The short answer
Chem Dawg finishes indoors in about 8 to 10 weeks after you flip to 12/12, and 9 weeks (roughly day 63 to day 70) covers most of the cuts going around. Some plants want 10 or 11. A few fast Chem 4 leaning plants are done closer to day 56. Treat any breeder number as a range with a soft middle, not a date on a calendar. Plan for 9 weeks, then check the plant instead of the clock.
The reason the spread is wide is genetic. Chem Dawg is not one plant. It is a family of related clones, Chem '91, Chem D, Chem 4 and Chem's Sister among them, and they do not all ripen on the same schedule. Seeds from a Chem Dawg cross can throw plants that finish a week or more apart from each other in the same tray.
How the 9 weeks usually break down
- Week 1 to 3: stretch. Chem Dawg can double or more in height, so flip earlier than feels right. Bud sites set by the end of this window.
- Week 3 to 5: flower formation. White pistils cluster, resin starts showing on the sugar leaves and the smell turns on.
- Week 5 to 7: swell. Calyxes stack and the buds put on most of their weight. This is when the plant eats the most and drinks the most.
- Week 7 to 10: ripening. Pistils darken and recede, trichomes go from clear to milky, then amber. Bud density stops changing much.
What actually moves the harvest date
Light intensity is the big one. A plant under strong, even PPFD in weeks 5 through 8 will finish nearer the early side of its range than the same cut run under weak light. Root zone temperature and container size matter too. A plant that gets root bound in a small pot stalls out and pushes harvest back a week without any obvious symptoms.
Feed timing is next. A heavy nitrogen load late in flower keeps leaves green and pushes the finish out. I taper nitrogen after week 5 and let the plant fade on its own. Temperature swings also slow ripening. Cool nights in the low 60s are fine, a cold room is not.
Chem Dawg Strain Lineage Guide
Stress counts as well. Heavy defoliation in week 6 will cost you time. So will a light leak or a timer hiccup. Chem Dawg is not a fussy plant, but it reacts to interruptions.
Read the trichomes, not the pistils
Pistils are a rough signal only. They can darken early from being brushed or from heat, while the plant is still a week from ready. The reliable check is trichomes on the calyxes, not on the sugar leaves. Sugar leaf trichomes ripen ahead of the bud and will fool you into chopping early.
I look for mostly milky heads with a scattering of amber, somewhere between 5 and 15 percent. Clear heads mean wait. Amber is a personal preference, more of it means a heavier, more sedative effect. Chem Dawg carries enough resin that a cheap loupe is all you need to see it clearly.
Indoor notes specific to this strain
- Stretch control: flip at about half your target final height, or scrog it and fill the net first.
- Smell: the diesel and fuel aroma is loud from week 3. Run a carbon filter from the start of flower, not once you notice it.
- Humidity: buds get dense and hold moisture. Keep late flower humidity around 40 to 50 percent and keep air moving under and through the canopy.
- Support: branches carry weight poorly on some phenos. Stakes or yoyos go in before week 6, not after the first branch folds.
- Feeding: a steady, generous eater, but keep the late-flower mix light on nitrogen.
Harvest and the wait after
Chop at the trichome stage you actually want, not at the first sign of amber. Dry slowly, around 60 to 65 F and 55 to 60 percent humidity, for 10 to 14 days if the buds are thick. Then jar and cure for three to four weeks. The fuel and chem notes sharpen in the jar, and the smoke smooths out. Rushing the cure is the most common way to lose what the extra week of flowering bought you.