First post here. Hi people!

I'm something of an enthusiast of the Southwest in North America (northern Mexico, Arizona, New Mexico, southern California, the western part of my state of Texas) and I couldn't help but notice an apparently complete lack of conversation concerning what appears to be, at least from over here in America, the most widely recognized cactus (perhaps apart from the prickly pear): The Saguaro. I was wondering recently if it had ever been brought to Australia, but Google searches didn't seem to yield anything. While I wouldn't want to encourage the introduction of another potentially invasive species to the continent, the thought of Saguaro forests stretching through the deserts of the outback, or at least growing in small gardens, struck me as rather interesting.

So, that said, is anyone here aware of any cultivation of the Saguaro cactus in Australia? And if so, are there any pictures available? : D

By the way, if the name is not enough, here's the Wikipedia article on it: http://en.wikipedia.org/wiki/Saguaro

G'day Procrascticus, and welcome aboard.

To my knowledge, and despite its iconic status, the Saguaro is little-cultivated in Australia. I've seen seedlings offered for a sale a few times, but I've never bought one.

It's my understanding that it's quite slow growing and a bit fickle in cooler climates. Have you had much luck growing it?

Well thanks for the welcome, Lachy.

It's unfortunate to hear that Saguaros aren't in much cultivation, but at least they're available in Australia. It is very slow growing--it can take at least a decade to reach six inches (about 15 centimeters) and three decades before it's even two meters high. I've been growing several in a window for about ten years now, and none have grown more than five inches, I'd say.

Cold sensitivity is rather poor, according to a page from the Friends of Saguaro National Park, which says that the northernmost boundary of the species is near Tucson, Arizona, a city that (according to Wikipedia) is coldest in January with an average low that does not go below freezing. Apparently, the coldest temperature seen in that city was close to 10 degrees Fahrenheit, about -12C, so it stands to reason that's probably near the cold tolerance limit for fully grown Saguaro.

As I said, I've grown some in a window for a while now. They were doing very well a few years ago, but began to crowd each other out, I didn't get to them fast enough, and now I've only got about three of them left. I'm sure they'd be doing well if I'd just acted a little sooner, but I guess I kind of missed the boat there. Oh well.

If you happen to be interested in trying to grow some, it's really very easy; just put them in a window and water them a few times a month(but don't quote me on that). As long as you keep them at room temperature and prevent crowding, I can't imagine you'll have any difficulties. And if you can wait about fifty years, you'll get some lovely flowers!

I think the combination of poor cold-tolerance and slow growth probably limit the appeal of a plant like the Saguaro in general cultivation here. By and large Australian gardeners haven't really embraced the idea of cacti as garden plants just yet, with most of their cultivation being limited to a few specialised arid garden plantings, and the plants that are generally chosen are fast growers like Cereus peruvianus, Trichocereus and Opuntia species. It's a bit of a shame really; I find the slow growers to be some of the more rewarding plants. That said, I must confess that when I planned my cacti garden one of the major factors I looked at was rapid growth and good cold/wet tolerance... which has led to me planting Cereus, Trichocereus and... Opuntia.

I must say, it's completely understandable to go with faster growing plants. After all, who seriously wants to wait several decades for a plant to flower, or even a couple of decades for it to just grow to a respectable size? The ones you've mentioned seem like they'd make a pretty interesting cactus garden, regardless. If my Google searches were correct, each of the three cacti you planted produces something edible. Have you gotten to eat any fruit yet, or maybe eaten the pads of the Opuntia? Weed as it may be in Australia, prickly pears make for some pretty good eating, I'm told.

As for growing Saguaro, how much of Australia do you think would really be a poor area for it to grow, aside from the tropical areas to the north and the more temperate areas from NSW to Tasmania and southern South Australia? I was under the impression most of the continent rarely saw temperatures very far below freezing. Surely it would do well somewhere like Perth?

I've eaten the fruit of Hylocereus and Opuntia ficus-indica. The Hylocereus fruit is awesome - although my plants are probably growing in too cold a climate to produce any fruit. Opuntia fruit are okay, although getting rid of the glochids is a pain, literally.

I'm eager to try the pads of the Opuntia; again getting rid of spines and glochids may be a small issue. I may try some young pads thinly sliced and stir-fried in burritos this summer.

As to the question about the climate: I suspect that the Saguaro would grow really well in Australia's more arid centre and possibly in the drier areas up north (everything seems to grow well up there although the high rainfall may pose issues). I live in the southeastern corner of Australia and I find that many species struggle to grow in the ground here due to our cold (albeit rarely freezing) winter with its rainfall. Growing in pots is a different story as they can be moved under cover; however growing a majestic species like the Saguaro really should be done in the ground in my opinion.

should graft them to a cereus understock lol

Holy.... that's so obvious, I'd never even thought of it! I'm quite used to the idea of grafting slow-growing mexican miniatures, and I've even seen the odd Trich peruvianus grafted to Pereskiopsis. But grafting Saguaro... never even occurred to me.

So what would be a suitable stock? Trich pachanoi? Cereus peruvianus?

Has anyone ever attempted this?

Lachy - Yes, I'd be more than slightly worried about eating a cactus spine if I tried eating prickly pear pads or the "pear" itself. I actually haven't done it yet, though I think I will soon, and I hope it works out for you when you get to it. Concerning climate again, that's about what I figured, then, but it's too bad your specific weather is restricting. And you're right about potted Saguaros; it's like potting a tree. Not very practical at all if you want it to get to any real size, among other things.

TasV - I'd have never given any consideration to that, amateur as I am with this stuff, but it looks like you've really piqued Lachy's interest! To Google!

(Just so I'm clear though, what would the benefit be of grafting these two together?)

Well grafting can provide two benefits. One, it makes a plant somewhat more resistant to environmental factors like excessive rain. Trichocereus and Pereskiopsis are great for this; in fact perry is so water resistant that it can even be grown with its roots more or less constantly wet - I challenge any other cactus to survive this! Two, grafting a slow growing scion onto a fast growing stock will "pump up" the scion and increase its growth rate. Again, slow growers like Lophophora, Ariocarpus, Aztekium, etc are often grown this way so seedlings can grow into large plants within as little as a year. Similarly, this will also speed up flowering which can be particularly useful if seed production is a goal.

Be the first to give it a go Lachy

http://cgi.ebay.com.au/SAGUARO-CACTUS-Carnegiea-gigantea-20-seeds-/220605029338?cmd=ViewItem&pt=AU_Plants_Seeds_Bulbs&hash=item335d159bda

Nooo.... must resist.... foul temptress...!

go on.... you know you want to

On another note... I've bought LOTS of seed (mostly Australian natives) off this seller. He's one of only two places on Ebay that I will buy seed. It is always EXCELLENT.

Seriously, you've seen hylo, harrisia and myrts rooting in water?

They'd have to have some decent callus formed before trying that. Man, I'd be terrified of rotting them. And hydro ariocarpus? Whoa...

Any pics of the peruvians and pachs in cold climates? The one in the dandenongs has piqued my interest.