What to Do if a Cactus Has Rotting Roots and Stems
Cacti, as highly ornamental succulent plants, often encounter issues with rotting roots and stems during their care. This not only affects the plant's appearance but may also threaten its life. Mastering scientific prevention and treatment methods can bring your cactus back to life.
Analysis of the Three Main Causes of Rotting Roots and Stems in Cacti
Invasion of Pathogenic Microorganisms
70% of cactus root rot cases are caused by soil pathogenic bacteria infections. Unsterilized garden soil may carry more than 20 pathogenic bacteria such as Fusarium and Pythium. The cross-use of propagation tools can easily spread the Tobacco Mosaic Virus; it is recommended to regularly wipe tools with 75% alcohol, and new soil should be treated with high-temperature steaming or sun exposure.
Imbalance in Water Management
Excessive watering during the winter dormancy period is the main cause of root rot. It is recommended to water thoroughly once every 30 days when using terra cotta pots, and extend to 45 days for ceramic pots. Watering in summer should avoid noon, using the immersion method to control water volume, and placing 3cm of ceramic stones at the bottom of the pot can enhance drainage.
Dysregulation of Nutrient Supply
Excessive nitrogen fertilizer can thin cell walls and reduce disease resistance by 50%. Apply a phosphorus-potassium compound fertilizer once a month during the growing season, diluted at a ratio of 1:1500. Organic fertilizer must be fully decomposed, as fresh manure can produce hydrogen sulfide that burns the roots.
Complete Guide to Preventing and Treating Rotting Roots and Stems in Cacti
Four Steps for Emergency Treatment
① Remove the pot and clean the soil: Use a brush to remove any attachments from the roots. ② Excise the lesion: Sterilize the knife with alcohol and remove the discolored tissue. ③ Antiseptic treatment: Soak in 0.1% potassium permanganate for 20 minutes. ④ Air-dry the roots: Let them dry in a well-ventilated area for 3-5 days until the wound scabs over.
Key Points for Environmental Regulation
Keep 6 hours of direct sunlight during spring and autumn, use a shading net to filter 30% of the light in summer, and maintain an environment above 12°C in winter, with air humidity controlled between 40%-50%. Apply a fungicide solution to the roots every quarter to prevent diseases.
Recommended substrate mix ratio: Akadama soil 40% +鹿沼土 20% + Volcanic rock 15% + Decomposed leaf soil 15% + Coarse river sand 10%. Adding 3% charcoal powder can enhance抗菌性, and choose a breathable red terra cotta pot that is 3cm larger in diameter than the plant.
Through systematic prevention and treatment measures, 90% of cacti with rotting roots can recover. The key is to establish a maintenance concept focused on prevention, regularly check if the base is soft, and a slowdown in the growth rate of new buds is an early warning signal. Combined with reasonable management of light, water, temperature, and fertilizer, cacti can maintain their best condition.