The link below provides the picture I promised. The picture is down the page a ways.

LariAnn

Here is a link that might be useful: Alocasia robusta bloom

That's quite stunning, LariAnn. Thanks for sharing this.

BTW, great site--I enjoy reading about the crosses and seeing the photos on your site.

Today (April 15) I completed the reciprocal crosses with A. robusta, A. odora, A. macrorrhizos "Borneo Giant", A. portei, and A. sarawakensis. This is what I call a "full spread" hybridization series and I have high hopes for one or more of them to succeed. The A. robusta produced an ample supply of pollen for all these crosses, so now it is a waiting game. Within a month I will know if something really BIG is coming down the pipeline. I have added a second picture showing the pollen drop on the A. robusta inflorescence. Needless to say, this pollen went to good use! Stay tuned. . .

Here is a link that might be useful: Alocasia robusta bloom pictures

Very interesting, but I guess I am one of the only people that feels the pollen would be put to better use increasing the genetic diversity of the robusta population in the states rather than hybridization....but I am just not a hybrid person...one of the few I know!!

I notice that the one actually flowering appears to be in a normal plastic nursery pot.....is this the case?? If so, why do you suppose the other grower has been able to succeed without the need of the pots you use?? These are really interesting pots by the way....are they commercially available?? Does the other grower also use microorganisms in his growing??? These would be interesting points for those that want to grow a robusta themselves (not me, but others might have more of a chance in climates more suited to it). Best of luck with your hybrids, I am guessing there is a market for them :o) Dan

Dan,
You are correct that the A. robusta in bloom is in a standard nursery pot. The other grower succeeded by playing the odds; i.e. if you pot up 50 A. robusta, for example, you might get one to survive even if conditions are not ideal. The A. robusta plants this grower used as starts were tissue cultured and that means the possibility of somaclonal variation playing a major role. I have noticed this with my own batch of TC robustas; some survived while most succumbed. The airpot and microbes seem to tip the hand towards survival. Out of 72 plantlets, the six robustas I potted into airpots have survived, while of the rest not grown in airpots, only a few (3) survived, even with the help of the microbes.

This grower does endeavor to use more natural methods of pathogen control, although I have not discussed the exact products used. He does grow all his aroids in greenhouses and with a Dosatron fertilizer injection system feeding each plant individually through dripper tubes. And yes, he does lose his share of the difficult Alocasias, even under his professional conditions.

As far as I know, airpots are available from only three sources; wholesale, from Florikan, US west coast retail from Tree Amigos, and US southeast retail, Aroidia Research.

As far as the pollen being better used to "increase genetic diversity of the robusta population in the states" is concerned, I had only the one inflorescence to work with as the first one was completely spent by the time I saw the plant for the first time. This would require at least one additional blooming plant from a totally unrelated robusta population in order to "increase genetic diversity", but even so, I would be inbreeding the population, or homogenizing it, rather than increasing diversity, IMHO.

LariAnn
Aroidia Research

Here is a link that might be useful: Air-Pots

Thanks LariAnn!! I will look at these air-pots...a really nice idea!!! I have read your many posts that these are really tough and I only have a few common X-ocasia that I toss in the yard every year, but I have to hand it to you guys that can grow these on :o)

I guess I assumed the plants in question were of diverse genetic heritage rather than all coming from the same source when I mentioned increasing genetic diversity. Hybridization is not increasing genetic diversity of a species of course, but it is truly fascinating what can be had from mixing chromosomes I have to admit! Keep up the good work and please do let us know what happens with the seed set :o) Dan

Update on the hybridizations involving A. robusta:

Of all the crosses I performed, so far one of the A. odora x A. robusta is setting berries; the other is aborting. The A. portei x A. robusta, A. 'Big Mac' x A. robusta, A. robusta x A. 'Borneo Giant' and A. robusta x A. odora have all aborted as well.

However, with the success of A. odora x A. robusta, tentatively to be called A. x "Robudora", a truly robust, hardy, and giant Alocasia for the amateur grower is not very far off now.

LariAnn Garner
Aroidia Research

Really enjoy reading about what you're doing, LariAnn, and hope you have continued success. Keep us up-dated please!

As do I. Looking forward to more progress.

I am growing A. calodora and A. portora here in N. California. So far so good.

The berries from A. odora x A. robusta have ripened and have been harvested, yielding about 20 viable-looking seeds whose appearance suggests true hybridity. The process, from pollination to seed harvesting, took almost exactly two months. Within a few weeks, I will report on the appearance of the plantlets, but I am confident they will show that this cross did, indeed, work.

LariAnn
Aroidia Research

Here is a link that might be useful: Alocasia robusta page

That is really exciting LariAnn!!!!
I was thinking about this just the other day and wondering what was going on. I canÂt wait for the next update!!!

Jane

New update information; the hybrid robusta seeds have begun germinating, but still too early to tell what I've got.

More importantly, I've posted new information about results I am getting from planting Nephrolepis ferns in with my A. robusta. I will be posting pictures as the results are that dramatic. For now, what is happening is the A. robusta with the fern is holding leaf blades nearly completely erect, or perpendicular to the soil, while the A. robusta without a fern is holding leaf blades at 45 degrees to over 90 degrees away from vertical. Same shade, watering regime, fertilization, soil mix. The behavior of the one with the fern most closely matches some of those I've seen in native habitat pictures (which, incidentally, include the Nephrolepis ferns in habitat as well).

I've added Nephrolepis ferns to a few more A. robusta to see if the effect continues. Also, have used water leached through the root balls of the ferns to water A. robusta without ferns, reasoning that the "active principles" may be soluble and yield their results even in the absence of the actual fern.

LariAnn Garner
Aroidia Research

Here is a link that might be useful: Alocasia robusta

That is really cool that they are starting to germinate!! I wish you much success!! It will really be neat finding out just what you have. I REALLY appreciate you posting your results and finding and the link to the web site here! I am always checking here to see if you have posted anything new.

That is really interesting about the fern. I hope you can figure out just why they make such a difference.

Leave it to me to fall so hard for tropicals in the zone I live in. I really need a bigger place and a greenhouse. I guess IÂll just be thankful I have an extra room with two windows in it.

Jane

Below is the link to my pictures showing the dramatic difference in growth habit of the A. robusta when planted in a pot together with a Nephrolepis biserrata "Macho Fern". The pictures speak for themselves.

Even though this work is ongoing and not entirely conclusive, this is what's happened so far so those of you who have A. robusta just hanging on may choose to try it for yourselves and see what happens.

LariAnn Garner
Aroidia Research

Here is a link that might be useful: Alocasia robusta plus Nephrolepis fern trial

Sorry! I typed the link in too fast and messed it up - this link below will work.

LariAnn

Here is a link that might be useful: Alocasia robusta plus Nephrolepis fern trial

Ok, now that is really wild. I canÂt believe what a difference it makes.
Oh and by the way I was drooling on my keyboard over the first picture.
You have to wonder if the fern roots add something or take something out of the soil and that is what makes the difference. This is really interesting!
Thank you so much for the update!

Jane

I usually hang out in the Texas forum. I've been growing giant elephant ears for several years. Each year, they come back smaller.

However, there are some people from north Texas, zone 7, who have had nothing but great luck with their elephant ears. They come back more robust each year.

Upon looking at a photo, they were growing colocasia.

I know that I'm growing alocasia, m....(something or other.) Upright leaves with a stem going staight through the leave. Very glossy, extremely large leaves.

Now, the question. Plants Delight, which is based in North Carolina lists the hardiness of Alocasias to zone 7.

I disagree. My alocasia even bloomed after returning last spring, but it never regained the previous vigor. This is it's 3rd year and it's leaves are even smaller.

Just wondering if you know what the actual hardiness of alocasia is?

As for hardiness of Alocasia species, many species vary in their hardiness. In my experience, the hardiest of the lot is the Alocasia odora, which is why I chose it as the basis of my hybridization work with Alocasia. The varieties of Alocasia macrorrhizos are, in my opinion, not nearly as hardy as A. odora.

The most important thing to remember, though, is that the genus Alocasia is, after all, a tropical genus and so even if some species can tolerate a less than tropical winter, that is not their preferred environment. Keeping that in mind will help to avoid disappointment if a plant doesn't take to the colder winter environment.

In any event, I would always dig up the plant each fall, keep the tuber dry in a frost-free location or pot it to keep indoors if you have the right conditions, reincorporate more organic matter into the soil after frost is past in the spring, then plant outdoors and treat the plant to superthrive and organic fertilization each spring/summer season. Oh, and make sure it doesn't dry out in the dog days of summer.

LariAnn Garner
Aroidia Research

Here is a link that might be useful: Alocasia odora

Some updates on both the hybrid A. robusta seedlings and the Nephrolepis fern work:

As of this past weekend (July 14), most of the hybrid A. robusta seeds have germinated, but the seedlings are still too small to display identifying characteristics. Their slower development, when compared to selfed A. odora seedlings, is one indication of hybridity.

I have planted several more Macho Fern plants in with other A. robusta plants I have at Aroidia. Two A. robusta in particular are just about at death's door due to root and corm rot, but after removal of necrotic tissue and disinfection, I planted each of them in a separate pot together with Macho Fern divisions. Should they begin to rally, I will chronicle the progress with pictures. Right now there is nothing to see, as one of the robustas has no leaves and the other has one leaf just hanging on.

Another, much healthier, A. robusta that previously had no fern with it now has one, and the leaves have begun to show a more erect posture. In a few weeks, hopefully, the results will be dramatic enough to illustrate via pictures.

LariAnn Garner
Aroidia Research

Here is a link that might be useful: Alocasia robusta at Aroidia

Hi all,

I've posted a new picture on my Alocasia robusta website showing what the plant looks like after about six weeks with the Macho Fern planted in with it. I think it's worth a look!

LariAnn
Aroidia Research

Here is a link that might be useful: Alocasia robusta - Nephrolepis fern trial

That's pretty fascinating, LariAnn. Looks like a good symbiosis.

Hello,I'm collector of conifers, but I'm interested by Aocasia or Calocasia for my garden.
Somebody know a hardy specie or cultivar for zone 7 ?
Clément

To be honest with you there aren't many Alocasia that are hardy bast zone 9. But Most colocasia's are hardy in your zone. you might also look into Xanthasoma.

Thank you, please let me know some exemple ?
Clément.

Try Colocasia 'Pink China' from Brian Williams. He says it's hardy in Zone 6.

Alocasia Odora is pretty hardy. Also, you could try c. escuelenta 'Black Magic', c. e. 'Ruffles', c. 'Fontanesii'. See Plant Delights: plantdelights.com

Here is a link that might be useful: C. Pink China

Update on Alocasia robusta hybrids (A. odora x A. robusta):

The plants are now about 6 inches tall and are showing the brownish petiole coloration that is typical in young A. robusta plants. Since young or old A. odora plants have no coloration other than green, this observation is conclusive confirmation of hybridity.

These plants should really take off as the weather warms.

LariAnn
Aroidia Research

Glad to hear the hybridizing went well. Looking forward to photos of them down the line.

Thank you very much philofan !
Clément.
Belgium

Interim A. robusta hybrid update:

The warmer weather spell we've had the past few weeks has shown on the hybrid plants, as they have accelerated their growth. New leaves are significantly larger than the previous ones, and they are following one another rather quickly. This observation has me very excited for their potential growth and ultimate size this Spring and Summer.

The overall look of the leaves is unlike those on a selfed A. odora seedling; the petiole coloration varies from extensive to barely noticeable on some plants.

I will try to post pictures within a week or so, including a pot with A. odora selfed seedlings for comparison.

LariAnn
Aroidia Research

Interesting developments, LariAnn. Looking forward to the photo update.

Alocasia x robudora photo update:

Here's the picture you've all been waiting for!

This picture shows four of the Alocasia x robudora seedlings, now in their own 6" pots and growing vigorously. Note that the petiolar coloration is visible on some of them, but not as defined as is found in the species A. robusta.
{{gwi:383300}}

LariAnn
Aroidia Research

See the new thread, "Alocasia robusta in bloom II - the sequel!", for more about what I'm doing with A. robusta.

LariAnn
Aroidia Research

That's awesome LariAnn,
I'm glad someone figured out how to make the A.robusta do well, great thinking.
With all the cold hardy Alocasia hybrids your creating, have you attempted or thought of any cold hardy Colocasia hybrids? A C.'Jack's Giant' or C.gigantea'Thailand' crossed with a C.'Pink China' would be awesome for a hardy giant.
I'm glad someone in an area that is good for blooming is creating cold hardy Alocasias for us northerners!
Thanks again!

I do not have a breeding collection of Colocasia, as I have specialized in Alocasia for years. Others are breeding with Colocasia, including a fellow in Hawaii and Brian Williams in Kentucky. I agree that work with the C. gigantea would be exciting, although the leaf texture is rather thin for my taste. I prefer a thicker, more durable leaf, and I have succeeded, especially with my Alocasia 'Imperial Giant', which has a very large, heavy textured leaf.

LariAnn
Aroidia Research

This is a great resource... Thank you...

I'm a hobbyist in San Diego that loves to grow Alocasias & Colocasias, though more interested in very large Alocasias.

I built a new greenhouse (wife thinks IÂm crazy) and am looking for additional seeds and/or small plants to grow. Also learning more about humidity and lighting resources so any great suggestions on resources would be greatly appreciated.

Are their groups that trade or donate seeds and/or small plants?

Look forward to hearing back.

mgalvin@san.rr.com

michaelg