These are the mean spined columnars from Chile. Trichocereus or Leucostele if you please. We love them for those spines, their notchy epidermis and old branched out stands in the Atacama desert. Many of the Trichocereus collectors are obviously attracted to this plant, but you can also find the Atacama fanboi’s staring at these columnars. T. chiloensis, fulvilanus, skottsbergii, nigripilis and the like are some of our favorites in this line of cactus.
These ornamental plants are grown outdoors in full Southern California sun, no shadecloth, no greenhouse.. They are healthy but some have some blemishes and marks maybe evidence of old pests even. We do our best to keep them healthy. I’ve recently knocked it down with an insecticide and fungicide. Plants sent unpotted or bare root when dry.
I use hormodin3 rooting hormone and I like to dry for a week or two on their side exposed to air. When calloused I root them in pure coco coir or potting media. I stand them up and keep them dry. Warmth at the base with a heat mat in winter helps or warm direct sun in the morning for 2-3 hours. I then taper in more sun around lunch and then all day if you can without burning it. Small sips of water as the medium dries to tease the roots out. This can be 2 weeks to 2 months. When roots arrive then I pot them in soil. And let them get some water. Or you can do all of this in the same pot of soil if you like.
T5 full spectrum bulbs or a good LED vipar spiderfarm hlg is good. You can dive into ppfd and lux etc
Have heat mats that have a thermocouple set to 75* in the soil. You don’t want the soil to get too hot so it must be regulated.
Use clean new soil. Pasteurize in the microwave if you so choose. Start your seed with a soak of hydrogen peroxide as that helps slightly soften the kernel. Some people like to go a bit stronger with fungicides to start with too.
I Feed often . Kelp or a good liquid nutrient. They are fairly hungry plants even at this size. Mycorrhizae when you can. Beneficial microbes are great too.
Humidity domes for 2-3 months is what I use to get them to germinate and grow to the size where they can acclimate to no domes. Some people use takeaway containers as they can hold the moisture in indefinitely without having to refeed or water. Most important is find what works for you!
