cacti and succulents

Cause

Fungal rot (Fusarium, Phytophthora spp.) attacks cacti when plants are stressed from overwatering, root damage during dormancy re-potting, or trauma; tissue turns mushy and decays rapidly.

Solutions

• 1. Never re-pot during dormancy (October-March) — root damage combined with slow metabolism invites fungal invasion
• 2. Cut away decaying roots, drench remaining root mass with Benlate+ActiveX fungicide
• 3. Pot in 50/50 sand/cactus compost or pure sand, keep at 20°C minimum until healthy new roots establish
• 4. Allow cut surfaces to callous 1-2 weeks before re-potting; apply Keriroot hormone rooting powder to prevent secondary rot

Cause

Cacti and succulents store fluid in swollen organs (stems, leaves, pads) enabling survival during 7.5cm annual rainfall periods and air temperatures up to 50°C, with soil temperatures reaching 60°C from solar radiation absorption.

Solutions

• 1. Water freely March/April through September during active growth, allowing soil to almost dry between waterings
• 2. Reduce water to bare minimum October through March during dormancy
• 3. Use tepid water (not cold tap water) directed at compost, not plant tissue
• 4. Water with rain water if chalk deposits are visible on plant tissue

Cause

Kalanchoe and some succulents require more darkness than daylight hours to initiate flowering; early spring sunlight scorches tissue-weakened winter plants through glass magnification.

Solutions

• 1. Acclimate plants to spring sunlight gradually to prevent scorch
• 2. Move epiphytes (hoya, epiphyllum) further from window glass into diffused light
• 3. Provide south-facing window-sill for light-hungry varieties; accept etiolation on less-illuminated plants
• 4. For kalanchoe flowering, ensure 12+ hours darkness per night to trigger bloom

Cause

Root mealy bugs (Pseudococcidae) feed on roots hidden in soil, reducing plant vigor and making specimens susceptible to soil-borne fungal diseases; root systems decay silently before symptoms appear.

Solutions

• 1. Remove plant from pot and inspect roots for white cotton-wool-like patches every 1-2 months
• 2. Isolate affected plants from collection to prevent spread
• 3. Apply Sybol spray or drench every 7-14 days for 4-6 weeks during growing season
• 4. For severe cases, trim decayed roots, drench with Benlate+ActiveX, repot in 50/50 sand/cactus compost at 20°C until new roots form

Cause

Cacti and succulents tolerate temperatures as low as 4°C (40°F) but prefer minimum 7°C (45°F); winter condensation dripping on plants causes tissue damage and fungal infection.

Solutions

• 1. Maintain winter temperatures around 10°C (50°F) with minimal watering
• 2. Ensure greenhouse ventilation prevents condensation drips from roof or shelving
• 3. Remove plants from positions where water drips regularly
• 4. Avoid placing plants directly under shelving or hanging baskets with higher water-needs