Rose You know how cactuses like to pretend they are tough and don't whine for water every 3 minutes? I do. And that's what I like them for. It's been summer for quite some time now and what better place for your little spiky Desperados than your super hot, scorching, raw surface of your roof? That's it! Give these edgy(get it?) plants what they want.
In my opinion the prickly pear would look best on the roof because they resemble roof tiles. You just need to acquire enough to fill the area from your roof you want covered with green pointy features.
I'm not going to lie to you, succulents have been populating people's roofs for quite some time now. They are the usual choice for obvious reasons. But when you cover it with cacti you are now making sure kids will avoid losing frisbees there. Also who needs Santa?
The implementation does require some work though.
I will keep it simple:
1. It's good if you build or find...
...some plywood or whatever material you have raised beds that you need to waterproof. This is where you cacti go. Split them with ribs, so the soil won't fall off during windy days or earthquakes.
2. Next you need to set up...
...the soil. We suggest you first place some tar paper, then fabric soil, no fancy stuff needed here and some decomposed granite on top. The granite could vary from 1/4" to 3". Add up around 2 inches of it - this will prevent weeds. If you provide the roof with a better soil, the prickly pears might grow too much and you don't want your roof to collapse. Don't worry though - the proportions we are giving you here will do just fine and with no concern on your part.
3. Make sure you place the pads pointing...
...upwards or leaned towards the roof top, leaving small gaps in between them. This way they could collect rainwater easily. If you place them to look like shingles they might let the water slide over them(what shingles are meant for).
4. If you chose to plant your roof with succulents this would mean...
...the climate there is hot(and perhaps dry). It is good not to count entirely on rain in this case. For extra irrigation(just to make sure) you can add up a couple of micro sprays. It would be enough to sustain your prickly pears during long dry periods. They are really really tough and they can grow for weeks with very little watering so this is more of a precaution.
And your cactus roof is ready!
We leave to you the decision of how big it would be, but in case you can't decide for yourself - these are perfect fro small garages or sheds.
