Just guessing is totally fine – it's only about a first impression.
There is no standardised mould-resistance test for cannabis varieties. What you read there is at best an observation, often just a sales attribute. That doesn't automatically make it wrong – but you should know you are buying a claim, not a measurement.
The breeding course has a sentence that counts double outdoors: selection environment equals target environment. Choose a plant where it will later stand and you choose well – choose it in a tent and you choose for the tent.
This isn't theory, it's the reason a variety that runs beautifully in California collapses in a German September. It was never selected in a German September.
Translated for you: two growers in the same country may need different varieties if one stands on a windy slope and the other in a damp hollow.
"Indica for short flowering, sativa for long" – that's how nearly every shop sorts things. How well does that label predict the actual genetics?
It explains about a third. A genome study compared the sativa/indica designation with actual genetic similarity: coefficient of determination 0.36.
It gets starker with names: in 35 per cent of identically named variety pairs, each of the two plants was genetically closer to a differently named variety than to its own namesake.
The name on the packet follows the trade, not the ancestry. For your choice that means: the origin of the genetics tells you more than the label – and your own observation more than both.
What you'd actually need is a table: variety X ripens up to latitude Y by date Z. That table does not exist.
We looked. For fibre and CBD hemp there are real field trials – universities and agricultural boards test varieties over years and publish flowering and harvest windows. For drug-type varieties there is nothing comparable. What circulates is seller information and forum experience.
That's not a catastrophe, but it changes what you lean on:
First, the origin of the genetics – a mountain landrace from the north brings an early date with it, that's biology and not marketing.
Second, grow diaries from people at your latitude – not representative, but at least real.
Third, your own record from last year. That's the best source you will ever get.
It has been investigated, and the finding is the opposite: indica types come from arid regions and are precisely not adapted to high humidity. Their dense inflorescences hold moisture in – making them especially prone to bud rot. Tough against cold and drought does not mean tough against wet. The structure sold as a quality in the catalogue is the risk in a wet autumn.
You will never get rid of claims – but you can translate them. Three questions are enough:
Who says this, and what do they gain? Whoever sells the genetics is not neutral. That doesn't make the statement false, but it makes it worth checking.
Is it a number or a feeling? "Flowers early" is an experience. "Flowers at 18 hours" is a measurement – and measurements can be cross-checked, as in the last lesson.
Does it fit the biology I know? That's the strongest question, because you can answer it without any sources. A threshold above the longest day at the place of origin cannot exist. Neither can a variety that responds to light and yet flowers independently of it.
Three questions, none of which needs a laboratory.
🎯 Hands-on mission
Take a variety description you have in front of you and run it through the three questions: who says it, is it a number or a feeling, does it fit the biology? You'll be surprised how much survives – and how little of it is a measurement.
To the knowledge base →✓
Suppose you chose well. Then September arrives – and with it the one opponent no variety alone can handle.
Something still unclear?
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