Article Provided by: Ariana Burgener, St. Williams team member.
Fall has finally arrived and with shorter days and chillier temperatures come the beautiful autumn colours. Now is a wonderful time of year to see the yellows, oranges, and vibrant reds that we at St. Williams Nursery & Ecology Centre look forward to each year. Among our many favourites for displaying bold fall colours is the Freeman’s Maple (Acer x freemanii).
Freeman Maple is a naturally occurring hybrid of Silver Maple (Acer saccharinum) and Red Maple (Acer rubrum) found throughout Southern Ontario. It has the stunning red autumn foliage of the Red Maple, and the fast growth of a Silver Maple. As a hybrid, it is hardier and easier to grow and it can tolerate poor site conditions better than a Red Maple would. Although the Acer x freemanii is often found naturally in wetland and swampy forests, it also does well planted in dry sites and tolerates urban settings well.
If you’re looking to add some fall colour to your yard, the Freeman’s Maple is an excellent choice. It’s a gorgeous shade tree and grows to be about 50 to 80 feet tall, growing to an oval shape – taller than it is wide. The root system is often shallow and does not exhibit aggressive growth, so it’s less likely to harm pipes or other city infrastructure.
For the best Fall impact, plant Freeman’s Maple next to shrubs with yellow fall foliage. Some excellent native species include Witch Hazel (Hamamelis virginiana) and Spice Bush (Lindera benzoin). This will give your yard a beautiful array of contrasting colour.
Why Do Leaves Turn Different Colours?
During fall, the days are shorter and the temperatures are cooler. This triggers plants to start shutting down for winter. As part of this process trees and leafy shrubs stop producing chlorophyll – the green pigmented molecule that absorbs light needed for photosynthesis. Once the tree stops producing chlorophyll, the cold weather helps to break down what remains. As the green pigment fades, other pigments in the leaves are revealed. Carotene – the yellow pigment found in carrots – is always present in leaves, but isn’t visible until chlorophyll has faded.
In addition to stopping production of chlorophyll, certain conditions within certain species can prompt the production of anthocyanin – the red pigment found in apple skins and grapes. The purpose of anthocyanin is somewhat debated, whether it is to help protect the now yellow leaf from sun damage, to help the tree retrieve as much sugar and nutrients from the leaves as possible, both, or something else entirely. Either way, the conditions for bright red leaves include cold but not freezing temperatures, bright sunny days, dry weather, and nutrient poor soil. These conditions increase the production of the red pigment, resulting in bright red foliage.