Colours have peaked in most parts of Canada
Catch 'em before they're gone!
The Fall colour season is coming to an end. If you hurry, you may be able to see some final glimpses of those vibrant reds, oranges and yellows.
Most sections of northern Ontario are well past peak, and most are now at a 90-100 per cent leaf fall. It's a similar situation in the Ottawa region, Owen Sound and Hockley Valley.
So where can you find the best foliage at this time?
There are still pockets of colour in the south Kawartha Lakes region, as well as around Bayfield and Goderich. The colour is now past peak in the Niagara region, but bright red, orange, yellow and golds continue to dominate. Metro Toronto is offering some nice pockets of colour at this time, as well.
Ontario's Algonquin Park in the Fall
Why do the leaves change colour?
“Temperature plays a factor in the coloration of trees, but the most important factor is called the photo period, or the length of daylight,” horticulturalist Bob Osbourne of Cornhill, NB told The Weather Network.
“The shortening of the number of hours of daylight is the trigger for trees to start shutting down. A cork-like layer forms between the leaf stem and the branch, which will eventually fall off and it also protects the tree from any kind of fungal or bacterial infection. As it shuts down, it begins to stop water and nutrients from coming into the leaf and the chlorophyll dies.”
Osbourne says this phenomenon is what allows us to see the various pigments that have been there all along, but are only visible now because of the lack of green.
Stress is a big factor in coloration.
It may be a matter of too much or too little water, or other nutritional factors. You can spot a stressed tree by its leaves, which change color before the others.
Tree stress can affect whether the fall show will be sensational or not. Things like drought, extreme temperatures and air pollution can make the leaves dull.
“The most famous of all the trees is the Sugar Maple,” adds Osbourne, “with its combination of orange, yellow, and sometimes red. One of the most spectacular of the trees is the native Red Maple with its vivid red color. These are the trees we most associate with fall.”
Warm temperatures and extreme drought conditions have had an impact on trees across the United States. As a result, trees lacking water will show symptoms called leaf scorch, the browning of leaves.