Grist — A Beacon in the Smog

• Log In or Register (Why?)

• Why register?
  As a registered user, you can control whose comments you see, follow your favorite authors, and generally play god in your own little Grist kingdom. What’s not to love?

• Grist by Email
• Donate
• About
• Pressroom
• Contact

• Top Stories
• Politics
• Climate & Energy
• Food
• Business
• Living Green
• Placemaking

• 

  Obama administration may (finally) offer greenhouse-gas targets 3 Posted 16 hours, 10 minutes ago

• This Friday, don’t just Buy Nothing—use nothing! 1 Posted 18 hours, 40 minutes ago

• Grist Exclusive: Will Whole Foods’ new mobile slaughterhouses squeeze small farmers? 6 Posted 3 days, 11 hours ago

• Politics
• Climate & Energy
• Food
• Business
• Living Green
• Placemaking
• More

• Gardener on the Roof

  Umbra on green roofs 4

  Posted 3 years, 11 months ago

©2009. Grist Magazine, Inc. All rights reserved. Gloom and doom with a sense of humor®.

Sections

• Politics
• Climate & Energy
• Food
• Business
• Living Green
• Placemaking

Columns

• Ask Umbra
• The Bottom Line
• Victual Reality
• Farmer's Daughter
• Checkout Line
• Green State

The Fine Print

• Privacy Policy
• Terms of Use
• Trademarks
• Contact Us
• Jobs at Grist
• Advertising