Urban Trees from Seed

Updated: Aug 18

by Sunday Harrison


Trees provide shade and oxygen in our urban environment, but many trees fail for various reasons. Some are the wrong species in the wrong place, and some are simply reaching the end of their lives. Some have been victims of poor maintenance, and pest or disease problems. Our municipality and our school board require trees to be a few years old and a certain width diameter to be planted, but where do those trees come from? Many are raised from clones, so genetic diversity is lost. Only plants grown from seed will have a wider set of genes, making some individuals more pest- or disease-resistant than others. This is known as biodiversity within each species. Trees need nursery care for a few years, to get up to the size required by schools and our City.



Our project of growing urban trees from seed since 2017 has engaged thousands of school children, who have planted hundreds of successful seedlings. The species we’ve been most fond of growing is the Kentucky Coffeetree (photo, right), with its oversize pods and seeds, its ease of germination, and its fantastic story of being partnered with the Mastodon in ancient history. It is native to Turtle Island and carries the Anishaabemowin name Biizhou-aatig, which roughly translates as Big Cat Tree. One theory is that the name comes from the pod which looks like a big cat claw, but another perspective is that the tree had that name because big wild cats sat in it! Now, it is one of the more successful urban native trees (photo, below, students harvesting pods).



Ohemaa Boateng, our Program Manager, developed an online program (photo, left) so that students learning from home in 2020/21 could plant the seeds and grow their own trees. This was very popular as teachers were looking for hands-on activities for their students learning from home.


Teachers picked up kits curbside, and distributed them to their students! (photo, left). The pandemic has shown us how important both outdoor learning and hands-on learning are, so hopefully going forward our policy-makers will heed this call. Already, the Toronto District School Board produced new resources for school-ground outdoor education.


Other trees we planted from seed include PawPaw, (photo, right), the native fruiting tree that will produce fruit that “tastes like a cross between banana and mango”! These need to grow in a shady, wet but well-drained place, and are often planted in a thicket or at least in pairs, to ensure pollination. We planted Cedar/Nookomis Giizhik and although we have very low germination of this species, we do have a few seedlings to care for. Eric Davies, our tree-seed friend from University of Toronto, helped us plant acorns that he had collected from mature Toronto trees, and we now have many Red, White and Bur Oak seedlings to care for, known as Mitigomizh in Anishnaabemowin. They grew well in the unheated greenhouse in Regent Park (photo, right), watered with rainwater from the excellent rain-collection system installed there.


At this time, we have tree nurseries in three partner schools, and are planting a mix of tree species using special pots designed to inhibit root circling, another cause of tree death, where the roots circle in the pot and then eventually strangle the tree. The use of these special pots manufactured by RootMaker will ensure that when the seedlings are planted to their forever homes, they will have a healthy root system. But we have more tree seedlings than we can fit! We are bringing them to our market stall for sale (just to cover costs), and are also giving them away to good homes, so please contact us if you are able to provide a good location and the care they require. Email info@greenthumbsto.org, "Trees" in subject line.


Special thanks to the City of Toronto Urban Forestry Division and Eric Davies of Big Tree.


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