Iris cristata and small woodland Iris

[Hoy]

I have never tried it over here, Mark, but if I get the chance I'll give it a try both at home and at my seaside cabin.

[Todd Boland]

I don't think hardiness is a problem here...I just don't seem to have the right conditions...frost heaving is a b***h around here and Iris cristata with its rather shallow roots, gets nailed.  I think we have one member in our society that grows it in her actual woodland, among Cornus canadensis, Clintonia borealis and Trilliums.  She can also grow Soldanella, another species I have absolutely no luck with.

[Lis Allison]

Could snow cover be a factor? I moved a clump of I. cristata to a place in my rock garden where it doesn't stay covered with snow all the time, and it died totally. Other patches, in the woods or another part of the rock garden that is snow covered all winter, are doing fine.

[RickR]

I hardly give Iris cristata a second thought here, just like Mark.  It does its thing without any special care.  At least for Todd, outright cold can't be the deciding factor.  He has warmer winters than me.  The only thing I have found with Iris cristata is transplanting in fall is usually deadly.  But that's apparently not so uncommon in that iris section or with bearded irises.

Iris lacustris is carefree here, too.

[McDonough]

Rick, I think you hit the nail on the head, late planting is fatal with them.  In my photo exposé of dividing and planting Iris cristata, the exercise took place on Jun 21, 2010.  This is a point after flowering where new rhizomes above the soil have expanded and just starting to tap down into the soil with "anchor roots" (the photo of an uprooted division shows this), the best time to divide.  Since the rhizomes basically sit on top of the soil, they depend on well developed and mature "anchor roots" to get them through the winter.

Last winter we had much less snow and I photographed the bare ground where a large patch of Iris cristata 'Shenandoah Sky' grows under a Stewartia pseudocamellia tree. In January & February I'd look at the exposed rhizomes and cringe, but they do just fine. 2010 was an exceptionally early spring, here is the bare mass of rhizomes in March.




Close by I have an old clump of Iris gracilipes "Buko Form", a tiny miniature form with white flowers.  Since it was an early spring, I got over anxious and cleaned up the old foliage, which makes a thatch concealing the budded rhizomes.  It was a mistake.  A day after the cleanup, we had a deep freeze, and slowly over the next few weeks, parts of the large clump starting dying off.  Eventually I only saved a small piece... fortunately I had a few 2-3 year seedlings coming along. A friend warned me the year before, "you really should divide up that clump", but I got lazy and didn't do it.  The seedlings had no problem with the sudden cold snap.




Next to it I grow Iris gracilipes 'Cobblewood Charm', a hybrid by Darrell Probst of "Buko Form" with the regular larger I. gracilipes.  It too had no problem with the cold snap, even though I cleaned up the thatch.  While the emerging rhizomes of the "Buko Form" and 'Cobblewood Charm' look the same size, the "Buko Form" ones are minuscule!  My attempt at getting a good side by side comparison photo didn't work too well, so in the last shot I overlaid the image of 'Cobblewood Charm' at the same scale, to be closer to the "Buko Form" 2-3yr plant, to show the difference in shoot size.

[RickR]

It was a mistake.  A day after the cleanup, we had a deep freeze, and slowly over the next few weeks, parts of the large clump[of Buko Form] starting dying off.  Eventually I only saved a small piece...  The seedlings had no problem with the sudden cold snap.

Mark,
Did you do anything to "save" the remaining Buko Form, or just let nature take its course?

And had you cleaned the seedlings too, and they still sruvived?  Maybe there just wasn't much old foliage for protection anyway.

[McDonough]

Mark,
Did you do anything to "save" the remaining Buko Form, or just let nature take its course?
And had you cleaned the seedlings too, and they still survived?  Maybe there just wasn't much old foliage for protection anyway.

Yes, I tried to save it, divided up the entire clump and replanted smaller pieces, but the growth points just sat there and most shriveled away.  I got only one remnant piece to survive.  The super hot & dry summer didn't help, even though I watered the divisions religiously.

The 2 & 3 year seedling plants had been "de-thatched" too, but were okay with the sudden deep freeze.  I think the mother plant's rhizomes had just become too large, dense, and weakened with age, and were in need of division years before.

[McDonough]

A few repeats, but they are all so comely this season that I snapped some photos.  Does anyone get Iris cristata seeding around much?  I rarely get seedlings, even with lots of seed-filled pods typically produced, but I hypothesize these largely get eaten, they seem a favorite of squirrels and chipmunks.  But a do have a few self-sown seedlings, here's one that is flowering for the first time, nothing special, just a nice light slate blue.




Two Iris cristata forms in opposing forms, both are the earliest cultivars to bloom.  The first set of photos is 'Sam's Mini', very low growing and neat, excellent low arching foliage, and highly floriferous.  A strong fast spreader too.  The second set of photos is 'Edgar Anderson', the relative GIANT form, also making fine foliage mats but much larger and taller, and floriferous with crystalline frilly-edged mid blue flowers.  Exploring cultivars such as these is a good reminder just how variable a plant species can be, and gardeners certainly do horticulture a service by recognizing these differences and embracing the more unique forms.  It is worth noting, all Iris cristata forms survived last year's record breaking drought without a scratch.

Iris cristata 'Sam's Mini'


Iris cristata 'Edgar Anderson': the 2 photos on the right in early morning sunlight, making the flowers appear more blue.



The flowering of Iris henryi (left) was somewhat ruined by extended periods of rain, and I missed much of the flowering while I was traveling, managed to get a snapshot one rain morning.  Same with yellow Iris minutoaurea (right).  This one is starting to flower less, I believe it needs to be divided and replanted to "refresh" the plants for better growth and flowering in  the future.  I. henryi is also earmarked for division.

[McDonough]

Looking around the garden recently, I noticed how different some of the leaf forms of Iris cristata can be.  In the photo on the left is I. cristata 'Shenandoah Sky', with fairly broad leaves with gracefully arching tips.  In the photo on the right, you can see 'Shenandoah Sky' on the left side of the photo, and in the center foreground is I. cristata 'Mountain Girl', with bold narrow-leaved sharp fans of foliage; quite a different look about it.  On the upper right is I. cristata 'Alba' with the more typical arching leaves.

 

[McDonough]

My original Iris odaesanensis has flowered poorly the last couple years, barely at all.  So I'm trying them in various spots in the garden to find a spot more to its liking.  In this view, is a seedling grown plant, which actually flowered this year (4 yrs from seed) with a couple white flowers.  I noticed that in late summer and fall, the rhizomes bulk up with lots of narrow blue-green fans and shoots... I think they take a while to become established.

[Lori S.]

I'm not sure how I missed this thread earlier, but your irises are just incredible, Mark!   

[McDonough]

These Iris are such easy-doers here... pot up an Iris cristata form and try to sell it for 1$ or even just 50 cents at a New England NARGS meeting, and it's like trying to sell some weeds, no one wants them because they're so commonplace here.  I find them all totally delightful and satisfying regardless.

[RickR]

I potted up some Iris cristata in the spring a few years ago and forced them the following winter very successfully with just natural light.  They were blooming door prizes at an early March NARGS  Minnesota chapter banquet.  Bill Dougherty of Summer Chase Gardens spoke on iris.  He is very good.  Iris that I potted up in late summer/early fall did not survive.

So if you have an overabundance, you can play with them in the winter, too.

[WimB]

These Iris are such easy-doers here... pot up an Iris cristata form and try to sell it for 1$ or even just 50 cents at a New England NARGS meeting, and it's like trying to sell some weeds, no one wants them because they're so commonplace here.  I find them all totally delightful and satisfying regardless.

 

Just come and sell them over here, Mark. You could ask 5 euro's for a pot of I. cristata and they'll sell very easily...

[McDonough]

Just come and sell them over here, Mark. You could ask 5 euro's for a pot of I. cristata and they'll sell very easily...

True enough, but it would probably cost 10 euros per pot to ship them

Funny how in a global context, some plants receive little fanfare while elsewhere the same plants can be coveted.