leaf cuttings Amorphophallus linearis

[Aad]

My Amorphophallus linearis is still active. I don't want to disturb the plant to see if the tuber I received from the pbs exchange has grown and made new offsets. I found this online description of propagation by leaf cuttings (https://www.juniperlevelbotanicgarden.org/propagation-of-amorphophallus-by-leaf-petiole-cuttings/). However A. linearis is not mentioned. Besides that never done it before on any kind of Amorphophallus. Is it worth to give it a try at this time of year (end of summer). Any other suggestion how to proceed are welcome.

[Uli]

Hello again, Aad,

My Amorphophallus linearis is a former leaf cutting.
My mother plant has flowered and not produced a leaf so far this season. No seed set, though.
For a leaf cutting you need a segment of the leaf which is branching. My own attempts to propagate it this way have failed, though. It was given to me by a friend from a botanical garden who has all the perfect conditions at hand. Vegetative propagation by offsets is very slow. The plant produces a very long and slim tuber and older plants need a very deep but rather narrow pot.

[Steve Marak]

Hi Aad,

I've been propagating Amorphophallus this way for more than 30 years now, but just casually, to make plants to give friends. The PDN link you posted is by far the best write-up I've seen, and has data on the most species. They're the experts.

A couple of comments. PDN removed 2/3 of the leaf, leaving 1/3 to provide energy to the existing plant. I've never been that brave, and always stop at 1/3. For larger species, that 1/3 can be divided into 2-3 cuttings (or more), as they did, but for smaller ones I just leave it a single cutting. I have no scientific data to support this statement, but it seems reasonable that there is a minimum leaf area needed to collect enough energy to produce a viable tuber before the natural senescence of the leaf occurs.

Timing of the leaf cutting seems important. PDN suggests waiting about 4 weeks after leaf emergence to take cuttings, and I'd agree. But at some point, as the leaf ages, the likelihood of success from cuttings of it goes down dramatically, and my experience is if there's the slightest bit of yellow, indicating the leaf is beginning to senesce, there's no chance at all. This still leaves you usually some weeks of viability, but don't want too long.

Without a commercial propagation setup like Tony's, after application of rooting hormone I stick them in damp perlite and put in a plastic bag (ziploc) with the top folded over but not sealed, and in bright light but not direct sun. Then wait. Don't let the medium dry out. Eventually the leaf turns yellow, collapses, and disintegrates, just as it would on the plant, and that's when I dig into the perlite to see if there's a tuber or not.

Good luck!

Steve

[CG100]

Every day is a school-day.

Never heard of Amorphophallus being propagated via leaf cuttings before.

Assuming that all Amorphophallus are actually Amorphophallus, is this possible with all species?

(The "usual" Genera - Lachenalia and Eucomis - are very easy, although I did not realise until after striking my first leaf cuttings, that the cut leaf sustains the forming bulblets through the first season, so you see nothing of the new plants until the following year, when they make their own leaves.)

[Aad]

I think the cutting is too old and it is too far in season to accomplish a successful propagation. I removed one of the two branches and all but two leaves on the remaining branch. But no guts no glory.

[Steve Marak]

Every day is a school-day.

Never heard of Amorphophallus being propagated via leaf cuttings before.

Assuming that all Amorphophallus are actually Amorphophallus, is this possible with all species?

It's a big genus spread from Africa to Australia and a wide range of habitats, and probably many have never been tried. But it seems most can, though the success rate varies widely from species to species. Oddly, to me anyway, A. konjac, which is the hardiest (it's survived -20 F [-29 C] in the ground here several times), probably the most commonly grown, and which offsets prolifically, is rather difficult to propagate from leaf cuttings. Others, like A. parvulus (now harmandii) are almost 100% if the cutting is taken at the right time. I've not tried any of the really tiny ones like myosuroides or ongsakulii.

My experience is that rooting leaf cuttings of the tuberous aroid genera in general varies widely. I think every leaflet of Gonatopus boivinii that falls off and lands on soil will root and form a tuber with no help. I used to find them all over the place in the sun room. But I've tried leaf cuttings of Taccarum weddellianum, several times with no success. I've also failed with the very few Arisaema leaves I've been willing to sacrifice to experimentation, but I think Tony has had some success in that genus.

Steve