Indica makes you sleepy, Sativa makes you alert. Indica is small and bushy, Sativa is tall and slim. This simplification has two problems: it is not scientifically tenable, and it leads to bad purchasing decisions for your setup.
The botany is more complicated — and more useful than the marketing catalogue suggests.
The botanical reality — what Indica and Sativa actually describe
The terms Cannabis indica and Cannabis sativa originally describe the geographic origin and morphological characteristics of wild plants. C. sativa from equatorial regions (long vegetative period, narrow leaves, height). C. indica from Central Asia (short vegetative period, broad leaves, more compact structure). C. ruderalis from Russia and Central Asia (short growth period, autoflowering — flowering independent of light rhythm).
The problem: through decades of intensive crossbreeding, hardly any "pure" line still exists. What is sold today as "Indica" or "Sativa" is in nearly every case a hybrid with mixed genotype. The differences in effect between modern Indica- and Sativa-dominated strains do not arise from taxonomic affiliation, but from terpene profile and cannabinoid ratio — which cannot be reliably derived from the Indica/Sativa label.
Phenotype: the visible characteristics (height, leaf shape, flowering time, yield)
Genotype: the genetic information — defines the phenotype frame
Terpene profile: primarily responsible for aroma and effect character
Cannabinoid ratio (THC:CBD): intensity and type of effect
Photoperiodism — what triggers flowering
Standard cannabis strains (photoperiod) flower in response to day length. Concretely: they flower when the dark phase is extended to 12 hours. That corresponds to the natural transition from summer to autumn. Indoors, that means: the grower triggers flowering by switching the light cycle from 18/6 to 12/12.
Autoflowering strains (C. ruderalis crosses) flower on a time schedule — independent of the light cycle, typically 3–5 weeks after germination. The advantage: no manual light switch needed, shorter total duration (50–80 days), can be cultivated under 20h light without issues. The disadvantage: no training during flowering, smaller training window overall, often slightly lower flower quality than top photoperiod strains.
| Property | Photoperiod | Autoflowering |
|---|---|---|
| Flowering trigger | Light cycle (12/12) | Age (3–5 weeks) |
| Total duration | 16–24 weeks | 8–12 weeks |
| Training options | Full (LST, Topping, SCROG) | Limited (LST recommended) |
| Yield (typical) | High | Medium |
| Harvest timing control | Full | Limited |
| Light requirement | 18h veg · 12h flower | 18–20h entire cycle |
For compact setups like the Growix Core — which criteria matter
A 140 × 40 × 40 cm setup defines clear parameters. These are the relevant strain criteria in this order:
1. Final size (phenotype height)
In the Growix Core you have approximately 100–110 cm of usable growing space after subtracting pot height and lamp distance. Strains with "tall" or "XXL" in their name are unsuitable. Suitable: strains that reach 60–90 cm, or strains with a known stretching factor (height increase upon flip from 18/6 to 12/12). Stretching can mean 50–150% of vegetative height — that must be factored in.
2. Flowering time
Shorter flowering times (7–9 weeks) are more efficient in small setups — more grows per year, less time in the resource-intensive flowering phase.
3. Trainability
Some strains respond poorly to aggressive topping — slow recovery, persistent apical dominance. For LST and SCROG in small format, indica-dominant or balanced hybrids are often better suited than sativa-dominant strains with strong apical dominance.
4. Resistance
Mould resistance is more relevant in a 40 × 40 cm setup than in a large grow tent — less air circulation between flowers, higher flower density relative to room volume. Prefer strains with known Botrytis resistance.
| Criterion | Priority for Growix Core | Why |
|---|---|---|
| Final size < 90 cm | Critical | Room height limited |
| Flowering time < 10 weeks | High | Annual efficiency |
| LST-suitable | High | Width over height in 40×40 format |
| Mould resistance | Medium-High | Confined space, denser flowers |
| Yield | Medium | Quality before quantity in small setups |
| Terpene profile | Personal preference | Scientifically still incompletely understood |
Feminised vs. regular seeds
Regular seeds produce around 50% male plants. Male plants pollinate females — the result is seeds instead of resin. For the home grower without breeding interest: feminised seeds are the standard. They guarantee > 99% female plants.
Hermaphroditism (intersex development) often arises from stress — too much light during the dark phase, extreme temperature changes, mechanical damage. Feminised seeds genetically have a slightly higher tendency toward hermaphroditism than regular seeds — irrelevant under normal conditions, but a risk under high stress.