Cotyledon (Summer Type) 🌿

📊 Botanical Profile

• Key Trait: Features fleshy, often paddle-shaped or tubular leaves that can develop vibrant red, orange, or purple margins under strong light. Many develop thick, woody stems over time.

• Habitat: Native to arid, rocky slopes and scrublands with excellent drainage.

• Note: A diverse genus; growth habit ranges from compact shrubs to small, branching trees. Caution: Some species are toxic if ingested.

☀️ Light & Temperature

• Ideal Light (Indoor): PPFD 150–400 (≈ 12–35k lux).

• Ideal Light (Acclimated Outdoor): PPFD 400–800 (≈ 30–70k lux).

• Etiolation Risk: PPFD < 120 for over 2 weeks leads to weak, stretched growth.

• Sunburn Risk: PPFD > 700 for unacclimated plants, especially in stagnant air.

• Optimal Range: 15–28°C for vigorous growth.

• Tolerance: Can survive brief, dry frosts near 0–5°C. Tolerates heat up to 35–38°C only with excellent ventilation.

• Summer Dormancy: Growth slows above 30°C. Provide bright light with protection from the most intense afternoon sun and ensure strong airflow.

💧 Watering & Substrate

• **Golden Rule: Soak Deeply, Then Desert-Dry. Water thoroughly only when the substrate is 100% completely dry. Always verify with a weight check or dry skewer. They are highly drought-tolerant.

• Soil Mix: Requires fast-draining, mineral-based soil. Use 70–90% inorganic grit (pumice, perlite, lava rock) with 2–6 mm particle size. Target pH 6.0–7.2.

• Potting: Breathable terracotta pots are highly recommended. Ensure large drainage holes. A top-dressing of gravel helps keep stems dry and improves stability.

🌿 Fertilization & Growth Rhythm

• Feeding: Light & Infrequent. Use a ¼-strength, low-nitrogen fertilizer only during active growth in spring and autumn. Avoid feeding in summer (dormancy) and winter.

• Growth Cycle: Main growth occurs in cooler months. Watering should be significantly reduced or stopped during the hot summer dormancy and cool winter rest.

• Maintenance: Flush the substrate once or twice a year to prevent fertilizer salt buildup, which can cause leaf tip burn.

✂️ Propagation

• Stem Cuttings (Easiest): Take cuttings, allow ends to callus for a week or more, then plant in dry, gritty mix. Wait to water until roots form.

• Leaf Cuttings: Possible for some species. Let leaves callus fully before placing on dry medium.

• Seeds: Surface-sow onto sterile, well-draining mix. Requires patience and consistent warmth (18–24°C).

⚠️ Troubleshooting

• 🎨 Dull, Green Foliage → Needs more light. Gradually increase exposure to promote compact form and vibrant stress colors.

• 📏 Leggy, Weak Stems → Severe light deficiency. Move to a much brighter location immediately.

• 💦 Soft, Wrinkled, Dropping Leaves → Overwatering. Stop all water. Check for root rot. Increase airflow and repot into dry mix if needed.

• ⚫ Black or Mushy Stems → Stem rot. Act fast. Cut well above the rot with a sterile tool. Let the cutting dry for 1-2 weeks, then re-root.

• 🌸 No Flowers → Requires maturity, a tight root zone, and exposure to cooler, drier periods to trigger blooming.

• 🪹 Cuttings Fail to Root/Rot → Usually caused by watering too soon or insufficient callusing. Ensure full callus and keep the medium dry.

• 🔥 Brown or Scorched Leaf Tips → Can be from fertilizer salt burn or sudden intense sun. Flush soil and acclimate gradually to stronger light.

• 🥬 Pale New Growth → May indicate a need for light feeding during the active growing season.

Pro Tip: Treat them mean, keep them keen. Maximum sun, gritty soil, and infrequent water produce the most stunning, sculptural forms and intense colors. 🎨