Zelkova, Hackberry or Honeylocust?

(Question)

Hello.
I am having trouble deciding which tree to plant in my backyard. The width of my property is 55 feet, and I have plenty of open space in my backyard to plant a big tree.
I’m very indecisive and with all my research, I think I have it narrowed down to 3 trees – Japanese Zelkova (Green Vase), Hackberry, or Sunburst or Skyline Honeylocust.
I love the appearance of elm trees, and know that Zelkova resembles elms without many of the diseases or problems. Hackberry trees are similar, but not as nice or as big. I love the look of skyline honeylocusts, but I have heard they attract a lot of bees, are pain to clean up and can have a lot of root runners or surface roots, which I don’t want to deal with.
Which tree do you recommend? Do you think Zelkovas, although not native to Toronto, would thrive well? I live in central Etobicoke.

(Answer)

You’ve obviously done your research!  All of your choices have much to recommend them.

Skyline Honeylocusts are a great choice, from their lovely open form, to the ease of raking in the fall (their leaves fall early and crumble easily into the earth).  Their fragrant flowers do attract insect pollinators but the canopy will soon be quite high on these fast growers.  Surface roots can be a problem with many fast growing tree species, but many older trees also produce roots at the surface of the soil.  Surface roots shouldn’t be covered by a layer of soil or grass, but you could obscure them by planting a ground cover such as Pachysandra.

Celtis occidentalis, the Hackberry, is also a good choice, a workhorse of a tree.  One writer, Arthur Lee Jacobson, writing in Trees of Seattle, puts it this way:  “Celtis are often rugged, handsome, deep-rooted shade trees afflicted by few serious pests. Lacking flamboyance and romantic associations, hackberries are like cinder blocks: eminently useful but stigmatized by default”.  In other words, the Hackberry is reliable but it may not steal the show.

Zelkova serrata “Green Vase” is a very beautiful specimen tree, with its spectacular fall show, and although not native, appears to thrive very well in the city.   An earlier Toronto Master Gardener post mentions the introduction of a couple of Zelkova cultivars (“Green Vase” being one of them) at the Royal Botanical Gardens in Burlington as replacements for ash trees.  It may be worth making a visit to have a look at them before you make a final decision.

The City of Toronto recommends all three of your choices as good trees for Toronto in terms of their drought tolerance.

You have a tough (but fun) decision ahead of you, and at the risk of adding to your list, here is a previous Toronto Master Gardeners post that provides advice on large tree specimens to replace an ash tree: https://www.torontomastergardeners.ca/askagardener/need-large-tree-advice/ .  Its recommendations would also be interesting choices for your garden.

And finally, here is a guide to planting a tree that contains plenty of useful information: https://www.torontomastergardeners.ca/index.php/factsheet/planting-a-tree-a-toronto-master-gardeners-guide/