Wood decking over composite roof liner. EarthBoxes haven't arrived yet.
In the past I’ve gardened ground-direct, in raised beds, or in standard planters. This year, because of the unique challenges of growing on a Chicago roof top, I chose self-irrigated planters (SIPs). Specifically, EarthBox brand.
EarthBoxes are popular in Chicago for many practical reasons, but also because they have received a lot of attention from local celeb chef and roof top gardener Rick Bayless. The Inside Urban Green blog posted an article several years ago about Rick’s rooftop.
Here are some other reason’s they seem practical and popular:
- Ideal size 29″L x 14″W x 11″H
- Easy to use, all-in-one, “just add water” kind of setup
- Aesthetically pleasing: basic rectangle in 3 color choices
- Good choice for hot spots due to self-contained irrigation
- Can be brought indoors for year round gardening
- Made of recyclable food-grade plastic
- Have a strong resale value on eBay or Craig’sList
That last point can be argued but even after reading a lot of ingenious garden blogs, I still found EarthBoxes to be a solid choice. Even DIYers end up spending money on plastic buckets and fittings and tubing and trellises. And I’m not so sure the hardware buckets and tubing are made out of safe plastic. I’m all for DIY projects, so if nothing else they may save a few bucks and are a fun project. But I’m also all for supporting small businesses doing big things like EarthBox.
I started out by purchasing 10 EarthBoxes so I got a bulk discount of $27/box. After pricing planters in local garden centers and other SIPs online, that’s still a pretty good price. Also, it’s pretty clear they are popular enough that I could easily resell them if I wanted to.
The visual appeal, I have to admit, was a big factor for us. I grew up in the woods of Northern Michigan on a small hobby farm so the concept of aesthetics and gardening requires some swallowing of that rugged pride. But we want our roof to be an entertainment and relaxation area, so the uniform look of the boxes seems clean and unobtrusive (unless you’re into that blaze-orange Home Depot bucket look!) We want the focus to be on the beautiful plants not on the planters. Ok, the truth is, if I make our rooftop look sloppy I probably wouldn’t be allowed to garden next year. *smile*
The EarthBox website explains that each box holds approx. 2 cu. ft. of potting media. I spoke with a salesperson at Downtown Home & Garden Center in Ann Arbor, MI who highly endorses EarthBoxes and claims they only take 1.5 cu. feet. So that’s less than 80 pounds of wet weight per box. The Garden Center sold 2.0 cu. ft. bags of Sunrise organic potting mix in the media ratio that EarthBox suggests so that’s what I chose. I’ll be amending with dolomite and organic fertilizer.
I also spoke with the guys at Green Thumb Garden Center in Ferndale, MI who suggest I supplement my plant feeding with silica. They believe it’s a natural way for plants to add their own extra structure to their stems for situations like rooftops in Chicago where wind is a huge factor. EarthBox sells a trellis system but that would have made my purchase substantially more expensive. For support I’ll do DIY trellis and wind breaks this year and try the silica. Clearly this year will be a big experiment, but I suppose with gardening every year is.
Rooftop view looking East towards the city.