Trichocereus terscheckii in flower, with saguaros in the background. Sometimes these two species are confused in the nursery trade, but they do appear distinctly different and have different flowering times and patterns.
Although I have five fairly large ones, ranging from 7 to 10 feet tall, my “Argentine saguaros” (Trichocereus terscheckii) do not bloom that abundantly. I currently get only 1 or 2 flowers per plant per year, even though I know they are capable of more than this. It is therefore a pleasant surprise to see a blossom, and even more so when it happens on a rare rainy day. I love the misty background, while it was still drizzling after we had received 1.2″ (3.1 cm) of rain in the late summer monsoon.
Clearing storm clouds serve as a backdrop to this T. terscheckii photo taken on Tuesday Sept 10, 2013 after 1.2 inches of rainfall.
Trichocereus terscheckii has proven to be completely cold hardy for me. I have never covered them, not even against the most devastating cold of 12 F (appx -11 C) such as what struck me for 5 consecutive nights in January 2013, and they have not been damaged. The Monte Desert of northern Argentina is quite ecologically analogous to the Sonoran Desert of Arizona, and there are many overlapping genera of plants despite these two deserts being situated 6000 miles apart in different hemispheres. In fact the two deserts look so similar that to the untrained eye two different photos of each could have been taken close together. Thus it makes sense that plants from one region will perform well in the other. Terscheckii is the most southerly-growing tall columnar cactus, and saguaros are the most northerly, so both exhibit great frost tolerance relative to other columnar species. This is a plant that any cactus enthusiast with the space should consider growing outdoors, from Central and West Texas all the way to California’s Central Valley.
A juvenile saguaro not quite 6 feet (2 meters) tall is in the foreground, while Trichocereus terscheckii flowers to the left. Note how the terscheckii will develop branches quite low on the trunk, and also branch sooner than saguaros do. Saguaros tend to not put out arms until they are at least 12 feet (4 meters) tall and seldom branch below 6 to 8 feet (2 to 2.5 meters) on the trunk. Terscheckii will grow more branches, lower down, and on younger plants, which helps distinguish them.
Trichocereus terscheckii to left, saguaro (Carnegiea gigantea) to right. The trees are blue palo verde (Parkinsonia florida) to left background and California juniper (Juniperus californica) to right foreground.
T. terscheckii has fewer but longer spines than saguaros do. The flowers are also larger and have longer floral tubes, and can bloom anytime between April and October, while saguaro flowers mainly appear only in May and June.
This view has several columnar cactus species in it. In the foreground right is a Baja cardon (Pachycereus pringlei), in the middle with one arm is Trichocereus terscheckii, the plant to the middle left is a red barrel cactus (Ferocactus acanthodes), and immediately behind that and in the background are a total of five saguaros (Carnegiea gigantea). The barrel isn’t typically considered a columnar plant, but since this individual is almost 6 feet tall and fits the theme of the image, I’ll rank it as one despite it being an exception rather than the rule.
We have several forms of tricho terschekii at our garden in southern Texas. There is a low altitude form and higher altitude form with same flowers but different stem appearance
Interesting. That doesn’t surprise me too much, since you can see variance in domestically produced plants too, so with a wide geographical range the same could be expected for wild ones.
Thanks to everyone – Great information. I moved to Prescott AZ Summer of 2020, our home is at 5600’ . Planted 2 Argentine Saguaro’s one from a 24” box / other a 15 gallon. The 24” box had several towers & threw several nice flowers Hune 2021. The other has not yet flowered but has started a nice ‘Arm’ in the last 6 months
Prescott is really pushing the limits of this species’ cold resistance, and I would caution you to consider protecting it during the occasional excessive cold snap. This might not occur every year, but I think that long-duration temps below 15F (and certainly below 10F) could prove to be too much for them if they last for more than a few hours, or for multiple nights, especially if daytime temps don’t reach above freezing at all, or only do so for a few hours in the low to mid 30s F.
Just be cautious under such conditions, and remember that once a cactus freezes severely, the damage is permanent and irreversible, which is why you want to prevent it from happening in the first place. Under the most extreme weather events your plants will benefit from protective insulation measures (and maybe even supplemental heating, e.g. via strings of Christmas lights wrapping the trunk under the covers) to prevent the frostbite. I like to remind myself that I can grow many plants 360 nights a year, and it the handful of 5 or 10 times that are going to cause all the problems. So pay attention and mitigate against those few nights per year to enjoy them the rest of the time trouble-free.
Cactus gets covered with sheets diring winter
I would like to post the picture is there any way to do that here
I grow Trichocereus terschekii and huasca here in upstate Sc , no protection. Survived 4F with no damage. Planted near house foundation on south side.
Wow, that’s quite a bit colder (and wetter) a climate than I would have thought likely, even for these. Thanks for the report.
Fred, would love to see some pictures, I live in Prescott AZ, have 2 but they get covered each Winter
Harley0711@yahoo.com
Thank you Jan for all your information
Update, Feb 2024, when I first pposted here June 2022, I ‘Thought’ I had 2 Terscheckii, learned the Nursery sold me a Hybred of Unknow?? The Other is a True Terschecki & doinging very well. It is now in its 4th Winter here. About 5’ & 2 very nice Arms & THICK😉 each winter I have built a ‘Box’ around it and stapled asheets to give it some protection. Temps have dipped to 17F but not for long & most days are Sunny
Would post pictures if I could
I don’t think that posting pictures is possible in comments with my blog server. Would be good to see them however, so if you want to email a few to me at jan @ DF Ranch com I can get them that way. Your plants sound very nice.