Jim Cramer's Portfolios of the Week

Updated from 7:13 a.m. EDT

Jim Cramer returned to his computer and the studio this week, well-rested from a much-deserved vacation. He wasted little time and jumped right back into the markets to uncover some key investment trends.

Recently, Cramer found opportunity in green stocks, defensive stocks and agricultural and natural gas stocks.

Here are some Cramer highlights from over the past week as aggregated from his "Mad Money" TV show, the "Stop Trading!" segment on CNBC and his RealMoney blog posts (these blog post links require a RealMoney subscription).

Cramer's 8 Green Stocks Portfolio: Cramer took a fresh look at his green stocks portfolio. On Monday's "Mad Money" show, Cramer told viewers: "I got Tetra Tech (TTEK Quote) wrong, but now it's actually becoming right."Cramer's 8 Green Stocks Portfolio includes First Solar (FSLR Quote) among others.

Cramer's Defensive Stocks: Cramer thinks it's wrong that investors aren't buying defensive when oil spikes higher. In an April 22 blog post, he wrote: "I find that pretty amazing. Higher oil prices mean a slowdown in the economy, which means buy drugs and foods, or at least drugs." Cramer's Defensive Stocks include names like Philip Morris (PM Quote) and Eli Lilly (LLY Quote) among others.

Cramer's Insurance Stock Picks: Cramer sees opportunity in the insurance sector after Liberty Mutual bought Safeco (SAF Quote) for more than $6 billion. On Wednesday's "Stop Trading!" segment, Cramer told viewers: "The Street has missed out on the insurance game. There were 12 holds and four sells on Safeco." Cramer's Insurance Stock Picks include Chubb (CB Quote) and Prudential (PRU Quote) among others.

Cramer's Ag and Natural Gas Stock Picks: Cramer feels the chances for crude oil sliding back to $100 a barrel are slim. In an April 18 blog post, he wrote: "Do I think oil can retreat to $110? Yes. But you will have to buy these stocks if it does, and it will feel horrible when you do. As horrible as it has every other time that oil has dropped and everyone calls the big oil move over!" Cramer's Ag and Natural Gas Stock Picks include Potash (POT Quote) among others.