Grafting with Myrtillocactus geometrizans.
General Growth Parameters
Light intensity tolerance:
Daylight Hours: 8-16
Shade tolerance: Tolerates partial shade, benefits from at least a five hours of direct sun. Stems will become very thin in low light and also tend to be more prone to rot and pest infestation.
Water tolerance: Tolerates massive amounts of rain if not cold, but will rot if waterlogged for extended periods. This is, surprising as it is, one of the more water tolerant species we use and we have grown it outdoors in Taiwan which gets some of the heaviest rain on earth.
Drought tolerance: Can tolerate true dry soil for a long time. When used as a grafting stock it is not advised to let stocks dehydrate too much.
Growth speed: Myrtillocactus geometrizans is a great fast growing rootstock growing scions at a fast speed. Though slower than Hylcoereus, Selenicereus and Pereskiopsis it is up there with Harrisia and Trichocereus. For fast growth, keep above 20C.
Myrtillocactus geometrizans grafts well as a scion onto other stocks. There are some rare and valuable forms of Myrtillocactus geometrizans, such as variegated and variegated crests. It can be worthwhile grafting some of the more uncommon varieties and mutations. In general it is a very easy plant to both graft onto and be used as a scion. Follow standard flat grafting procedure found here: Grafting Cacti.
Weaknesses of Myrtillocactus geometrizans as a rootstock
* Not cold tolerant, should be kept above 3C to live and about 10-15C to grow fast.
* Slightly slower than the tropical vine cacti stocks, but much more robust and long lasting.
Grafting onto Myrtillocactus geometrizans rootstocks
Follow standard cactus grafting procedure with this stock. It is one of the easiest rootstocks to graft too so long as you are grafting onto new active growth. You may view the procedure page here: Grafting Cacti.
Here are some pointers to make grafting to Myrtillocactus geometrizans easier
* Only graft during the warm season when plant is actively growing. New growth is obvious with this species at it will be blue in colour in contrast to the previous yearís growth which will be green.
* Squeeze the tip gently and make sure it feels slightly soft, yet still firm. Dehydrated stems with ribs that bend when you cut are too dehydrated. A knife should slip through without having the stem flex with the blade.
* Donít use older growth as it will be too woody and future scion growth will be far slower.
* Keep humid but in very good air flow. This cactus has a bigger cut surface area and thus a bigger invitation to fungus spores. Rust is the most common thing witnessed on cut surfaces. To avoid it provide more fresh air and once graft heals, drier air.
* Removing all areoles will indeed help speed, but is not necessary.
Have the stocks growing in preferably 20C + temperatures for a good month to get it actively growing. When you see over 5cm of new growth you can cut into that for grafting, more is probably better. Keep well hydrated at all times before grafting, and stop watering once grafted until scion is well healed (1-2 weeks). Myrtillocactus like sunshine, so growing in good light is ideal for growing thick healthy plants. The reason many plants in nurseries in North America and Europe are thin is due to poor lighting and conditions. Myrtillocactus geometrizans easily reach 15cm diameter, often more, when given the opportunity. We usually graft to stocks around 3-8cm depending on the scion.