To say that there have been big changes in the Canadian cannabis landscape in recent months would be a major understatement. Although Canada was expected to be a global marijuana pioneer given that it was the first industrialized country in the modern era to green-light recreational pot, a number of regulatory issues have stymied growth. As a result, most Canadian pot stocks continue to lose money, and many have needed to adjust their game plans, accordingly.

Perhaps the magnitude of these changes is best served by comparing peak production estimates for Canada's top-tier growers in early June 2019 to what those peak output estimates look like in February 2020, inclusive of pending asset sales and construction project halts.

Ranking Canada's top cannabis growers

Back in June, I ranked Canada's growers by peak production, which looked like this:

1. Aurora Cannabis (NYSE:ACB): 662,000 kilos.
2. Canopy Growth (NYSE:CGC): 500,000 to 550,000 kilos.
3. Aphria (NYSE:APHA): 255,000 kilos.
4. CannTrust Holdings (NYSE:CTST): 200,000 to 300,000 kilos.
5. The Green Organic Dutchman (OTC:TGODF): 219,000 kilos.
6. HEXO: 150,000 kilos.
7. Aleafia Health: 138,000 kilos.
8. Zenabis Global: 131,300 kilos.
9. Cronos Group: 117,500 kilos.
10. OrganiGram Holdings: 113,000 kilos.

Today, just eight months later, the top five Canadian marijuana growers by peak production have changed considerably:

1. Canopy Growth: 500,000 to 550,000 kilos.
2. Flowr Corp. (OTC:FLWPF): 500,000+ kilos.
3. Aphria: 255,000 kilos.
4. Aurora Cannabis: Approximately 230,000 kilos.
5. Aleafia Health: 129,500 kilos.

In short, the previous projected leader has fallen to No. 4, a grower that wasn't even in the top 10 in June is likely to now be a core producer, and a number of major growers have fallen way down the list for a variety of reasons.

What happened to previously top-tier growers?

As you've probably noticed, Aurora Cannabis had one of the more notable descents among Canadian marijuana growers by peak production. This decline has to do with a combination of more accurately matching output with market demand, as well as conserving cash. Aurora Cannabis announced in November that it would immediately halt construction at its 1.62-million-square-foot Aurora Sun facility in Alberta, and its 1-million-square-foot Aurora Nordic 2 campus in Denmark. With the exception of utilizing 238,000 square feet of cultivation space at Aurora Sun, this effectively idles around 325,000 kilos of annual run-rate output.

But that's not all for Aurora. It also recently put the 1-million-square-foot Exeter greenhouse up for sale. Exeter will need to be retrofitted to grow cannabis and is projected to yield 105,000 kilos at peak operating capacity. With these cultivation assets stripped from the equation, Aurora Cannabis only has the potential to produce around 230,000 kilos a year. As long as financing remains a concern, don't expect Aurora Cannabis to expand its output anytime soon.

You're probably also wondering what on Earth happened to CannTrust and Green Organic Dutchman? As for TGOD, as Green Organic Dutchman is known, it was the first to announce a significant cutback in output to match Canada's subdued launch and supply problems. Instead of aiming for 219,000 kilos in peak output, TGOD's fiscal 2020 production is expected to target only 20,000 to 22,000 kilos for the year.

Then there's CannTrust, which had its cultivation and sales licenses suspended by Health Canada in September. This follows an admission that the company had illegally grown weed in five unlicensed rooms over a period of six months between October 2018 and March 2019. With no guarantee that it regains its licenses, or is able to expand its outdoor cultivation assets, CannTrust's 200,000 to 300,000 kilos is a big zero for the moment.

A number of other growers, including OrganiGram, HEXO, and Cronos, have also halted construction on expansion projects or repurposed existing space that had been used for cultivation.

A select few growers have stood firm on production

On the flipside, a small number of growers have held firm on their peak production estimates, or perhaps even increased their capacity.

For example, you probably noted Flowr at No. 2, and you may not have even heard of the company before. As of June, Flowr was entirely focused on its Kelowna campus in British Columbia, which is capable of around 50,000 kilos of premium and ultra-premium cannabis products. It also envisioned another 300,000-plus square feet of outdoor and greenhouse grow adjacent to Kelowna. But none of this made it anything more than a mid-tier producer. What vaulted Flowr into the spotlight was its acquisition of Holigen last year, giving it ownership of the Aljustrel outdoor grow farm in Portugal, capable of up to 500,000 kilos of peak annual output. This added production makes Flowr a logical player in the burgeoning EU medical marijuana market.

You'll also note that estimates for Canopy Growth and Aphria haven't changed since June. Canopy Growth tends to keep a very tight lid on its growth projections, so this has more to do with not getting any specific company updates on output than any direct commentary from management.

Meanwhile, Aphria (finally) received its cultivation license for Aphria Diamond in November. This joint venture cultivation project should account for 140,000 kilos of Aphria's 255,000 kilos in peak annual output. Though it remains to be seen if all of this production is actually needed, Canopy Growth and Aphria appear to have dug in their heels as leading marijuana growers in Canada.