Pruning and training are common usages. Tomato growers pinch out side shoots, giant pumpkin aficionados remove all but one flower. Cannabis growers too have their own preferences for optimising their marijuana bud potential.
General marijuana pruning and training tips:
- always use secateurs or sharp knife to avoid bruising
- when using ties, leave them loose enough to allow for plant growth but tight enough to support the stem.
Stem Tip Removal (meristem pruning)
Object: Shorter, bushier plant
Technique: Pinching out the main stem tip encourages those growing tips below the removal point to branch out. Use secateurs or sharp knife to avoid bruising
Timing: When the main stem has reached optimum height (20-30cm).
Disadvantages: Pruning the main stem late in plant development inhibits flowering because it removes the meristemic tissues that sense light changes. Therefore unless there is a specific reason for delaying flowering, avoid in mature plants. Often combined with LST technique(see below)
Useful for: Outdoor growing – makes a more discreet plant
Object: Limits height of plants without pruning main stem
Technique: Similar to growing grapes along a trellis. Insert posts into ground 1m – 3m apart, with
horizontal support wires at 30cm intervals. Marijuana seedlings are planted between the posts and as they grow are gently bent and attached to the supports with garden twine, training the limbs to grow horizontally. When flowers begin, these are allowed to grow upwards for maxium light.
Disadvantages: Need to have secure grow area – puts a number of plants in one place
Useful for: Outdoor growing
Screen of green: SCROG
Object: Similar to a “Sea of Green” effect using training instead of multiple small plants. Planting
Technique: When plants are 15cm tall, pinch out to encourage short bushy growth (see meristem pruning above). A slightly slanted or horizontal framework of chicken wire is placed over the plants 30-60cm above growing medium. As plants grow during vegetative stage, they are trained horizontally underneath the framework and held in place with twine. As the marijauana plants are put into flower, the floral clusters are encouraged to grow upwards through the netting
Disadvantages: It is important to be observant. If the plants are left without training, the area becomes out of control and messy. Possibility of damage to the plant when bending stems – it can be fiddly.
Useful for: Indoor grows with limited vertical space and lighting with limited penetration. Works best used with marijuana clones for uniformity of mature plant size and flowering time.
Low Stress Training Technique (LST)
Object: Increases light penetration to a bushy plant
Technique: Place a framework around the plant and gently bend stems outwards and tie to frame (see photo). An alternative method is to weight the outer stems by tying weighted strings (ie with rocks) to pull the branches down and outwards.
Disadvantages: The weighted strings method makes the plant vulnerable in strong winds as the plant loses flexibility. This can lead to main stem splits
Useful for: Any bushy plant, indoor or outdoors
This marijuana pruning technique removes the often unproductive lower shoots which never receive much light or develop anything but tiny buds, thus allowing the plant to concentrate its energy on the major flowers. Shock is minimised by removing the whole stem.
Common amoung growers in some areas of the world, for example Spain, where the same practice is used for tomato plants, this is the removal of large shade leaves during the flowering stage. The theory is that these leaves draw energy away from the buds and may indeed accelerate flowering maturation. However, tests suggests that these large leaves photosynthesize the energy needed for good buds, and even as the plant matures and the leaves turn yellow, it is better to let these gradually reabsorb the energy rather than shock the marijuana plant by pruning them. Leaf removal may even prompt sex change.
Supercropping: what is it and how does it work?
Supercropping means combining a number of pruning and training techniques to get the best out of your marijuana plant. It can include the techniques listed above, but also less common practices such as crimping and knuckling. We’ve coined the phrase “extreme stress training” to describe some of these, and you can read all about them here