Adromischus marianiae aka Mariana's Adromischus

Adromischus marianiae is considered a challenging plant to grow, even for experienced succulent enthusiasts. It is notoriously prone to rotting from either overwatering or from dried inflorescences left on the plant over winter. The species requires precise watering, excellent drainage, and good air circulation to thrive. While rewarding for collectors who can meet its needs, beginners should consider starting with easier succulents.

Adromischus marianiae is a compact, slow-growing succulent that typically reaches 10-15 cm (4-6 inches) in height and spreads to form small clusters. The leaves vary considerably across different forms, ranging from 2-12 cm long and 4-25 mm wide. The flowering spike can extend 10-35 cm above the plant when blooming. This is a relatively fast-growing species compared to other Adromischus, though still slower than many common succulents.

Adromischus marianiae thrives at temperatures between 15-30°C (59-86°F). It cannot tolerate temperatures below 5°C (41°F) for extended periods, though with perfect drainage and completely dry conditions, it may survive brief dips to -7°C (19°F). In cold climates, bring the plant indoors before frost. Avoid placing it near cold windows in winter or in excessively hot, humid conditions in summer.

In spring and summer, water when the soil is completely dry and fertilize monthly with diluted liquid fertilizer. This is the active growing period. In fall, reduce watering as temperatures cool and remove any spent flower spikes before winter arrives. During winter, keep the plant nearly dry with only occasional light watering to prevent shriveling. Keep water off the foliage in winter to prevent rot. Never fertilize during the dormant winter months.

Yes, Adromischus marianiae produces slender flowering spikes from late summer into fall. The inflorescence grows 10-35 cm tall with small tubular flowers along the stalk. Each flower is about 1-1.2 cm long, pale green at the base with pink-tinged tips and five petals that curl back to reveal their pink coloration. The waxy coating on the flower stalk gives it a whitewashed appearance. Remove spent flower spikes before winter to prevent rot.

Adromischus marianiae includes four recognized varieties: var. marianiae (the typical form with grey-green spotted leaves from the Cederberg foothills), var. hallii (broadest, thickest leaves, grey-green or red-spotted, from the South African/Namibian border), var. immaculatus (cylindrical leaves with variable texture, from South Namaqualand), and var. kubusensis (variable grey-green leaves from the Richtersveld mountains). The popular form 'herrei' with extremely rough, raisin-like leaves is now classified under var. immaculatus, though collectors still use the older name.

Propagate Adromischus marianiae from leaf cuttings by gently twisting off a healthy, plump leaf ensuring the base comes off intact. Let the leaf callous over for 1-2 days in a shaded spot. Place the leaf at a slight angle with the base just touching moist, well-draining soil. Keep in bright indirect light (not direct sun) at around 24-27°C (75-80°F). The leaf will root in a few weeks, but new plantlets emerge slowly—patience is essential. Stem cuttings and division are also possible.

Mealybugs and scale insects are the main pests affecting Adromischus marianiae. Vine weevils may also attack the roots. Use a systemic insecticide for prevention or treat infestations with rubbing alcohol on a cotton swab. The biggest threat is root and stem rot caused by overwatering or poor drainage. Fungicides have limited effectiveness against rot, so prevention through proper watering and excellent drainage is essential. Good air circulation also helps prevent fungal problems.

Repot Adromischus marianiae every 2-3 years in spring, using a small pot with excellent drainage holes. Choose a container only slightly larger than the current one, as this species prefers to be slightly pot-bound. Use a mineral-rich, porous cactus/succulent mix with added perlite or coarse sand. Handle the plant carefully as the leaves detach easily. Allow the roots to dry for a day or two after repotting before watering to prevent rot.

Adromischus marianiae can grow outdoors year-round only in USDA zones 10a-11b (minimum 30°F/-1°C). In these warm, dry climates, plant it in a protected spot with morning sun and afternoon shade, in extremely well-draining soil or a raised bed. In cooler climates, grow in containers that can be brought indoors before frost. The plant cannot tolerate wet winters or high humidity, making it unsuitable for outdoor cultivation in most temperate regions.

Mariana's Adromischus’s native range is Southern Africa.

Mariana's Adromischus does best in dry soil and should only be watered sparingly.

The Mariana's Adromischus is delicate when it comes to soil that is too damp, therefore, it is crucial to select a potting soil that has efficient drainage and doesn't hold an excessive amount of moisture. An ideal soil should consist of a substantial amount of perlite or vermiculite for proper drainage and some organic matter for nutrition. Mixing a few handfuls of perlite with commercially available cactus soil should produce the desired result.

Mariana's Adromischus requires abundant, bright and direct light. Placing it less than one foot from a window is the best way to make sure the plant receives enough light to survive and thrive. Depending on your region, however, the current weather can affect the placement of the plant in your home. For example, in some areas the sun may be too direct and intense, so it's best to place it farther away from the window. You may also need to adjust your placement according to the season as the sunlight can change intensity over the course of the year. If you live in a region with significant temperature fluctuations, such as a desert, you may need to place the plant a bit farther away from the window to avoid extreme heat or cold. With some care and attention, your Mariana's Adromischus will be sure to bring you many years of beauty and enjoyment.

Mariana's Adromischus thrives in dry environments, but if you provide extra humidity or mist your plant, the lingering water on its leaves could create an ideal environment for certain fungal diseases.

The growth of Mariana's Adromischus is gradual and it doesn't necessitate any additional fertilizers. Replacing the soil in its pot once a year should suffice to provide the plant with sufficient nutrition. It's important to keep in mind that plants derive their energy from the sun's rays, not fertilizers.

Ploi does not possess verified information regarding the toxicity of this particular plant. In the event that you, a member of your family, or a pet ingests plant material with an unclear toxicity level, it is highly recommended to seek the advice of a medical professional.