Gartman: Going for the Copper

Is now really a good time to add commodities to your portfolio?

That depends, according to Dennis Gartman, founder of the Gartman Letter. His advice: consider copper.

Related Special Report:

The economy is beginning to show some "green shoots," adds Gartner, including this morning's Wells Fargo earnings report. And that makes copper and aluminum commodities worth buying.

At the same time, Gartman advises investors avoid grains. There's way too much uncertainty, like what's going to be planted and whether the weather will cooperate.

Additionally, while Gartman says he's been bullish on gold for a while, it's probably hit its high, for now.

So if you're looking at commodities, says Gartman, keep it simple, with aluminum and copper—two things that have fallen precipitously over the last year.

If Gartman's advice sounds like confidence in the government's economic stimulus package, it is. "I'm actually quite optimistic about what the economy's going to do," he says. It might be six to nine months before things start to break, but he advises investors need to get involved in commodities before that happens.

Gartman says he got "very lucky" by buying Alcoa, Southern Copper and Freeport-Mcmoran near their respective lows. "I looked around and said, 'What is the simple thing? I'm a simple guy,'" he says, and it was "the stuff that if you drop it on your foot, it hurt."

And Gartman's not planning to get out any time soon. "The copper stocks have really now just gotten started."

As for oil, Gartman believes it will stick around $52 for a while. There's more than ample supply of oil around. "It may go higher," he says, "but it will do so without me."

So is it possible there could be an early frost that kills the green shoots? Sure, says Gartman, but there are too many signs—lumber going up, copper and alumininum going up. All these things, he says, seem to indicate "the frost is behind us."

More from CNBC Special Reports: