What can you grow on a green roof?

[LucidEnergy]

I know the soil depth is pretty shallow, but is there anything you can grow on a green roof? I assume most stuff that you could grow in a pot you could also grow on a green roof.

[St Rhenium]

It largely depends on the strength of the roof. The stronger the better, although this would mean sacrificing profitable areas of any large development, and as each tower can only support a set amount of weight, I think the developers would rather the weight was spent on an extra inhabitable floor than a great green roof (unfortunately). On a smaller building, I think you're looking mainly at flowers and pleasantries. What excites me the most is the thought of larger buildings that can support more weight going ahead and planting crops and even trees. That would be great.

[Zarostulus]

[quote author=St Rhenium link=topic=157.msg373#msg373 date=1448625385]
It largely depends on the strength of the roof. The stronger the better, although this would mean sacrificing profitable areas of any large development, and as each tower can only support a set amount of weight, I think the developers would rather the weight was spent on an extra inhabitable floor than a great green roof (unfortunately). On a smaller building, I think you're looking mainly at flowers and pleasantries. What excites me the most is the thought of larger buildings that can support more weight going ahead and planting crops and even trees. That would be great.
[/quote]
I don't think we'll see much of that for a very long time. For now, I think green roofs will be more limited to pleasantries, as you say.

[JamesH]

I'm not sure if soil depth is the main issue, but wouldn't roots potentially damage the underlying roof?  It really depends on just how deep the soil is to be able to say what you could grow.

[Zarostulus]

[quote author=JamesH link=topic=157.msg394#msg394 date=1448718354]
I'm not sure if soil depth is the main issue, but wouldn't roots potentially damage the underlying roof?  It really depends on just how deep the soil is to be able to say what you could grow.
[/quote]
The roofs must be designed with roots in mind, I'd imagine. There is probably a coating of some kind of hard, smooth surface underneath that is hard to crack and doesn't provide an entry points for water (freeze/thaw) or roots.