Tuesday, June 1, 2010

Late Spring Rooftop Pictures

It's been unseasonably warm in the past few weeks. The rapini (or is that rapa) has gone to seed. It's nice to see that my cedar SIPs are working properly.

My test run of peat based potting mix (foreground SIPs) vs. coir (at top) is still going strong.

The tomatoes are off to a good start. Despite our tomato seedling glitch, I have tomatoes in 8 SIPs this year, all growing varieties I bought from Genesis Growers at Green City Market.

You'll notice that I've skipped the plastic bag mulch/UV cover and am using ordinary pine bark mulch. After seeing that the SIP used by the Montreal Rooftop Garden program uses wood mulch in place of plastic (as detailed in the instruction manual contained in a pdf found at this link), I decided it would be worth breaking with our normal procedure in order to eliminate some plastic. That discovery also led to my next change.

Earlier this spring, I surrounded my rubbermaid tub SIPs with long panels made out of 2x2 lumber, UV resistant brown tarps, and cedar fencing boards. There are a several advantages: I don't have to use a plastic bag to protect the tubs from UV; I can now roll a length of tarp over the top of a row of planters at the end of the growing season, offering protection against the winter elements; best of all it doesn't look like my rooftop is littered with plastic bags that are sprouting plants.

After stopping by to say hello and take some pics, H2 headed home with her herb starts.


Unknown said...

I have been looking for instructions, in order to plan converting all of my garden pots next year. Thanks for the link, though it looks like the link to the instruction manual may have changed. I found it here: http://rooftopgardens.ca/files/manual%202009%20web.pdf

Debbie said...

Amazing! Bruce your greens and planters look great. I was just talking to a friend about using coffee grounds as mulch and am thinking about trying it. Any thoughts?

Bruce said...

Brian -

Thanks for catching my bad link. I think it's fixed now.

Debbie -

I've used coffee grounds in my compost pile before. I don't know if you want to use them directly as mulch. This link claims that under the direct sun, the uncomposted grounds can harden into a crust that will repel water. Not sure how likely that is, I've never tried it. If you do, let us know how it turns out.

I do know that uncomposted coffee grounds are fairly acidic. As is peat based potting mix. I wonder if raw grounds as mulch would push the ph of your mix even lower?

Mute Dog said...

Your blog always makes me wish I didn't have a peaked roof on my house. ;)

Anonymous said...

Hi, very nice rooftop garden you have! I have a question: why do you need to protect your tubs from the uv? thanks, Salla

Bruce said...

Hi Salla,

Good question.

Rubbermaid tubs and ordinary 5 gallon buckets will deteriorate/crack in a couple of years if you don't protect them from the sun. By wrapping them in the panels of brown tarp, I'm hoping to extend their life.

Plastic that's meant to be used outside, like the official Earthbox, is modified with additives to make it more resistant to the sun's UV rays.

Thanks for the kind words about the blog.

H2 said...

We've used food-grade buckets for years without a crack, just FYI.

Bruce said...

Good point H2.

I'd read about problems with the rubbermaid tubs cracking in the sun, so did some (unnecessary?) preventative construction.