REGINA -- Liberal Leader Justin Trudeau made his first campaign trip to the Saskatchewan heartland Wednesday with the message that his party will grow the economy not from the "top down," but from the "heart outwards."

Speaking at a farmers market in Regina, Trudeau said putting more money in the pockets of the middle class is the ticket for his party to win more support in Saskatchewan, where the Liberals have only one seat and Stephen Harper's Conservatives hold the rest.

"We're proposing a strong and real plan, one that invests in the middle class so that we can grow the economy not from the top down the way Mr. Harper wants to, but from the heart outwards," said Trudeau.

"That's what Canada has always done well with."

Saskatchewan has been fertile ground for the Conservatives in recent federal elections. The governing party took 13 of 14 seats in each of the last two votes. Liberal stalwart Ralph Goodale has been the only non-Conservative to consistently win a seat in recent elections.

But re-drawn riding boundaries that have replaced eight urban-rural seats in Regina and Saskatoon with five mainly urban ridings in the two cities have observers suggesting there will be some interesting races this time around.

The Liberals also have high hopes for the northern Saskatchewan seat of Desnethe-Missinippi-Churchill River, which they last won in 2006. The party's candidate, former Federation of Saskatchewan Indian Nations top chief Lawrence Joseph, came within 800 votes of beating Conservative incumbent Rob Clarke when Joseph ran for the New Democrats in 2011.

Harper told supporters in Edmonton what Trudeau said about growing the economy "from the heart.

"What does that mean? I tell you what it means, it means Justin Trudeau is just not ready," Harper said Wednesday afternoon.

Speaking with reporters in Quebec, federal NDP Leader Tom Mulcair called Trudeau's comments a "unique perspective."

"I don't think you can grow the economy with touchy-feely slogans. I think it takes a solid plan," he said.

"Four-hundred thousand manufacturing jobs lost under Stephen Harper. We're not going to get those jobs back with touchy-feely slogans. We're going to get there with a tough plan to create jobs and grow the economy."

In Regina, Trudeau took aim primarily at Harper.

He said the Liberals would grow the economy in lockstep with environmental protection.

"You cannot, unlike what Mr. Harper proposes, make a choice between what's good for the economy and what's good for the environment. We have to do them both together."

He repeated promises that a Liberal government would focus on tax breaks for the middle class, and child benefits for people who need them the most, while asking the wealthy to pay more.

He said Liberals would remain committed to balancing the budget, but how long that would take would depend on how big of a "mess" the Conservatives have created.

"Stephen Harper's plan has failed because it's based on an error in judgment," he said.

"The Conservatives believe the way to grow the economy is to make wealthy people wealthier, to give the most to those who need it the least."

He cited last month's announcement of $3 billion in extra payments under the universal child care benefit.

"Why else would they send government cheques to millionaires just because they happen to have children?" said Trudeau.

Trudeau also criticized Mulcair, saying his idea to create a national minimum wage won't bring meaningful change.

"By national, they mean federally regulated industries, places like airlines and banks," said Trudeau. "The NDP's so-called national minimum wage wouldn't apply to over 99 per cent of everyone who makes minimum wage."

Also on Wednesday, Trudeau travelled to the northern Saskatchewan communities of La Ronge and Meadow Lake, meeting with local leaders.

Earlier this summer, La Ronge and several other communities were under threat and some were damaged from forest fires. Trudeau promised to hold a premiers conference to discuss climate change and how to increase resources to deal with its effects.