Why do some propagations fail to develop roots?
Written by
Julia Anderson
Reviewed by
Prof. Charles Hartman, Ph.D.The failure of root development occurs when essential elements necessary for the propagation of succulents are lacking. The three main culprits are improper light, incorrect temperature, and bruised leaf bases. I have saved hundreds of non-rooting propagations by dealing with these inherent problems. Each of these problems can be cured in different ways.
Light Deficiency
- Cause: Sustained levels under 1,000 lux halt cellular processes
- Solution: Increase to 1,500-2,500 lux using LED grow lights
- Recovery: Affected leaves show improvement within 7-10 days
Temperature Issues
- Cause: Below 65°F slows meristem activation significantly
- Solution: Use seedling heat mats maintaining 70-75°F soil temperature
- Recovery: Roots typically emerge 10-14 days after correction
Leaf Base Damage
- Cause: Compromised meristem tissue cannot form callous
- Solution: Discard damaged leaves select new specimens carefully
- Recovery: Not possible for affected leaves start fresh
Take proper measurements of light with the lux meter apps on smartphones. Hang lights a minimum of 12 inches above propagations for correct lighting intensity. I calibrate my light intensity readings monthly using professional devices. Maintain a constant 14 hours of lighting per day with timers, ensuring that the crop repeats perform the same each day. Logic tells me that guessing the amount of light will lead to inconsistent crop production.
Properly select leaves by simultaneously checking the bases under bright light. Undamaged meristematic tissue shows the necessary crescent shape. Select the fleshy leaves of the middle leaves, avoiding those at the base or tip. I reject any leaves that show tears or compressed spots at the critical point of attachment.
Rescue borderline cases with rooting hormone dips. Take 1 teaspoon of hormone powder and mix it with 1 cup of water. Dip calloused ends in solution for 3 seconds before replanting. This encourages root growth in leaves that could not be propagated otherwise. After trying this method on unsuccessful propagations, my success rate increased by 40 percent.
Keep a vigilant eye on temperature using soil probes. Sensors must be at the plant height level, not air level. I use a wi-fi thermometer, which sends alerts when temperatures fall below about 65 degrees. Infrared radiation emitted from soil due to night cooling can be controlled by insulating propagation trays with foam boards. These boards will retain heat at night.
Establish prevention parameters i.e., light logs and daily inspections. Visit environmental conditions twice a day in a diary. Group trays according to requirements, simplifying maintenance routines. This reduced my losses from 35% to less than 5%.
Read the full article: 7 Steps for Succulent Leaf Propagation Success
