Mainlining — also called manifolding or fluxing — is the most methodical training technique in cannabis. Where LST bends branches into position and SCROG uses a net to enforce evenness, mainlining builds symmetry into the plant from the third node. Every branch is the same length, the same thickness, and carries the same amount of nutrients. The result: a plant that looks like a candelabra, with 8 or 16 colas of identical size.
It takes longer than any other training method — typically 2–4 extra weeks of veg. But for growers who want perfectly uniform buds from every harvest, there's no substitute.
How mainlining works
The principle
Every cannabis plant has a main stem that delivers nutrients from the roots upward. When you top the plant, you split that delivery into two branches. Top each of those, and you have four. Top again: eight. Each split is symmetrical — the same node position, the same angle, the same distance from the root crown.
This matters because of apical dominance. In an untopped plant, the main stem gets priority nutrient delivery (auxin gradient). Side branches are subordinate. In a mainlined plant, every branch IS a main stem — they all originate from the same split points and receive equal nutrient flow. No branch is dominant. No branch is subordinate.
Why not just top normally?
Regular topping creates two branches, but they're not truly equal. The node position, branch angle, and distance from the root vary. Over time, one branch dominates and the other lags. You can correct this with LST, but you're fighting the plant's natural tendency.
Mainlining eliminates the fight by removing everything except the symmetrical branches. There's nothing to compete with — every branch is structurally identical.
The build: step by step
Step 1: Let the plant grow to node 5–6
Don't touch the plant until it has 5–6 nodes (pairs of leaves). This takes about 3 weeks from sprout. You need this height because you're about to remove most of it.
Why node 5–6? The stem at this height is woody and strong enough to handle the stress of topping and the weight of two trained branches. Topping at node 3 (as some guides suggest) works but produces thinner branches that are easier to snap.