So, in the mountains, the bloom season is fairly extended through the (albeit brief) summer due to the elevation and other conditions....
But (and I'm making sweeping generalizations here), in our troughs/rock gardens at lower altitudes, correct me if I'm wrong but spring tends to be the big bloom time. Surely, though, it is possible at least to some extent to plant rock gardens the same way as we do perennial beds... that is, for constant bloom through the season?
If I may ask, what, then, are the alpine species you have found useful for summer bloom? Fall bloom? Repeated bloom? All-season bloom?
PS I'm considering an alpine order to fill several new troughs, and needless to say, would be delighted to incorporate some of this knowledge!
Thanks!
altagardener
Extending the bloom season in troughs or rock gardens...
Good question and one I'd like more information on. I have some bulbs for early and late season with perennials for the main season but it's so difficult in troughs because you cant just hide things away when they are finished flowering!
Well, I'm not really intending to answer my own question here (and hope not to have to, LOL!), but... the smaller late-blooming alliums such as A. sikkimense and A. cyaneum could likely be candidates. They are blooming here now (though in a regular border, not a rock garden) - given their small size, though, I would consider moving them to a trough to appreciate them better...
I have a couple of small alliums that are perfect for that situation - sikkimensis, caeruleum and insubricum. In a larger raised bed I have bigger alliums (about 8 to 12 inches) such as lenkoranicum in flower now and also Oreophilum Zwanenburg and cyathophorum whish are all incresing nicely.
I just took a quick survey of my drought-stricken rock garden and noted what is flowering at the moment.
1. Ceratostigma plumbaginoides (Hardy Plumbago) is just getting started. I really love this plant: intense blue flowers, followed by purplish leaves in fall, but it would be too vigorous for a trough.
2. A double yellow Helianthemum. The label says H. sulphureum 'Plenum', but I'm not sure if that is accurate. The leaves are dark green and the flowers are small, light yellow pompoms, and it has been blooming for months with no let-up.
3. Linum perenne. Another plant I would not be without. Sky blue flowers, all summer. Upright, airy, seeds itself mildly.
4. Oenothera macrocarpa 'Incana'. Again, not sure how accurate this name is. The plant is like O. missouriensis, but with very silvery leaves. Large, silky, yellow flowers.
5. Sedum pluricaule 'Rose Carpet'. Tiny, glaucous leaves and rosy pink flowers. Would be perfect for a trough.
6. Sedum telephium 'Purple Emperor'. Upright growth, dusky purple leaves, purplish-pink flowers.
7. Serratula coronaria 'Nana'. Little, off-white, cornflower-like blooms on a low clump of leaves. A trough possibility.
8. Several thymes are still blooming, Thymus x 'Doone Valley' and T. serpyllum 'Minimus' among them.
9. Zinnia grandiflora. A late starter, now in mid-bloom, covered in little yellow "marigolds".
Other than that, there is some foliage interest, from grey artemisias, blue fescue grass, yellow berberis, and variegated yucca.
I have been most satisfied with Acinos alpinus, grown from seed. It blooms off and on most of the summer for me. And its great for troughs because it's very small leaved and spreads and drapes over the trough sides. Looking at it, you'd think it is an annual, but it comes back every year. It is in the right front of the pic.
Another late bloomer, and great trough plant for me is Sedum obtusifolium. Stems die back each winter. Although large leafed, it grows only to a length of 2-3 inches (5-7.5cm). And that includes the rosy pink blooms too. It seems to be barely winter hardy for me though, and I wonder if the late start in the spring is the reason for the later bloom.
I wonder if an annual like Nigella hispanica would stay small enough in a lean soil alpine trough. I must try that next year. I'll have lots of seed if anyone else would want to try.
Not for alpine troughs, but if you have more of a woodland theme, Thilictrum kiusianum is still blooming in my garden. And there would be miniature hosta, and Thalictrum thalictroides cultivars that are virturally continuous in bloom.
I recall reading somewhere a while back that Claytonia sibirica blooms through the summer... and then last night I found a comment in the thread "Mid-June Alpines" here, that supports that. I'll be on the look out for seeds for this one!
June, I take it that Zinnia grandiflora is a perennial where you are? I'm intrigued by this one... I ordered seeds for it from Alplains and plan to start them next year, to test for hardiness here.
And for more late-bloomers... come on, don't tell me no one out there is growing gentians????
Carlina acaulis is starting to bloom here now, and I gather it's derived from alpine regions... but since it grows just fine in regular soil, and is certainly oversized for a trough, I'll leave them there.
Zauschneria garretttii (or more properly Epilobium canum ssp. garrettii) is also in bloom now - considerably earlier than usual, due to our warm summer - would be lovely in a rock garden (though it doesn't need any extraordinary drainage here); too big for a trough though. Beaver Creek sells Zauschneria californica ssp. latifolia which is said to be 2"x8"... that would certainly be a jolt of color in a trough!
Yes, Zinnia grandiflora is perennial for me. Please note that it remains dormant until very late in spring. After its first winter, I thought it had died and I planted something else almost in the same spot...and then the Zinnia came up.
My Gentiana septemfida var. lagodechiana's always bloom in late spring/early summer. I have it from two different sources, and they both bloom the same.
Late blooming gentian, my foot!
Well, that is strange! My Gentiana septemfida var. lagodechiana (actually 2 - one in the ground and 1 in a trough) are in bloom now, possibly a tad early but not much off their usual schedule! (It and an eriogonum are the only things I have blooming in troughs right now.) And Gentiana dahurica is blooming now in the border, pretty much on schedule too.
Of the early bloomers, for me, G. acaulis is quite early, G. lutea goes in early summer, followed by G. tibetica a little later.
I picked up a few others this year, G. gelida, G. parryi, and G. paradoxa. G. paradoxa has a flower on it now, and I see from the NARGS site that this timing should be more or less the norm for it.
This message was edited Aug 19, 2007 11:21 PM
I really wonder about that guy, lago.
My G. dahurica 'Nikita' just finished bloom. Not a tidy plant, IMO.
Galanthophile - excellent thoughts on the alliums! Ahh, new species to try! (Of course, the first thing will be determining if they are hardy here. But then, since A. sikkimense is supposedly a zone 6-7 plant, yet is actually hardy here, it's clear that new plants simply have to be tried!) A. insubricum and A. cyathophorum look lovely, and A. lenkoranicum looks like it has rather interesting detailing on the petals.
I'm puzzled about A. oreophilum 'Zwanenburg'. I have A. oreophilum (syn. ostrowskianum) and they are late spring bloomers that go dormant here; is the 'Zwanenburg' variety (or our conditions?) so different that they are late summer bloomers there?
Leftwood, if that darned G. dahurica 'Nikita' is vexing you with it's untidiness, you could always send it on to me... I'm sure I'm a much less tidy gardener, and it would probably just blend in happily with the general disarray, LOL!
June - thanks for the tip on the zinnia. Your Serratula coronaria 'Nana' is quite an elusive little thing - can't find any pix on google. Any chance of a photo? I've found out that the source I'm considering ordering from has a small variety of Sedum pluricaule - will probably add it to my ever-increasing order!
Sorry, altagardener, I tried and failed yesterday to get a pic of the Serratula. My camera does not like white flowers - the blooms are overexposed blurs, though the rest of the picture is fine. If I adjust the exposure, only the flowers show and the rest of the picture is dark. I'm sure it's operator error, but I can't figure out how to fix the problem. Also, I am having trouble taking closeups because I can't bend my knees to get within the proper camera range (don't ask). Today is a very overcast day, so I'll try again - fingers crossed.
My Zwanenburg did flower late this year - in early June. Very pretty it is!
Allium lenkoranicum is a beauty - it is flowering now for me and is maybe big enough to go in the border.
This is a close up of lenkoranicum.
Hi altagardener! As requested, a picture of the Serratula coronata 'Nana' - not a perfect portrait, I'm afraid, as I have no idea how to correct the exposure to get detail of the petals. The flowers are a couple of inches above the leaves.
I forgot to include this little, annual Linaria in my list of current blooms. It came from seed marked Linaria aeruginia var. nevadense and was grown by nurseryman Keith Squires (proprietor of The Country Squires Gardens near Milton, Ont.) His plants flowered in many shades of red, orange, and purple. I bought from him a purple-flowered plant - like the one in my pic - last year, but some of its seedlings in my gravel bed this year are showing more red in their blooms. It has seeded quite prolifically, but the plants are so airy they are not a problem (yet!).
Thanks for the pix, Galanthophile and June!
Ooops, sorry, Galanthophile - I realize now that I misunderstood what you were saying about 'Zwanenburg' (i.e. that it is increasing nicely, not that it is blooming now). So things aren't that different between here and there after all, LOL! Lovely petal detail on the A. lenkoranicum! On another allium-related note, I have been trying to acquire the more interesting colors of A. flavum v. tauricum... but keep ending up with yet another yellow one...
June - that does look like a nice little plant. Must keep on the lookout for it. By the way, I have the same camera problem you mentioned (whites or brightly-contrasting colors flare) - if you discover a not overly technical solution to it (i.e. one that you could explain to your cat, and be reasonably sure that it understands, LOL!) , please pass it along to me. I like that little linaria too!
Leftwood - I agree that Thalictrum kiusianum is a heck of a good little plant! T. ichangense (just acquired this year) seems to have the same ever-blooming trait... actually, I'm not even sure what the difference is between these two... must look more closely. Another terrific bloomer for the woodland is Cyclamen purpurascens - lovely foliage too. I just installed some T. thalictroides over the last 2 years; pretty well every time I thought to look at them, they had a couple of flowers. Next year, I will expect great things of them, as they mature a bit! Thanks for the advice on Sedum obtusifolium - that would certainly provide a different look for my troughs.
One of the specialist bulb stockists I usually order from has allium flavum v tauricum so I might get one on your recommendation altagardener!
Thalictrum kiusianum and T. ichangense cannot be mistaken for each other. Although T. ichangense and T. coreanum could/would. Apparently the only difference between them is purely botanical, and has to do with the length of the pistils. Once I was able to even find the pistils, I keyed mine as ichangense.
This is T. kiusianum. These first flowers of the season are 2-3 inches high.
And this is Thilictrum ichangense. Notice the peltate leaves and much larger plant size. Flowers here are 1 foot high.
Thalictrum thalictroides 'Schoaff's Double'
Ahh, thank you for pointing out the very clear difference between the two, Leftwood. It's good to know my plants were labelled correctly.
Lovely double flowers on that one!
Here's another little cutie that's been blooming all season in the acid bed, Erodium x variabile 'Flore Pleno'; more of a woodland-ish plant too (though the one in part shade has bloomed less); hope it winters:
I did have an Erodium chamaedryoides overwinter outside once. But that was when we had an early blizzard that blanketed the ground so well that the soil never froze (or maybe the tiniest bit).
Leftwood, our mutual gardening pal from your neck of the woods, Jan, seems to be finding Erodium chrysanthum to be hardy and a very nice plant... just passing that along...
That's exciting, Alta (can we call you Alta?). I must pursue this matter.