Monday, July 30, 2007

Spruce Cone Cholla Thrives On Neglect

Tephrocactus articulatus var. diadematus 'inermis'
Spruce Cone Cholla

Last year as I was leaving a cactus nursery, I saw a segment of Spruce Cone Cholla (Tephrocactus articulatus var. diadematus 'inermis') lying on the ground in the parking lot. It appeared to have been there for quite some time, as it was quite dehydrated and wrinkly. Obviously, it had come off someone’s purchase during transport to his or her vehicle. It was surprising that it hadn’t been flattened in the busy parking lot.

Since this form of T. articulatus doesn’t have any spines, (“inermis” derives from the Latin adjective meaning unarmed or spineless) I picked up the segment with my bare hands and took it home. Segments of T. articulatus easily separate from the main cactus and readily root, so I placed the segment in full sun, barely touching the soil under the landscape granite. Within two weeks, it had formed a bud and flowered. Although the segment sort of blends in with the gravel in the photo, it is easy to see that it was still in its dehydrated state. Dehydration does not stop flowering.

Since then, this Spruce Cone Cholla has grown to one foot tall with nine segments. It is nice, plump, and thriving. I watered this cactus sparingly for a couple of months until it had rooted, and then stopped completely. It needs no supplemental water, other than that from an occasional rain.

There are five species in the genus Tephrocactus, sometimes classified under the Opuntia genus. None of the five is frost sensitive. The T. articulatus species has several varieties in addition to the one described here. I wrote about one of those varieties in another post.


kate said...

I wish I made finds like this in the garden centre parking lot. The flower is really pretty.

So if it isn't frost sensitive, could I grow it here?

No Rain said...

Hi Kate,
This cactus will do ok in Sunset Zones 8-9,11-24: USDA Zone 9-11, so I think you are way too far north. The minimum AVERAGE temperature it will take is 50 degrees F. The reason it takes frost here is although we have occasional frosts and even freezes, our averages are always above 50 degrees F. You could try it in the house, but you are so far north you would have to add some strong artificial light for many hours a day. Many folks in northern climates grow cactus in the house, but it's a real commitment!