My thumb -- not one of the hacked-up digits in the bad boy butcher knife incident -- is not green. Leastwise, not when it comes to indoor plants. Oh, I can grow a mean hydrangea or variegated boxwood out in my front yard as good as my neighbor. I suspect that's because God's in charge of the watering, not me. But give me an aloe or philodendron and hello plant-slaughter felony.

Which is really too bad because studies show that adding greenery to your indoor environment -- such as, oh, let's say a writing desk perhaps -- boosts your productivity. Cardiff University's School of Psychology published a study last week citing that adding plants to your work desk can increase productivity by 15%. Of course, there are other benefits as well:

• cleaner air
• better focus
• stress reduction (though I do take issue with this one since it totally stresses me out to see plant corpses littering my desktop)