Pereskiopsis aquosa is an unusual cactus native to Mexico that does not fit the typical desert image. Unlike most cacti, this species retains persistent, flat, fleshy leaves and has a shrubby, pencil-thick growth habit. It belongs to the Opuntioideae subfamily, characterized by barbed bristles called glochids alongside its spines. Its vigorous growth rate and readily available vascular tissue make it highly sought after by cactus enthusiasts. This leafy cactus functions primarily as a fast-acting, temporary rootstock, particularly for micro-grafting delicate or slow-growing cactus seedlings.
Essential Care for Healthy Growth
Cultivating Pereskiopsis aquosa requires an approach that differs significantly from caring for typical desert cacti. This species is a heavy feeder, necessitating a potting medium with a high organic component, often up to 75% organic material. While it needs fast drainage to prevent root rot, incorporating materials like perlite and pumice provides aeration and structure.
The plant thrives in bright, filtered light, mimicking its natural under-canopy habitat. Direct, intense midday sun can scorch the foliage and thin stems, so caution is advised in hotter climates. Since P. aquosa is not cold-hardy, it prefers consistent warmth and must be protected from temperatures approaching freezing.
Due to its leaves and rapid growth, Pereskiopsis aquosa requires more water than most cacti, especially during its active growing season. The soil should be kept consistently moist but never waterlogged, demanding a weekly watering schedule rather than the infrequent deep soaks typical for desert plants. Maintaining higher ambient humidity is beneficial and supports the plant’s lush growth.
Expanding Your Stock Through Propagation
The most efficient method for multiplying Pereskiopsis aquosa is through stem cuttings, as the plant rarely sets seed in cultivation. To prepare a cutting, select a healthy, non-woody stem and use a sterilized blade to make a clean cut. Remove the lower leaves and any surrounding glochids, leaving about a half-inch of bare stem at the base.
While some growers allow a brief callousing period, the high water content of Pereskiopsis often allows the cutting to be planted immediately. The prepared segment should be placed into a moist, well-draining soil mix, ensuring the base is covered. Providing bottom heat and high humidity will accelerate the rooting process, which typically occurs within seven to ten days.
Cuttings can also be rooted successfully in water, offering visual confirmation of root development before transplanting them into a solid medium. Once roots emerge, the new plants should be potted up and allowed to establish for several weeks before being used as grafting stock. This ensures the root system is strong enough to support the rapid growth of a grafted scion.
Step-by-Step Guide to Grafting
The primary use of Pereskiopsis aquosa is as a fast-acting rootstock due to its exceptionally rapid growth rate and strong vascular connection. Before beginning the process, the rootstock plant should not be watered for four to five days to prevent excessive sap pressure from pushing the delicate scion off the fresh cut. All tools, especially the razor blade or scalpel, must be sterilized with isopropyl alcohol to prevent the introduction of pathogens.
The grafting process begins by making a single, flat, horizontal cut across the top of the Pereskiopsis stem, removing the growing tip. This exposes the vascular ring, which appears as a small, central dot responsible for nutrient and water transport. The scion, typically a small cactus seedling, is then sliced horizontally across its body with the same sterile tool. The scion’s cut surface should match the diameter of the rootstock as closely as possible.
The scion is immediately placed atop the freshly cut Pereskiopsis stock, aligning the two vascular bundles to ensure contact. Because the vascular rings on tiny seedlings are difficult to see, placing the scion slightly off-center often guarantees an overlap between the two tissues. A gentle push helps to seat the scion and expel any air bubbles that might prevent a successful union.
Unlike grafts on larger rootstock, external fasteners like rubber bands are usually unnecessary to secure the tiny scion. The freshly completed graft must be immediately moved into a high-humidity environment, such as a sealed plastic container or under a humidity dome, for about seven days. This temporary high humidity prevents the exposed cut surface of the Pereskiopsis from shriveling, which is a common cause of graft failure.
After the initial week, the humidity dome can be slowly removed, and the graft should be placed in bright, indirect light to encourage growth. Monitor the stock for any lateral offshoots, or pups, that emerge from the areoles below the graft union. These must be removed promptly to ensure all the plant’s energy is directed toward feeding the newly attached scion.