Cann Group is designing a huge glass roof for its mammoth cannabis-growing facility at Melbourne Airport — one of the first of its type in the world.

Plans for the Melbourne site — announced in June — are being drawn up by Canadian greenhouse designer Aurora Larssen. The $100 million facility is expected to be ready by June.

“We’re the only company in the world that has built and is building mass-scale indoor [cannabis] production facilities with a glass roof but also a closed system,” Aurora Cannabis chief corporate officer Cam Battley told Stockhead.

Aurora — the world’s second biggest pot stock and Cann Group’s (ASX:CAN) biggest shareholder with 23 per cent — bought the greenhouse designer last year.

“It’s not open to the air, so nasty things can’t blow in, and we have precise control over the environmental variables which allows us to produce cannabis that is exceedingly clean,” Mr Battley said.

Mr Battley believes the glass-roofed Melbourne plant could produce more than the six cannabis harvests that standard indoor growing facilities average.

An early design for Cann Group's Melbourne cannabis-growing facility. Source: Cann Group annual report
An early design for Cann Group’s Melbourne cannabis-growing facility. Source: Cann Group

Natural or artificial light?

There are differing views on whether glass roofs are the most effective way to grow cannabis, however.

Dr Trevor Garnett, a director at Adelaide university’s Plant Accelerator, says glass is great for transmitting the natural light that plants like. On the other hand artificial light is expensive to run and needs precisely the right globes that feature wavelengths plants prefer.

He says we know from years of experimentation by illegal cannabis growers what kinds of bulbs work best.

The other camp claims glass makes temperature-control more complicated because it can magnify heat which prevents control over seasonality.

Canadians investing in Aussie pot stocks

Aurora is not the only big Canadian cannabis player to invest in the Australian marijuana market.

Alongside Aurora’s stake in Cann, Canopy Growth has 11.2 per cent of AusCann (ASX:AC8) and Aphria has 25 per cent of Althea Group (ASX:AGH).

Canopy is the largest pot stock in the world by market cap and Aphria is number five.

Some investors wonder whether the Canadian interest is a sign that local companies are takeover targets or whether the stakes are defensive.

Cann’s stock surged earlier this year on rumours Aurora had made an offer. Mr Battley would not comment on whether they have or not.

Canopy has set up an office in Victoria apparently in competition with AusCann.

Last week at a major cannabis conference in Sydney, Arnold Bloch Leibler lawyer Jeremy Leibler said while he’d seen many companies get benefits like Intellectual property rights, sales agreements and know-how from their Canadian “big brother”, it was uncertain whether those companies intended to use those companies as their sole vehicle in Australia.

Local players were faced with the prospect of having a major shareholder which, in the case of AusCann at least, could also be a competitor.

Mr Battley says there is nothing to worry about from Aurora, however.

“We’re good people and we mean well. Obviously we have a commercial interest, but we have a lot to bring and we see Australia being a significant player in the global cannabis market,” he told Stockhead.

“As much as Aurora intends to and plans to play a leading role in the growth of the medical cannabis sector, we know we can’t do it alone, nor is that our way of doing business.”