Parodia haselbergii aka Scarlet Ball Cactus

Parodia haselbergii is considered an easy-to-grow cactus, making it excellent for beginners. It is a fast-growing, easily flowering species that tolerates a range of indoor conditions. The main care consideration is avoiding overwatering, as the plant is prone to root rot if kept too wet. As long as you provide bright light, well-draining soil, and allow the soil to dry completely between waterings, this resilient cactus will thrive with minimal attention.

Parodia haselbergii is a compact, globular cactus that typically reaches 10 cm (4 inches) in height and up to 15 cm (6 inches) in diameter at maturity. It is a fast-growing species for a cactus, and seedlings can begin flowering once they reach about 5 cm in diameter, usually within 4-5 years from seed. The plant is typically solitary and does not produce offsets freely, maintaining its neat, rounded shape throughout its life.

Parodia haselbergii tolerates a range of temperatures but prefers warmth during the growing season. In winter, keep it above 5-10°C (41-50°F) and ensure it stays dry. While the plant can briefly tolerate temperatures as low as -5°C (23°F) if completely dry, prolonged cold exposure can damage or kill it. For outdoor growing, it is suitable for USDA zones 10-11. As a houseplant, normal room temperatures are ideal, but avoid placing it near cold drafts or heating vents.

Yes, Parodia haselbergii requires distinctly different care between seasons. During the active growing season (spring through summer), water regularly when the soil dries out and fertilize every 6-8 weeks with a low-nitrogen cactus fertilizer. In autumn, gradually reduce watering. During winter dormancy, keep the plant almost completely dry—only provide occasional light misting on warmer days if the plant shows signs of shriveling. Maintain temperatures above 5-10°C (41-50°F) and provide good light. This winter rest period is important for triggering blooms in late winter to early spring.

Parodia haselbergii produces stunning funnel-shaped flowers in late winter to early spring, typically blooming for an extended period of up to two months. The flowers emerge from near the crown and are bright orange to brick-red (sometimes orange-yellow), measuring about 2 cm wide. Remarkably, individual flowers can remain open for 1-3 weeks. Plants begin flowering once they reach approximately 5 cm in diameter, which usually takes 4-5 years from seed. The species is self-fertile, so even a single plant can produce viable seeds after flowering.

Two subspecies of Parodia haselbergii are recognized. The nominate subspecies (subsp. haselbergii) has silvery-white spines and orange to brick-red flowers. Subspecies graessneri features up to 60 golden-yellow radial spines and produces yellowish-green to green flowers. Notable varieties include var. albiseta with pure white spines, and the highly sought-after crested form (f. cristata). The 'Orange Flower' cultivar of subsp. graessneri produces orange blooms instead of the typical yellow-green. All forms share the same basic care requirements.

Parodia haselbergii can be grown outdoors year-round in USDA hardiness zones 10-11, where temperatures rarely drop below freezing. In these climates, plant it in a location with morning sun and afternoon shade, using extremely well-draining soil. In cooler climates, it makes an excellent container plant that can be moved outdoors during warm months and brought inside before frost. The species will not survive a hard freeze, so in zones 9 and below, it should be treated as a houseplant or moved indoors when temperatures approach freezing.

Repot Parodia haselbergii every 2-3 years, or when the plant has outgrown its container. The best time to repot is in spring at the start of the growing season. Use a pot only slightly larger than the root ball, as cacti prefer snug containers and excess soil can retain moisture and promote rot. Choose a pot with drainage holes and use a well-draining cactus mix with 70-80% mineral grit (perlite, pumice, or coarse sand). After repotting, wait about a week before watering to allow any damaged roots to heal.

Parodia haselbergii is primarily propagated from seeds, as this solitary species rarely produces offsets. Sow seeds in spring on the surface of a well-draining, sterilized cactus mix and keep them in a humid environment at 21-27°C (70-80°F). Germination typically occurs within 7-14 days. Keep seedlings in bright indirect light and gradually reduce humidity as they establish. Since the species is self-fertile, you can collect seeds from your own flowering plants. Seedlings grow relatively quickly for a cactus and may begin flowering in 4-5 years.

The most common problems affecting Parodia haselbergii are root rot from overwatering and fungal diseases in poorly ventilated conditions. The main pests to watch for are mealybugs (appearing as white cottony masses) and spider mites (causing stippling and fine webbing). Scale insects may also occasionally appear. Maintain good air circulation, avoid overwatering, and inspect plants regularly. Treat infestations with rubbing alcohol on a cotton swab for small numbers of mealybugs, or use insecticidal soap or neem oil for larger infestations. Systemic insecticides can be effective for persistent problems.

Scarlet Ball Cactus’s native range is Northern South America.

Scarlet Ball Cactus does best in dry soil and should only be watered sparingly.

To keep your Scarlet Ball Cactus healthy, it's important to use a potting soil that won't retain too much moisture. A soil that drains well and contains perlite or vermiculite for drainage and some organic matter for nutrition is ideal. Adding a few handfuls of perlite to regular cactus soil from the store is an easy way to create this type of soil mix.

Scarlet Ball Cactus thrives in bright and direct sunlight. To ensure your plant receives enough light to survive, place it less than one foot from a window. The current weather in your area may affect the placement in your home. For example, if you live in a region that has longer and more intense periods of sunlight, then you may want to place the plant farther away from the window to avoid direct sunlight and reduce the risk of sunburn. Alternatively, if you live in a region with relatively milder temperatures and less intense sunlight, then you may be able to place the plant closer to the window for increased exposure. Ultimately, the current weather in your area should be taken into consideration when determining the best placement for your Scarlet Ball Cactus.

Scarlet Ball Cactus prefers dry environments, so misting the plant to provide extra humidity and allow water to linger on the leaves can create an ideal environment for fungi that can be harmful.

The Scarlet Ball Cactus is characterized by its slow growth and doesn't need fertilization in addition to its potting soil. By renewing the soil in its pot once a year, it should have enough nutrition. Remember, plants get their energy from sunlight, not from any fertilizers.

There is no verified data on the toxicity of this plant in the records of Ploi. If any person, including yourself, a family member, or a pet, consume plant material with an uncertain toxicity level, it is advisable to seek the advice of a healthcare expert.