Genus of about three species of cactus, originating from Mexico, with erect stem, which can reach, in nature, even four meters high. The stem is green-blue, covered with bloom and grows quite quickly, with little branching. In summer it produces few white flowers, near the areolas, followed by edible fruits, with a taste similar to blueberry (hence the name), called in Mexico garambullos. It has 5-6 ribs, on which are present woolly areoles, with five to seven radial spines, red-green, and a black central spine.
Display and Watering
Exposure: the Myrtillocactus likes very bright locations, possibly in direct sunlight.
Watering: not abundant, waiting for the soil to dry between one watering and another; completely stop the administration of water during the winter.
Sandy and very well drained. To allow good growth of the plant it is advisable to repot it every one or two years, or at least when the roots completely fill the pot.
Sow in containers filled with cactus compost, sprinkling water on the ground to keep it moist; keep the sowing containers in a warm and moist place until the seedlings appear. Transplant the small cacti as soon as they can be handled, if left to grow too much in the seed container they rot easily. Cuttings can be made in mid-summer, leaving the wound to dry for a couple of days, before placing the cuttings in a mixture of potting soil and sand in equal parts.
Blueberry cactus - Myrtillocactus geometrizans: Pests and diseases and Varieties
Pests and diseases: if it receives excessive amounts of water, or the soil is not light and drained enough, it can suffer from root rot; sometimes aphids and scale insects can cause a slowdown in plant growth.
Variety: There is a particular variety called M. Geometrizans cristata, smaller than the other species; the other varieties are M. schenckii, M. chichipe and M. cochal.