Marijuana plants grow wild in Japanese prison

Well, if you're going to wind up stuck in prison, it may as well be this one:

A Japanese prison is scrambling to eradicate marijuana plants that keep sprouting up on its exercise ground, officials said Tuesday.

The marijuana plants started sprouting at Abashiri Prison on Japan's northernmost island of Hokkaido about a year ago, said prison official Takeshi Okamura. He said officials plucked out as many as 300 marijuana plants and treated the ground last year, but several more sprouted again this year....

Local botanical experts concluded the marijuana seeds were inadvertently brought in with the soil used for the exercise ground, Okamura said.

The weird thing here is that officials learned about the pot from the reports of prisoners. I'm not entirely clear on what advantage you'd gain from reporting wild marijuana plants to the people who are keeping you in prison; come to think of it, I don't really need to know...