It’s important to remember the value of trees in our food-producing landscapes. I remember when Ecoschools first started, feeling like sometimes we were in conflict with the idea of planting more trees on school grounds, because we were thinking about the sun and the annual food plants that need 6-8 hours of it to produce. Other folks were thinking about the need for shade, to cool buildings and children. It just doesn’t seem right to have a conflict about this! We need shade AND sun. So the ideas around ecosystems and permaculture start to make sense in this context.
I think about the urban forest garden this way – there’s a canopy way up high (where the squirrels live and can safely get away from the dogs, only to dig up our seedlings another day). This layer produces the cooling and oxygenated air which we so need in Toronto summers.
Then there’s the understory, which supports fruit-bearing shrubs like elderberry, serviceberry, raspberry, red currant, and other perennials that do well in school gardens. Lots of small fruit – spreading the love.
Finally, on the sunny side of the trees and shrubs, we’ve got the beautiful black soil enriched by compost (and perhaps a leguminous tree, helping to make nitrogen available for the other plants!) in which we grow our sun-loving annuals.
What trees do we want? Well, permaculture ideas tell us that we want maximum yield for minimal input, and more than one benefit associated with each plant or planting. So, Sugar Maple provides shade and sap/syrup in spring. Redbud, (Cercis canadensis) a beautiful native Carolinian species, remains smallish so maybe a good landscape plant for urban areas, but I haven’t seen a lot of it around. Its seeds are edible, and it looks leguminous, so perhaps it is nitrogen-fixing. These are two of the species we’re planting from seed next week, in honour of International Biodiversity Day.
The shrub understory is of great interest to me, and to the birds. It’s a little bit hazardous for the plants to be loved by children, because the shrubs can’t always stand up to that tough love. Elderberry – Sambucus nigra – is not native but it’s way useful. The fruit is loaded with vitamins and anti-oxidants. Last year I made syrup and tincture from the berries, after eating my share fresh out of hand. All winter, whenever I felt a cold coming on, I had either syrup or tincture or both, and never got sick at all. Anyway, it’s an invasive type of plant coming up from the roots, which kind of makes up for the fact that the wood is weak and won’t fight back against kids pulling down the fruiting branches.
I have some extra elderberry cause as I mentioned it is rather invasive… you can let me know if you have a good spot for it and would like to have some. I also have extra seedlings of flowering raspberry, which is a lovely native shrub with a beautiful flower and wildly delicate fruit. The harvest will not make it as far as your kitchen, guaranteed. Let me know at firstname.lastname@example.org if you have a good school garden location for either of these plants.