Mother plant maintenance: the short answer
Keep a cannabis mother plant in the vegetative stage under 18 hours of light and 6 hours of dark. Take cuttings from the lower and middle branches. Remove 20 to 30 percent of the foliage in one session. Replace the mother every 6 to 12 months. A plant kept past that window grows woody stems and passes less vigor to clones.
cloning cannabis from mother plants
Light schedule and intensity
18/6 is the standard cycle for stock plants. A dark period shorter than 12 hours holds the plant in veg. Dropping to 12/12 flips the mother into flower, and the plant stops producing usable cuts for 8 to 10 weeks. Target 400 to 600 PPFD at the canopy. Levels above 700 PPFD stress a plant that never gets a rest cycle.
Water, nutrients, and pH
Mothers need less nitrogen than flowering plants but more calcium than clones. Run EC at 1.2 to 1.6 in coco or hydro. Keep pH at 6.0 to 6.8 in soil and 5.5 to 6.5 in coco, rockwool, or deep water culture. Let the top 1 to 2 inches of media dry before the next watering. Wet media for weeks at a time invites fungus gnats and root rot.
Temperature and humidity
Hold the room at 68 to 77 F. Relative humidity of 60 to 70 percent fits veg growth. Above 80 F with humidity over 70 percent, powdery mildew and botrytis move in. Add airflow at the canopy. Do not aim a fan at one leaf for days. That leaf dries out and turns crisp.
Pruning and cut schedule
Take cuts 4 to 6 inches long with 3 to 4 nodes. Strip the bottom node. Cuts root in 7 to 14 days under a dome at 75 F. Keep 4 to 8 main branches per mother. Take no more than 30 percent of the foliage in one pass. Space passes 2 to 3 weeks apart. Pinch the top two nodes on a young mother to force side branching. More branches means more cut sites at each session.
Roots and containers
Use a 3 to 5 gallon pot. A root-bound mother stalls, drops lower leaves, and takes longer to push new growth. Repot into fresh media every 3 to 6 months. If the pot size is fixed, root prune about 25 percent of the root mass, then return the plant to the same container. Fresh media also resets salt buildup from months of feeding.
Pests and quarantine
Spider mites, thrips, and fungus gnats are the three common problems on stock plants. A mother stays in veg, so the pest cycle never breaks. Check leaf undersides every 3 to 4 days with a 10x loupe. Quarantine new clones for 14 days in a separate room. One mite on a mother becomes mites on every clone from that mother.
Replace or rejuvenate
Label each mother with the strain, the date it rooted, and the number of cuts taken. Start a new mother from a cutting at month 6 to 12. Keep two mothers per strain so a single loss does not end the line. Clones from a first-generation mother root faster than clones from a mother that has run for 2 years.
Common mistakes
- Running 12/12 to save power. That flips the mother to flower.
- Feeding bloom nutrients with high phosphorus. Mothers need veg ratios.
- Letting the media dry to the point of wilt. Wilting slows new growth for a week.
- Taking cuts from a mother with a pest problem. The clone room gets the pest.
- Skipping labels. A tray of unmarked clones has no strain record.
- Keeping one mother for a whole strain. One root problem ends the genetics.