Search for the strongest indica strain and you will find lists ranked by a single THC percentage. For a collector those numbers are worth understanding, because they are the most misquoted figures on any seed listing. This guide explains where reported THC data comes from, how to read it, and which indica lines are most consistently cited at the top of the range.
It is written for UK adults collecting seeds as souvenirs. It does not describe cultivation or the effects of any plant; every figure is reported breeder or seed-bank reference data.
Where a THC figure comes from
A THC percentage on a listing is a report of a laboratory test on flower produced by the breeder or by a licensed producer, usually in the United States or Canada. It describes one sample, from one selection, under one set of conditions. That is why serious breeders publish a range, and why a seed bank in the UK, which cannot legally produce or test anything, should present the figure as reported data rather than a promise.
How to read the number
- Ranges are more honest than single figures. “22–26%” tells you the breeder tested more than once.
- Attribution matters. A figure linked to a breeder’s own published data is worth more than one with no source.
- Terpene totals tell a different story. Some breeders publish total terpene content alongside THC; the two are not the same measure.
- The same name can test differently. Because strain names are not protected, two “Gorilla Glue” listings can describe different selections. why the same strain name can mean different genetics explains.
Indica lines most often cited at the top of the range
| Gorilla Glue #4 (GG4) | Chem’s Sister x Sour Dubb x Chocolate Diesel; reported 25–30% in breeder data. Indica-leaning hybrid. |
| Wedding Cake | Cherry Pie x GSC; reported above 20%, with 25%+ quoted for some selections. |
| Blue Zushi | Zkittlez x Kush Mints; reported 22–26% with laboratory terpene totals reaching 2.6%. |
| SFV OG | San Fernando Valley OG Kush selection; reported 20–24%. |
| Purple Punch | Larry OG x Granddaddy Purple; reported 18–22%, cited more for aroma than potency. |
| Afghan and Hindu Kush landraces | The genetic source of the indica category; reported figures are usually lower than modern hybrids but resin production is heavy in breeder descriptions. |
What the number does not tell a collector
Reported THC is one attribute among several. Lineage, breeder reputation, terpene profile and how well the line is documented are usually better guides to whether a listing is worth holding. A collection built only around the highest reported percentage tends to end up full of similar Cookies and GG4 crosses; one built around families and heritage is more interesting and easier to verify. indica, sativa and hybrid seeds explained sets out the wider picture.
Where to find these lines
The indica seeds category lists the indica-dominant seeds Canna Genetics stocks as collectibles, including Gorilla Glue Auto, Wedding Cake feminised seeds, Blue Zushi and SFV OG. Each listing gives the reported range and its source, in 1- and 3-seed packs.
Frequently asked questions
By reported breeder data, Gorilla Glue #4 is the most consistently cited, at 25–30% THC potential, followed by Cookies-family lines such as Wedding Cake and newer selections like Blue Zushi. All figures are reported, not tested by Canna Genetics.
Because the figure comes from a laboratory test of one sample from one breeder’s selection, and strain names are not protected, so two listings with the same name can describe different genetics.
A range attributed to a breeder’s published data is more reliable than a single figure with no source. Treat one round number as marketing.
No. A UK seller cannot legally produce or test cannabis, so any figure it shows is reported breeder or seed-bank data and should be labelled that way.
Yes. The seed itself contains no controlled cannabinoids and is legal to buy and collect in the UK as a souvenir. Germination and cultivation are illegal without a licence. Canna Genetics sells to adults aged 18 and over only.
Collector note and UK law
Canna Genetics sells every seed strictly as a collectible souvenir for adults aged 18 and over. We do not provide germination or cultivation advice, and all strain data on this page is reported breeder and seed-bank reference information, not a description of anything we have grown. Read our UK seed legality guide for the full picture.
Compare reported ranges across the indica seeds category, or the full full Canna Genetics collection.
