Topping is a cannabis training method that removes the top growth tip of a plant just above a node, which splits one main stem into two colas. Growers top during the vegetative stage, typically once the plant has four to six nodes, to build a wider canopy and even out light exposure. The cut shifts auxin away from the top shoot, so lower branches catch up and fill the space.
What does topping actually do to a cannabis plant?
Cannabis grows with apical dominance: the highest shoot receives the most auxin and takes most of the light and energy. Cutting that tip removes the dominant sink and forces the two shoots at the node below to grow as co-leaders. The result is a shorter, bushier plant with two tops where there was one.
- Doubles the number of main colas at each cut point
- Lowers overall plant height, which helps in tents and small rooms
- Creates a flatter canopy that uses grow light more evenly
- Adds a short recovery pause of roughly three to seven days
When is the right time to top a cannabis plant?
Top when the plant has at least four to six true nodes and a healthy root system, usually three to four weeks into the vegetative stage. The plant should be actively growing, with no signs of stress, pests, or nutrient burn. Photosensitive varieties handle topping at almost any point in veg, as long as you leave two to three weeks before switching to flower.
How to Top Cannabis Plants for Optimal CBD Extraction
Should you top autoflowering cannabis?
Autoflowers run on a fixed clock and have less time to recover, so topping is riskier. If you top an auto, do it once, early, at the third or fourth node, and only on a vigorous plant. Low-stress training is a safer choice for small or fast autoflowering plants.
How do you top a cannabis plant step by step?
- Sterilize scissors or a blade with alcohol and let it dry.
- Find the newest node with two small shoots emerging at the stem.
- Cut the stem about 5 mm above that node, removing the top growth tip.
- Leave the two tiny shoots at the node intact. They become your two colas.
- Keep the plant in veg with steady light, water, and mild nutrients for a week.
- Top each new branch later if you want four, eight, or more tops.
What is the difference between topping, FIMing, and LST?
- Topping removes the growth tip entirely and produces two clean colas.
- FIMing cuts part of the tip, often producing four or more shoots but with messier results.
- Low-stress training bends and ties branches without cutting, which spreads the canopy with no recovery time.
Many growers combine all three: top once or twice, then tie the new branches outward as they stretch.
How many times can you top one plant?
Most home growers top two or three times, waiting one to two weeks between cuts so the plant can rebuild. Repeated topping in a planned pattern is called mainlining or manifolding, and it can produce eight or more even colas. Stop topping at least two weeks before you flip to flower, since new cuts need time to develop.
What are the most common topping mistakes?
- Cutting below the node and losing both new shoots
- Topping a seedling before it has a real root system
- Topping during the first weeks of flower, which stalls bud development
- Using a dull or dirty blade that invites stem rot
- Feeding heavily right after the cut instead of letting the plant recover
Does topping change CBD or THC content?
Topping does not change the cannabinoid profile of a plant, because potency comes from genetics. It changes how that potency is spread across the canopy by creating more, smaller colas instead of one large top. Light reaching lower buds matters more for final quality than the number of cuts, and lab testing is the only way to confirm CBD or THC levels.
Is topping cannabis legal where you live?
Cannabis cultivation rules vary by country, state, and county, and home growing is not allowed everywhere. Check local law before you plant, top, or harvest anything. This guide covers horticultural technique only.