Description
The typical Echinocactus grusonii “albispinus” (white spined form) is a strong bright white spined mutantant of the well known “Golden barrel cactus” that - except for the spines - it is identical in shape and size to the standard species. The standard form is very popular and widely grown, while the beautiful white spined crested variant is still rare in cactus collection. This crest can also get very big making a spectacular specimen.
Habit: Echinocactus grusonii is a solitary globe-shaped cactus that became elongated (barrel-shaped) in maturity, up to 90 cm (180 cm) in height and spread. It sometime offset with advanced age and a few multiples occur even at small sizes.
Stem: Pale green and heavily ribbed with numerous areoles sprouting radial, yellow spines (bright white in the var. albispinus).
Flowers: Flower are diurnal, vivid yellow (4-5 cm wide) and form a circular ring at the top of the plant, but are not very visible being small in relation with the size of the barrel, and lost into the creamy coloured wool at the plant apex.
Blooming season: Flowers are produced from end of spring to summer only on larger mature specimens receiving enough full sun.
Remarks: The juvenile Echinocactus look quite different from the mature specimens. In fact as the other Echinocactus and Ferocactus seedlings, the rib structure is not yet apparent, and they have pronounced tubercles making them look superficially like Mammillarias.
Origin and Habitat
Garden origin (Nursery produced cultivar)
Cultivation and Propagation
It is not too difficult in a greenhouse, although grows quite slowly. It is usually seen as a grafted plant but can grow on its own roots too.
Soil: Use a mineral well permeable soil with little organic matter (peat, humus).
Exposure: They need a good amount of light shade to full sun this help to keep the plants healthy, although slow growth.
Watering: Water sparingly from March till October (weekly during summertime, if the weather is sunny enough), with a little fertilizer added. Less or no water during cold winter months, or when night temperatures remain below 10° to prevent root loss. It is sensitive to overwatering (rot prone).
Fertilization: Feeding may not be necessary at all if the compost is fresh then, feed in summer only if the plant hasn’t been repotted recently. Do not feed the plants from September onwards as this can cause lush growth which can be fatal during the darker cold months.
Hardiness: Keep perfectly dry in winter at temperatures from 5 to 15 degrees centigrade. (but it is relatively cold resistant and hardy to -5° C, or possibly colder for short periods) In the rest period no high atmospheric humidity!! (Temperature Zone: USDA 9-11)
Crested growth: Unlike ‘monstrose’ varieties of plants, where the variation from normal growth is due to genetic mutation, crested growth can occur on normal plants. Sometimes it’s due to variances in light intensity, or damage, but generally the causes are unknown. A crested plant may have some areas growing normally, and a cresting plant that looks like a brain, may revert to normal growth for no apparent reason. If you have any of the crested part left you need to remove the normal growth and leave the crested part behind this will need to be done regularly.
Propagation: Grafting or cuttings. Plants are usually grafted onto column-shaped cacti but proved to be able to produce their own roots if degrafted. Cuttings will take root in a minimum temperature of 20° C (but better in hot weather). Cuttings of healthy shoots can be taken in the spring and summer. Cut the stem with a sharp, sterile knife, leave the cutting in a warm, dry place for a week or weeks (depending on how thick the cutting is) until a callus forms over the wound. Once the callus forms, the cutting may be inserted in a container filled with firmed cactus potting mix topped with a surface layer of coarse grit. They should be placed in the coarse grit only; this prevents the cut end from becoming too wet and allows the roots to penetrate the rich compost underneath. The cuttings should root in 2 to 6 weeks. Large crested piece must be placed on the soil surface without burying the plant base down in the soil.
