Vegetative stage: training, topping, and the time to be aggressive

Vegetative stage is when the plant is growing leaves, branches, and roots, but no flowers. For photoperiod strains, you control veg length by keeping the lights at 18 hours on, 6 off (or 20/4 for more aggressive growth). When you flip the schedule to 12/12, the plant senses long nights and starts flowering. You decide when that happens.

Autoflowers do not work this way. They flower on age alone, typically around week 4 to 5 from seed. The training window for autos is short, maybe 2 to 3 weeks, before the plant commits to flower whether you like it or not. Aggressive training on an auto can stunt it badly.

Typical photoperiod veg time indoor: 4 to 8 weeks. Longer veg = bigger plant = more yield, but also more space and electricity. Most home growers settle around 5 to 6 weeks.

Once your plant has 4 to 5 nodes, you can cut the top off cleanly. The plant responds by promoting the two side branches at that node into new main stems. Instead of one giant cola at the top, you now have two. Top those two later and you have four.

Most home growers top once or twice per plant. Aggressive growers do mainlining: a series of 3 to 5 topping rounds that produces 8 or 16 evenly-spaced colas with a symmetric, manifold-like shape. Mainlining adds 2 to 3 weeks to veg time but produces some of the cleanest, most uniform plants you will see.

FIM (an abbreviation that originates from a swear) is a partial top where you only remove the top growth tip, leaving the surrounding leaves. The plant can respond by producing 3 or 4 new tops instead of the cleaner 2 from a full top. Results are inconsistent. Most growers use full topping for predictability and only experiment with FIM if they like surprises.

Bend the branches and tie them down sideways with soft plant wire or hemp twine. Never use nylon string. It cuts into the stem as it thickens. The point: spread the plant out flat so light hits more bud sites evenly.

LST can be applied throughout veg and into the first 1 to 2 weeks of flower. Combined with topping, it produces a wide, even canopy where 8 to 16 colas share the light instead of a single dominant top.

A horizontal mesh screen positioned 8 to 12 inches above the soil. As branches grow up through the screen, you tuck them sideways under it. The result is a brutally flat canopy with 15 to 30 evenly-distributed bud sites.

SCROG yields per plant are excellent but setup is more involved. A 4x4 tent typically runs one plant scrogged or two plants topped and LST'd. The trade-off is plant count vs per-plant maintenance.

Cutting leaves selectively to improve light penetration. Two main approaches. 'Lollipopping' removes leaves and small branches from the bottom third of the plant so all the energy goes to the top canopy. 'Schwazzing' is a heavier defoliation done 1 to 2 times during flower, removing up to half the fan leaves in a single session.

Schwazzing is controversial. Some growers report bigger denser buds. Others report stress, slower growth, and reduced yields. The honest answer is it depends on the strain, the environment, and the grower's experience. New growers should not schwazz on their first or second grow.

Universal rule: never remove more than about 25% of the leaves in one session, and never schwazz in the last 3 weeks before harvest.

Stop topping and major structural training at least 2 weeks before the 12/12 flip. The plant needs time to recover and stabilize. LST can continue into the first 1 to 2 weeks of flower because it is low-stress by design. Anything more invasive than gentle tie-downs should stop by week 2 of flower.