Parodia graessneri
| Light | Bright light with some protection from the harshest summer sun |
|---|---|
| Water | Regularly in the growing season, allowing the soil to dry between waterings; keep dry and cool in winter |
| Soil | Fast-draining mineral mix with a little extra organic matter (see Soil and potting mix) |
| Temperature | Keep above freezing; a cool, dry winter rest suits it best |
| Propagation | Seed, and offsets from older clustering plants |
| Toxicity | Non-toxic to cats and dogs |
Parodia graessneri is a small, globular South American cactus clothed in fine, golden-yellow bristly spines, best known among growers for flowering unusually early in the year. While most of its relatives bloom in spring and summer, P. graessneri pushes out its greenish-yellow flowers in late winter to early spring, making it a welcome splash of colour when little else in the collection is awake. It belongs to the genus Parodia, and was long known under the older names Notocactus graessneri and Brasilicactus graessneri.
Description
Parodia graessneri forms a solitary, flattened-globular body that becomes shortly columnar with age, typically reaching around 6–10 cm across. The green stem is divided into numerous low, spiralling ribs studded with closely set areoles, and the whole plant is densely covered in soft, hair-fine bristly spines of a bright golden-yellow. The spines curve and interlace over the crown, giving mature plants a warm, glowing appearance in good light.
The flowers are the species' calling card. They are relatively small, funnel-shaped and an unusual greenish- to lemon-yellow, opening from the woolly crown in late winter to early spring — notably early for a cactus. Older plants may cluster from the base, forming small groups over time.
Distribution and habitat
Parodia graessneri is native to southern Brazil, where it grows in the state of Rio Grande do Sul. In habitat it is typically found on rocky outcrops and among grasses and low vegetation, rooting into gritty pockets of mineral soil with sharp drainage. This is a subtropical, summer-rainfall region rather than a true desert, and the plants receive reasonably regular moisture through the growing season followed by a cooler, drier winter — a rhythm worth remembering when growing them.
Cultivation
Parodia graessneri is a rewarding and reasonably forgiving cactus for the keen hobbyist. Grow it in a free-draining, mostly mineral mix that holds a little more moisture and organic matter than you would give a desert species, and place it in bright light with some protection from the fiercest midsummer sun, which can scorch the fine spination. During the growing season it appreciates more regular watering than many cacti — water thoroughly, then let the mix dry before the next drink.
The key to good flowering is a proper winter rest: keep the plant cool and dry through the coldest months, which both encourages those early blooms and guards against rot. Protect it from frost. Being a summer-rainfall plant from a relatively humid habitat, it dislikes prolonged baking and drought more than most, so do not let it stay completely parched for months on end during active growth. See Repotting for general technique.
Propagation
The species is usually raised from seed, which germinates readily on a warm, humid, mineral surface — the standard method for the genus. Older plants that have formed clusters can also be divided, with rooted offsets separated and potted up individually. Grafting is sometimes used to speed up slow seedlings, though it is less necessary here than for some fussier cacti.
Common problems
- Rot — the most common cause of loss, almost always from overwatering, poor drainage, or moisture during the cold winter rest; the body softens and discolours from the base.
- Scorch — the fine golden spines and the skin beneath can be damaged by sudden exposure to intense direct sun; acclimatise plants gradually in spring.
- Pests — mealybugs (white fluff nestled among the spines and in the areoles) and red spider mites (fine webbing and a dull, bronzed look) are the usual offenders. See Pests and diseases.
See also
- Parodia — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting