Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

adequate roots develop.
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This female was pruned and bent to keep a low profile and open up the center of the plant.
    Mother plants are much larger, grow longer, and can require containers up to 30 gallons (115 L) in size. However, mother plants grow quite well in five or ten-gallon (19-38 L) hydroponic containers for a year or longer. If you plan to keep a mother plant for more than a few months, grow it hydroponically in its own container for best results.

Pruning and Bending
    Pruning and bending a plant redirects growth hormones. Pruning affects the plant more drastically than bending. Selective pruning and bending allow us to manipulate auxin hormone levels in branch and flower tips. Removing or bending a branch or branch tip causes hormonal balances to shift. Cutting the meristem (top growth tip) of a cannabis plant will diffuse auxins and cause greater concentrations in lower branch tips. Bending a growing tip changes hormone concentrations less than pruning.
Pruning
    Always use clean instruments when pruning. A straight razor, single-edge razor blade, a sharp pair of pruners, or a pair of scissors all work well. Sanitize clippers and blades between cuts by dipping in rubbing alcohol. Use indoor pruners only in the indoor garden. Pruners used outdoors have everything from spider mites to fungus spores on them. If outdoor clippers must be used, dip in rubbing alcohol to sterilize before making cuts.
    After pruning, the open wound invites diseases and pests. Wash your hands and tools before and after pruning. Make cuts at a 45-degree angle to discourage moisture from sitting on wounds.
    Avoid pruning up to a month before inducing flowering. Since pruning diffuses floral hormones, flowering is retarded. If heavily pruned shortly before flowering, peak maturation is delayed for a week or longer. It takes a month or longer for hormones to build up to pre-pruning concentrations.
    Leave leaves alone! Removal of healthy leaves hacks up a healthy plant. Removing large fan or shade leaves DOES NOT make plants more productive even though this practice supplies more light to small leaves and growing tips. Plants need all their leaves to produce the maximum amount of chlorophyll and food. Removing leaves slows chlorophyll production, stresses the plant, and stunts its growth. Stress is a growth inhibitor. Remove only dead leaves or leaves that are more than 50 percent damaged.
     
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There are a few basic techniques to pruning marijuana, including:

Prune off the top of the plant below the first set or two of branches to drive hormones to lower branches. Pruning off more of the main stem will increase the effect.

Prune off the tip of plants to diffuse hormones and make lower branches grow more.

Prune the tips of all branches except the main tip to make plants tall.

Remove lower branches that do not receive light. Plants will direct energy into buds.
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Pruning off all lower branches makes inspecting irrigation fittings easy and diminishes problems associated with weak growth.

No pruning was done in this room. Buds were so big in this room that plants were staked with bamboo sticks.
    Remove spindly branches and growth that is not collecting light energy, including dead and dying leaves. Pruning lower branches concentrates auxins in upper branches which forces growth upwards. Cut lower branches off cleanly at the stem so no stub is left to rot and attract pests and diseases. If you must harvest a little smoke prematurely, removing a few lower branches will diminish the harvest the least.
    Pruning out spindly branches and growth inside plants opens up the interior and provides more and better air circulation. It also allows light to reach deeper inside plants.

Pruned plants often seal themselves, but problems can still arise when there is an appealing opening for pests.
    Not pruning has several advantages. Floral hormones are allowed to concentrate in tips of branches causing buds to grow stronger and denser. Unpruned plants are crammed into a small area. Crowded plants have less space to bush out laterally and tend to grow more upright. Clones are set into the flowering room after 1-30 days in the vegetativeroom. All the little clones are packed tightly together in three-gallon pots. Each one of the plants is taking up the minimum amount of space for the minimum amount of time to produce the maximum amount of marijuana. Light is much more intense, and the entire plant grows flower tops with few fan