For the first time, Canadians are busy planting weeds in their gardens, rather than trying to prevent them.

Or more accurately, they're planting "weed" in their gardens.

The federal Cannabis Act specifies that each household can cultivate up to four plants — either indoors or out. Manitoba and Quebec have opted to prohibit homegrown cannabis, but there's already evidence Canadians in other provinces are set to take advantage of the herb's newly legal status.

"I'm really excited to be able to grow it," says Matt Soltys, a father of two in Guelph, Ont., and a student of botany at the University of Guelph. "I'm not even a big user of cannabis, but I'm excited to have it in my garden without the stigma or the illegality."

Soltys planted four seeds indoors in February. They've grown to about half a metre high, bushy in pots, ready to be planted in his back garden now that the weather is warm enough.

"They're pretty healthy," says Soltys, who also offers workshops on how to grow and harvest cannabis. "They could easily get to 6 feet [1.8 metres] tall, 6 feet wide."

Cannabis garden centre

Alex Rea's family has been in the gardening business since 1985. Toronto-based Homegrown Hydroponics has four locations in Ontario and has specialized in growing cannabis indoors hydroponically, selling a wide selection of lights, fertilizers and other supplies.

But Rea and his staff say they've seen a lot of new faces coming in the door recently, asking questions about the best way to cultivate cannabis outside in gardens or planters.

Alex Rea's family has a chain of stores that specialize in hydroponics. He and his staff have had new customers coming in to ask about growing cannabis outdoors. (Rob Krbavac/CBC News)

"Outdoor production is definitely cheaper," he says. "There is less equipment involved, and it's more environmentally friendly. There is no input of electricity to power grow-lights, for example."

He adds that no matter where people grow their cannabis, there is a cost advantage to doing it yourself.

"For the price-conscious consumer, if you're paying around $10 a gram for the varieties at the store, you might be only paying 50 cents per gram or less for a variety you grow yourself at home," says Rea.

Seed shortages and big prices

It's difficult to know yet just how many Canadians are taking advantage of the new opportunity to grow recreational cannabis at home. But demand is already outstripping supply, since a number of provincial authorities are reporting seed shortages.

Alberta says there's a "very limited" supply of seeds in the province, and at the Ontario Cannabis Store, only one strain is currently available. A package with four seeds costs $58.

CBC News contacted every province, and only Nova Scotia was able to specify the level of demand for seeds, saying that weekly sales have risen to a modest 14 packages of four seeds each in May from 10 packages back when the seeds were first offered for sale in February. The provincial distributor says it expects to be able to fill orders.

Shega Youngson of Canopy Growth shows what $58 can buy you: four Baker Street brand indica cannabis seeds, sold at the Tokyo Smoke retail chain. (Jon Castell/CBC News)

Canopy Growth, one of Canada's largest licensed producers, is also working to get more seed varieties into the system across the country.

"Legalization is new, Oct. 17 was just a few months ago," says Shega Youngson, a spokesperson for the company. "Once we have a broader selection, I think that people will want to try it out."

Kelowna, B.C.-based licensed cannabis producer Flowr currently has no seeds for sale, but its director of plant science says that by June, the company will have both seeds and "clones" available.

"Clones are a cutting from a high quality, high producing mother plant," Deron Caplan said. "Right now, we're trying to find retailers we trust who can keep the clones alive. It's not as simple as seeds."

Scott's Miracle Gro for cannabis?

Scott's Miracle Gro, one of the best known brands of fertilizer for lawns and gardens, has a cannabis division, the Hawthorne Gardening Company, based in Surrey, B.C. Its focus has been on large commercial growers of cannabis, as well as hydroponics. Now it's developing products aimed at cannabis hobbyists in the consumer market.

But is special fertilizer even needed? In his backyard in Guelph, Matt Soltys says that growing cannabis isn't much different from growing tomatoes.

"I give it good compost and good water, good soil, access to enough light, and it knows what to do," he says. "It's a very hearty and forgiving plant, so there's not a lot of maintenance you need to do."

Deron Caplan earned a PhD in cannabis horticulture at Guelph University, the first in North America. He's now the director of plant science at Flowr, a licensed producer in Kelowna. (Stephanie Masina/Flowr)

Deron Caplan of Flowr — who has a PhD in cannabis horticulture — says fertilizer will indeed improve the quality and quantity of cannabis plants, although it may not be necessary to buy a brand specially designed for cannabis.

"For new growers at home, they'll do very well with an off-the-shelf fertilizer geared toward something like tomatoes," he says.

Police and homegrown weed

Weed gardeners evidently have little to fear in the way of police enforcement.

In response to a query from CBC News, the Vancouver Police Department said its strategy "continues to target those drug producers who show a high level of organization and co-ordination, and those who manufacture opioids and other harmful drugs for profit."

Don Belanger of the Toronto Drug Squad says his team has no set protocol for homegrown weed.

"To suggest that we're going to have teams of officers peeking in people's backyards to see if they're growing four plants, it's just not realistic," he says, adding that the drug squad will only investigate if there's a complaint.

As for Matt Soltys, he's looking forward to a good harvest in the fall.

"It'll start to flower mid-to-late summer and be ready to harvest usually mid-to-late September or early October."

In his backyard in Guelph, Ont., botany student Soltys says he's excited to grow cannabis legally. (Rob Krbavac/CBC News)

He only has one worry: people stealing his stash.

"I advise people to plant it with visibility from neighbours in mind, behind fences or bushes — although you can't do much about the scent of it when it's in full flower unfortunately."