Many marijuana stocks have enjoyed a great year in 2020. Despite the coronavirus pandemic, cannabis has been in high demand among customers, and many states deemed dispensaries to be essential businesses amid widespread lockdowns.  And now, with four more states (Arizona, Montana, New Jersey, South Dakota) legalizing marijuana for recreational use and the economy potentially getting back to normal next year, 2021 could be another strong year for the industry, as the bullishness doesn't look to be ending anytime soon.

Two marijuana stocks that could be great buys in 2021 are Planet 13 (OTC:PLNH.F) and Trulieve Cannabis (OTC:TCNNF). While both stocks are doing great in 2020 and up more than 150% this year (compared to the Horizons Marijuana Life Sciences ETF, which is down 3%), it's still not too late to invest in these companies. Here's a closer look at why 2021 can be another great year for these stocks.

Cannabis plant.

Image source: Getty Images.

1. Planet 13

It's been an impressive year for Planet 13. Despite operating at just 50% capacity, Planet 13's SuperStore location in Las Vegas has been reporting impressive numbers.

On Nov. 24, the company released its third-quarter earnings for the period ending Sept. 30, and sales of $22.8 million were a record high and grew 36.5% from the prior-year period. Planet 13 also turned a modest profit of $0.2 million, which was an improvement from Q3 last year when it incurred a loss of $1.7 million.

The big reason to be bullish on Planet 13 next year is that as coronavirus vaccines are administered and there's a gradual increase in travel, the Las Vegas-based business could be one of the big winners of 2021. The company built the SuperStore to be a huge tourist attraction that could bring in more than just cannabis customers. In October, Planet 13 announced the addition of a non-cannabis retail store to the complex, which it said "will be a one-stop-shop for everything necessary for an enjoyable weekend or weekday in Las Vegas."

If Planet 13 can do this well when operating at half capacity, and with visitor volume still nowhere near where it was before the pandemic began, the sky could be the limit for the company once travel gets back to near-normal levels. And with multiple vaccines potentially on the way, there could be a big uptick in travel numbers as early as next year. In October, visitor volume to Las Vegas was 1.9 million, well shy of the 3.3 million people who visited Sin City in February.

Next year could be a big one for Planet 13, as these latest results could be a drop in the bucket for the company, compared to what it can achieve when the economy is stronger and operations are back near capacity. In 2020, shares of Planet 13 have soared more than 190%.

2. Trulieve

Like Planet 13, much of Trulieve's business has centered around one market. Of the company's 73 dispensaries, 68 are located in its home state of Florida.

While focusing on just one main market has been a successful strategy for Trulieve, branching out into other states will make its business more diverse and its top line even stronger. One state, in particular, that investors should be excited about is Massachusetts, where Trulieve expects to commence operations next year.

The recreational market in Massachusetts has been open for business since late 2018, and within two years, sales topped $1 billion. Researchers project that by 2024, the Massachusetts market could be worth as much as $1.35 billion, growing at an annual rate of more than 18%. That's still a bit behind the Florida market, where medical marijuana sales alone could reach $1.2 billion by next year, up from potentially $950 million in 2020.

On Nov. 17, Trulieve released its third-quarter numbers for the period ending Sept. 30, and sales of $136.3 million were a record for the company, rising 13% from the previous quarter. Year to date, its sales of $353.1 million are more than double the $173.1 million that Trulieve reported over the same period in 2019.

Trulieve's business is strong today and could get even better in 2021 as it enters a hot market like Massachusetts and focuses further on expansion. In addition to Massachusetts and Florida, the company also has a presence in West Virginia, Pennsylvania, California, and Connecticut.

Next year could be a big one for Trulieve as it continues to develop more opportunities outside of Florida. Year to date, the stock is up around 160%.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.