Arisaema

[Cgull49]

I successfully germinated Arisaema amurense, A.candidissium and A.flava this spring.  However the plants while they have developed a bit of a "tuber" - I know since my dog shook the plants out of one of my pots - have stopped growing and the stem and leaf have withered away.   The question I have is how now do I treat these pots?  Do I let them dry out, keep them damp not wet,... whatever? 

Should I put them in my cold frame over the winter or keep them in my plant fridge in the basement.  It get's pretty cold in Ottawa and I wouldn't want to lose them by not treating them properly.

[gote]

Amurense is very hardy and could be planted out unless you get colder than -20°C or thereabouts.
Candidissimum is less hardy and requires a high soil temperature; 15-17°C in order to start in the early summer.
Flavum can be hardy but that seems to be variable. Good drainage is required during dormancy.

I suggest that you log on to the arisaema list. there you can get better advice than from me.
Google Arisaema and you will find it
Good luck
Göte

[Lesley Cox]

Hi Rob, Gote's advice is good. However, as you'll have noticed when your dog operated (I have one like that too the tubers are very tiny after just the one (germinating) year. So I'd be inclined to leave them in their seed pots for another season before planting out or repotting.

[HClase]

I  have an Arisaema question too, so I'll piggy-back here.  I have a small bed with two A. triphyllum and one A. amurense.  They have each given me a single flower for a couple of years, but no seeds until now.  There now are berries on the A. a. and one of the A. t's.  Do they hybridise or are they self fertile?

There's also an Arum maculatum clump in the same bed, one of which has also berries for the first time, but I don't expect they are likely to get into exchanging genes with the Arisaemas.  (Yes, I know no self respecting gardener in the UK would deliberately plant these, but this here's Newfoundland and, if it grows we'll try it, and anyway the seeds came from my Mother's garden - the wild part.)

[David Shaw]

The books and bulb lists give no record of Arisaema crosses or named cultivars.
We have quite a number of species in the garden and, although we are fairly new to Arisaema propogation, I am not aware of them crossing. The intersting thing to watch for this year is whether or not the berries ripen

[rob krejzl]

Not an Arisaema enthusiast (can one be a luke-warmiast?), but Hinkley's book, 'The Explorers Garden', certainly talks of a hybrid between A. takedae and I. sikokianum - pictures of which I remember being posted on another list.

[Paul T]

Yes, Arisaema can hybridise.  I don't know how common they are, but they CAN happen.  They've been discussed at times on the Arisaema Enthusiast Group email list, although the purists are somewhat aghast that anyone would want hybrids. LOL  I have seen photos of sikokianum hybrids that have the white "golf ball" spadix but differences in leaves/colour/growth habit etc.  I also have a vague feeling that amurense and triphyllum are fairly closely related as Arisaema go, but I'd have to look that up to confirm.  I think that usually they don't hybridise without intervention of some kind, so they are likely to be pure I think, rather than hybrids between the two.  At least that is what I have heard from others.

The other possible reason that they haven't set seed before is that the sexes may not have been right.  Conditions and size of tubers etc can govern in some of the species as to whether the flowers are male or female (or both on the same spadix), so maybe the conditions were right this year for you to have both sexes in the flowers and therefore pollination?  I guess you'll just have to grow on the seedlings and see what they turn out like!! 

Is that a help?

[Diane Clement]

I have a small bed with two A. triphyllum and one A. amurense.  They have each given me a single flower for a couple of years, but no seeds until now.  There now are berries on the A. a. and one of the A. t's.  Do they hybridise or are they self fertile?

Most arisaemas are single-sex but changeable through the years - male when young and female when older.  So they can't usually be self-fertile (the exception is A flavum).  Unfortunately, berries don't necessarily mean seed.  Several of my arisaemas make good red berries but often there is no seed inside the berry.  What I have never been sure about is whether different plants of the same clone (from offsets) can produce seed.  It's never happened yet, so probably not.  I think hybrids are rare in arisaemas but not unheard of ...

[HClase]

Thanks everyone.  I hadn't realised that the flowers of this group (Arums too) are unisexual, so the only source of Arisaema pollen would have been the one triphyllum that hasn't berries.  We'll see later if there is any seed in the amurense berries - they are still green at present.  If there is seed, then it more or less has to be hybrid, so it will be interesting to grow these on.  Will I live to see the flowers I wonder!

(Oops, I see I have been getting my genders wrong - Arisaema is obviously one of those neuter nouns that looks feminine!)

[rob krejzl]

 "I think that usually they don't hybridise without intervention of some kind, so they are likely to be pure I think, rather than hybrids between the two."

Have to say Paul that the thrust of Hinckley's anecdote was that there was no deliberate act of hybridisation - just two young plants grown in proximity.

[David Shaw]

Perhaps I should have suggested that I have found very little in the literature about hybridisation. The Gusmans in 'Genus Arisaema' devote two pages out of 400 to the topic and would seem to imply that they seem to occur mostly in the wild with Japanese species.
I think that garden grown Arisaemas will come true - but there is always the exception to the rule.

[rob krejzl]

I know it's probably my ignorance that makes me say this, but surely caution says that, if some can hybridise naturally, one should assume all can until that assumption is disproved? After all nature doesn't generally erect genetic barriers to hybridisation if geography will do the job more cheaply.

[gote]

A possible reason for the absence of berries is that the plants are not big enough.
Most arisaemas succumb to my winter temperature so I do not grow many but a A. maximowiczii that has flowered for several years - every year a little larger - is finally setting berries this year. I have only one so there is no cross pollination. Whether there will be viable seeds inside the berries is too early to say.
Göte
 

[HClase]

What kind of temperatures do you get Göte?   Here the lowest is usually around -15C with -10C fairly frequent - although we have had as low as -24C on rare occasions.  How serious the cold is depends upon the snow cover too.  Our problem is the short summer, with the leaves appearing on the trees in the first week of June, while the late Narcissus are flowering!  In recent years the first serious frost hasn't been until early November though, the autumns have definitely been getting warmer.  (Captain James Cook is reputed to have said "Newfoundland hath but three seasons, July, August and winter.", things have improved a bit since his time here!)

[gote]

It varies a lot.
We may have -20 for many days some years some years it is hardly ever below 10.
However, this is not a very good indication of hardiness. The time of the year for the minimum temperature is important, the possible snow cover in those days etc .
Göte