Vertical Gardens Again

The Economist has a good piece on vertical gardens, which ends thus:

Rooftop farming may not be able to compete with other suppliers in a global market unless people are prepared to pay a premium for fresh, local food, says Mr Head. And it is much less glamorous than the grand vision of crops being produced in soaring green towers of glass. But, for the time being, this more down-to-earth approach is much more realistic than the sci-fi dream of fields in the sky.

Reihan Salam who is often a conservative I can listen to is duped  by Valcent.