Watch the episode · 2:35Autoflowers are sold as the easy option: plant a seed, wait about ten weeks, harvest. So why do so many end up tiny, stunted and disappointing? The answer is in their genes. Autoflowers run on a fixed clock that never stops, so mistakes a regular plant would shrug off become permanent. And mistake five is one even breeders get wrong.
Mistake 1: cutting the light ▶ 0:30
Treating an auto like a regular plant. Regular plants need 12-hour nights to flower, but autos flower by age, as episode 3 on autoflowers explained. Cutting their light doesn't trigger anything; it just cuts their energy. In one indoor study of cannabis, yield rose steadily as light intensity went up.
Source · Rodriguez-Morrison et al., Frontiers in Plant Science (2021)
Mistake 2: late transplants ▶ 0:53
Stressful transplants. A regular plant can sit in its growing phase as long as you like, so it has time to recover. An auto can't. Think of it as a train that leaves on time whether or not you are on board. Many growers sow autos straight into their final pot. (Does pot size matter for autoflowers? looks at the research.)
Mistake 3: late, heavy training ▶ 1:13
Heavy training, too late. Cutting off the top or bending hard puts a plant on pause while it recovers. The growing window of an auto is only a few weeks long, so any training should be gentle, and early.
Mistake 4: cloning autos ▶ 1:29
A cutting is the same age as the plant it came from, so a clone from a six-week-old auto is a six-week-old plant. It starts to flower almost straight away, while it is still tiny.
Mistake 5: the breeder's trap ▶ 1:45
The one that catches breeders: cross an auto with a regular plant and expect autos. Every seed carries one copy of each version, and the main auto gene is recessive, so not one of them flowers by age.
Cross those offspring together and about one in four autos comes back. It is a two-generation job, at least.
Source · Toth et al., Frontiers in Plant Science (2022)
Every one of these mistakes comes back to the same fact: an autoflower's clock starts the day it sprouts. Why it can never be paused is down to a single gene, explained in the autoflower gene, and why some autos stay small anyway is in why is my autoflower so small?
Sources
- Rodriguez-Morrison, V., Llewellyn, D. & Zheng, Y. (2021). "Cannabis Yield, Potency, and Leaf Photosynthesis Respond Differently to Increasing Light Levels in an Indoor Environment." Frontiers in Plant Science 12: 646020.
- Toth, J.A. et al. (2022). "Identification and mapping of major-effect flowering time loci Autoflower1 and Early1 in Cannabis sativa L." Frontiers in Plant Science 13: 991680.
Every claim in this article comes from the episode script, which is checked against these papers. Prices on Seedscanner are dated observations; this page is not growing or legal advice.
