When talking about green roofs, we often think of those tough little sedum varieties planted in 4 inches of engineered, lightweight soil. When we talk about outdoor commercial roof farming, leafy veggies that grow quickly and sell for a lot, like mesclun, come to mind. But last night at the Brooklyn Brainery, we were talking about apple pie in the sky!
Mike Biltonen, the grower from Red Jacket Orchards, traveled five hours down from the Finger Lakes of New York to talk to a roomful of curious urbanites about planting fruit trees in the back yard (who has a backyard in Manhattan?) or on the roof. Mike knows his fruit trees. He has two degrees in horticulture and more than a couple of decades of experience, literally out in the field. He is so passionate about growing fruit trees that he spoke nonstop for 90 minutes, and that was really only an introduction.
Mike explained the three basics to keep them apples commin’: Site selection (lots of natural sunlight), pest management (bugs, arachnids, mites – you name it, they want to eat your fruit as much as you do) and fertilizing the soil for healthy trees (kitchen scraps take care of most of it except for the all-important nitrogen).
He touched on the enormous variety of fruit trees available, dwarf trees that will fit on the roof, different rootstocks, and even tried to convince his audience that, with a little practice, they could accomplish grafting to grow more than one variety of apple on a single tree. By the way, all his sage advice works with peaches, plums, cherries, pears, figs, etc., but he advised that, for the best chance of success, beginners start with disease-resistant apple varieties.
If you have a full-sunlight roof, a 55-gallon barrel cut in half, some good soil, a bare root tree in early spring time and some excellent fortune, you can have apples as soon as that summer. Or, Mike advised, if you want to ensure the longer-term health of the tree, skip the apple harvest the first year. After the tree blossoms that first summer and you’ve enjoyed the beautiful buds for a while, break off the flowers, which allows all the nutrients to fortify the young tree. Then the following summer when you LOOK UP to your well-adjusted, strong apple tree, you can harvest your own fruit and make a roof-grown apple pie. Bon appetit!