Oro-Medonte Horticultural Society Updates

— by Lynne Melnyk

I spent this spring in Italy on a garden tour with a group of Brits and one Aussie. As we stood at the entrance to one of the gardens, someone questioned the tree over our heads. There was a lot of head scratching and our guide who didn’t speak much English first said it was Acer (maple) and then ash. ‘It doesn’t look like ash to me,’ said one of the Brits. I said, ‘Actually, it looks like a Manitoba maple,’ and sure enough, I was right!

We have six native maples in Ontario, though Manitoba maple (Acer negundo) is native to Manitoba only and is considered invasive in Ontario. Manitoba maple has three leaflets rather than the lobed leaf that we recognize, hence the alternate names, boxwood elder and ash-leaved maple. This is a tree you don’t want in your garden—it seeds everywhere, grows quickly and is a weak tree whose branches break easily.

The other problematic maple is another non-native, Norway maple (Acer platanoides). Its dense canopy and shallow roots outcompete other natives and make it difficult for anything, including grass, to grow beneath it. It seeds everywhere and is also susceptible to a disease called tar spot, which can affect all maples and is very unsightly on Norway maples, but more subtle on native maples. Tar spot is mainly a cosmetic issue and doesn’t harm the tree. Unfortunately, Norway maples are still widely sold in most garden centres. You can identify a Norway maple by the white sap, if you pick a leaf.

The five native maples are our beloved sugar maples (Acer saccharum), plus silver (Acer saccharinum), red (Acer rubrum), moosewood (Acer pennsylvanicum), and freeman (Acer x freemanii). Black maple (Acer nigrum) may be a subspecies of sugar maples. Sugar, red and freeman cultivars have the best fall colour. Red maples can grow in wet conditions as well as normal soil and have showy red flowers in the spring. Don’t confuse them with the common Norway maple, ‘Royal Red’, which has maroon-red leaves all season. Moosewood maple has very large leaves, striped bark and is a smaller tree that can take shade.

NVK Nurseries, an Ontario wholesale nursery, lists 13 different cultivars of red maple and nine of sugar maple. There are six cultivars of freeman maple, which is a natural hybrid between the silver and red species, and one each of the species – silver, black and moosewood. Unfortunately, it also lists nine cultivars of Norway maple. 

The reason so many cultivars of our native maples are available at nursery centres is that they are a superior tree, suited to our climate, provide habitat for wildlife and the fall colour is spectacular. If space is an issue, there are also upright, columnar cultivars.

So, if you want a shade tree for your garden, please look at buying one of our native maples.

Join us on Monday, August 11 at the Oro-Medonte Community Centre when David St. Amand will take us on a journey with his presentation, Exploring the Lush Beauty of Irish Gardens. Add to the fun by decorating and wearing your fanciest garden hat with a touch of Irish flair – and don’t forget to wear green!

Looking ahead, mark your calendar for Monday, September 8, also at the Oro-Medonte Community Centre, where David Hawke will delve into the fascinating world of fungi with his talk, “FUNGI, everything You Need to Know About These Amazing Plants.” Additionally, don’t miss our flower show that evening, featuring breathtaking floral displays!

Love gardening? Become a member and stay connected – visit www.oromedontehorticulturalsociety.ca for details.