It is quite difficult to say what country was first to grow cannabis under artificial light, as both American growers and Dutch breeders almost simultaneously began to cultivate marijuana indoors in the late 1970s and early '80s. At the time, growing cannabis was illegal even in the most liberal states of America, while weed growers in the Netherlands could legally cultivate marijuana on a large scale. Hence, most cannabis strains we consume nowadays were bred in Amsterdam by the industry pioneers, including Robert C. Clarke, Wernard Bruining, and Ben Dronkers. While California experienced the boom of growing pot indoors only after medical cannabis legalization in 1996, the Dutch were already sharing their experience and equipment with other countries.
There are many seed banks in Europe because marijuana seeds are legal in most countries of the European Union. Thanks to the Schengen Agreement, Europeans can easily buy cannabis seeds even in the countries where marijuana is illegal. Most legal seed banks are located in Spain where professional breeders have been responsible for producing high-quality seeds for more than three decades. Europeans can also benefit from feminized pot seeds or even from feminized and auto-flowering cannabis seeds that ensure a good yield. Only beginners or large producers may decide to grow from regular seeds to sell cuttings from their grow rooms.
In American states where marijuana is decriminalized, weed growers usually cultivate cannabis from clones as legal seed banks are rare. Moreover, most weed strains have illegal origins and were bred by private growers or medical collectives. In those states where weed is still illegal, pot growers exchange cannabis pollen and clones on a private basis to cultivate small batches of illegal weed seeds or to breed new pot strains.
The main difference in growing conditions lies in the costs of energy and material safety in Europe and the U.S. For example, energy in America is cheaper than in the EU. Hence, most European growers choose 400-600-watt bulbs, while Americans can afford growing marijuana under 1,000 watts. Moreover, all electronic devices in North America run on 120 volts, while electronic equipment in the EU consumes 230 volts.
As for grow boxes, almost all weed growers in America prefer boxes with a silver inner layer, while Europeans use white tents that reflect light better. The reason is that first white grow boxes that appeared in America received a bad reputation because of PVC, or polyvinyl chloride, that caused the death of cannabis plants. And though nowadays, cannabis boxes are covered with safe white PE, or polyethylene, most U.S. growers still choose silver tents.
For harvesting marijuana buds, European growers use special trimming machines, while in North America, this equipment is popular with neither growers nor consumers. Almost all cannabis growers in the U.S. and Canada still trim their plants by hands, but in the EU, weed producers use trimming equipment even for cutting their mini-grow setups.
There is also a difference in processing marijuana trichomes and crop in Europe and North America. While Americans widely use silicone mats and other accessories for extraction, most Europeans still use plastic tubes and denatured lighter gas for creating cannabis extracts.
Though there are some differences in cultivating cannabis indoors between the EU and North America, marijuana growers on both sides of the pond have similar experiences and problems.