoliopsida/valerianaceae/patrinia/rupestris-1.jpg
Link to an image on a FTP site does not work in all cases, so in fair-use provision, I attach a copy of it below, the image titled with the photographer's name.

And a plant of P. rupestris photographed in Mongolia, photographed in the month of September.
http://www.flickr.com/photos/stationalpinejosephfourier/5054250764/in/photostream/

Flora of China entry; the species is found throughout much of china, from low to high elevations, and in Mongolia, Russia, Siberia).  Plant height is listed as 20-100 cm tall, quite a wide range:
http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200022543

[McDonough]

The best Patrinia species for dwarf habit, hardiness, and early late season of bloom, is probably Patrinia sibirica.  Here are some photo links:

http://davesgarden.com/guides/pf/showimage/311783/
http://www.filuna.cz/picture/2009-Jaroleto/Patriniasibirica.JPG
http://www.plantarium.ru/page/image/id/103706.html
http://www.plantarium.ru/page/image/id/34581.html
http://www.plantarium.ru/page/image/id/34582.html
http://fitoapteka.org/images/foto/000112/587.jpg
http://www004.upp.so-net.ne.jp/kazuhito/daisetsu/da-chisimakinreika.jpg

[Lori S.]

Excellent thought, Mark!  I do like Patrinia, and have grown P. scabiosifolia (a tall one) and P. rupestris (a more compact one)... I seem to have lost the latter though, and must try it again.  
Oddly enough, Patrinia sibirica bloomed in spring for me though*, rather than fall like the other Patrinia spp. I've grown... ??  It was only planted last year though, so who knows what it will do as it gets settled in?  Actually, I have to admit that in this remarkably wet summer, part of the plant even rotted off (yes, my tufa garden soil is too rich!  The extension of the bed will be done better!) but the surviving part looks healthy.  

* The plant in my tufa garden: 
http://davesgarden.com/guides/pf/showimage/311783/

[Lori S.]

Another thought... many of the rock garden plants that bloom in mid-summer in warmer zones, would be "late season" plants for us here, given our short season.  Perhaps that will twig some more suggestions for far north late-bloomers?

[McDonough]

Another thought... many of the rock garden plants that bloom in mid-summer in warmer zones, would be "late season" plants for us here, given our short season.  Perhaps that will twig some more suggestions for far north late-bloomers?

My mistake, I made an assumption that all Patrinia are late bloomers (like the way most or all Solidago are late bloomers), but looking up Patrinia sibirica in Flora of China, it is indeed a spring bloomer, flowering May-June.

http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200022546

It's funny that one of the image links was to your photo, I didn't realize    It's a small gardening world

[deesen]

It's been a funny old season here in Devon, a distinct lack of sun and plenty of rain. I had a quick trip round the garden yesterday getting a few pictures (and not very good ones too!) of plants that are flowering that shouldn't be. Ones I forgot to picture were a couple of small Rhododendron that have had odd flowers on them for weeks now. The Dryas in the last picture is having it's third show of flowers this year.

[Lori S.]

How bizarre, David!  I suppose I can understand the Dryas blooming again, as I see recurrent bloom on one of its parents, D. octopetala, both in the wild and in the garden, but the others seem most odd!  The Pulsatilla is especially surprising.