Flower gets the glory, but veg decides the yield. Every branch, node, and root you build now is infrastructure the plant will load with bud later. A plant that enters flower small, rootbound, or unhealthy doesn't magically fix itself — the ceiling was set in veg.
The environment
| Factor | Target |
|---|---|
| Light cycle | 18/6 |
| Temperature | 24–28 °C lights on, 20–22 °C off |
| Humidity | 50–65 % RH |
| Water pH | 6.0–6.8 (soil), 5.5–6.1 (coco/hydro) |
| PPFD | 400–600 µmol/m²/s |
Photoperiod plants stay in veg as long as the light cycle stays at 18/6 — that's your throttle. More veg time means a bigger plant and a bigger harvest, at the cost of calendar time and space. Most indoor growers veg for 4–8 weeks depending on pot size and training goals.
For the full environment breakdown — temperature, humidity, and airflow targets by stage — see the environmental control guide.
Feeding
Veg is nitrogen season. A typical N-P-K for this stage looks like 3-1-2.
- Start at half the label dose and work up; labels are written by people selling nutrients
- Feed, feed, water is a solid soil rhythm — the plain-water round flushes salt buildup
- Leaf color is the gauge: deep green is fed, pale green-yellow (starting at the bottom) is hungry, dark blue-green with clawed tips is overfed
- Track your input EC/PPM with a meter — it removes the guesswork from "half strength." See the EC/PPM measuring guide
Feeding by week (general soil schedule)
| Veg week | EC target | Notes |
|---|---|---|
| 1–2 (post-seedling) | 0.4–0.8 | Quarter to half strength |
| 3–4 | 0.8–1.2 | Working up to full veg dose |
| 5–6 | 1.2–1.6 | Full veg, watch for tip burn |
| Pre-flip week | 1.0–1.4 | Slight ease-off before transition |
Coco growers: feed every watering (no plain-water rounds) and keep EC slightly lower — coco holds nothing on its own.
If leaves are yellowing or showing spots during veg, check the nutrient deficiency chart — but start with pH before adding anything. Nine times out of ten, the nutrient is in the soil but locked out by wrong pH.
Transplanting
Roots that hit the pot wall circle it and strangle growth. Move up pot sizes when leaves span wider than the current pot — typically solo cup → 1 gal → 3–5 gal final.
Transplant technique:
- Water the plant lightly 12–24 hours before (moist roots hold together; soaked ones are heavy and fragile)
- Fill the new pot with medium, carve a hole the size of the old pot
- Flip the old pot, slide the root ball out by the base — never grip the stem
- Set it in the hole, fill gaps, and water lightly to settle
Expect 1–2 days of stall after transplanting — the roots are exploring new soil. Don't feed heavy during this window. For a deeper dive, see the transplanting guide. If the plant wilts badly, see transplant shock recovery.
Canopy: the 80/20 of yield
Light only penetrates the top ~30 cm of canopy effectively. A plant shaped like a Christmas tree wastes most of it. Your goal is a flat, wide table of evenly-lit tops.
- Topping — snip the main growing tip above the 4th–5th node; the plant redirects to two main colas instead of one
- LST — bend and tie branches outward so light reaches everything
- SCROG — weave branches through a horizontal net to lock the canopy flat
- Remove growth that will never see light: the spindly bottom third (this is called lollipopping — see the defoliation guide)
The combination of topping + LST is the standard indoor recipe: top once at node 4–5, then bend the two resulting mains outward and keep spreading as the canopy fills. For a side-by-side comparison of all methods, see training techniques compared.
Signs veg is going well
- New node every 2–3 days — steady vertical and lateral growth
- Thick stem — you should feel resistance when you gently flex it; thin stems mean weak light or no air movement
- Even color — consistent green across the canopy without yellowing, spotting, or clawing
- Branching out — side branches growing aggressively, especially after topping or LST
Common veg-stage problems
| Symptom | Likely cause | Fix |
|---|---|---|
| Slow growth, pale leaves | Underfeeding or pH off | Check pH first, then bump feed |
| Dark clawed tips | Nitrogen toxicity | Flush and reduce N. See nitrogen toxicity guide |
| Stretchy, tall, thin | Light too high or too dim | Lower light or increase dimmer. See lighting guide |
| Leaf edges curling up | Heat or light stress | Raise light, improve airflow. See light burn guide |
| Roots poking from drainage | Rootbound — transplant now | Move to next pot size |
When to flip
Plants roughly double in height during the flowering stretch. Flip to 12/12 when your plant fills about half its allotted final height and the canopy is even. For most indoor grows that's week 6–8 of veg.
Flip readiness checklist:
- Plant is at 50% of max tent height (after accounting for pot + light hang distance)
- Canopy is flat and trained — uneven canopies get worse during the stretch
- No active deficiencies or pest issues
- You've finished all topping/training at least a week ago so the plant has recovered
See the flip guide for the full transition checklist and what changes in the tent.