What Does the Frost Damage Mean for Trees in Toronto?
Jun 7th, 2012 by Paul Stewart, Metcalf Foundation Intern
As much as we all enjoyed the unseasonably warm weather that occurred in March, many of you may have heard that Ontario’s tender fruit farmers are reeling from it. The warm weather brought fruit blossoms in Ontario’s orchards out a full month earlier than normal. This meant that the blossoms were left open to frost damage for a longer period than normal. In late April a killing frost blew through Ontario with temperatures as low as minus seven degrees celsius. This has left Ontario Apple Growers claiming an eighty percent crop loss.
While this has been a devastating loss for many farmers across Ontario, some are saying it is too early to tell whether such stunning damage occurred. Some farmers believe there are still enough blossoms left unharmed on their apple trees to provide a normal harvest. Others are saying that for apples and pears you need to wait until September to determine what the harvest will look like.
What does it all mean for Not Far From The Tree and all the fruit trees in the city? First off, it’s probably too soon to say. While frost does damage the blossoms on trees it doesn’t always mean a total loss of harvest. Often not all the fruit on the tree is lost. Most of the damage occurs at the top of the tree and on the outside blossoms, while the fruit towards the trunk is left unharmed. Sometimes the fruit is just damaged causing frost scarring or ridging, which leaves the apples looking like little pumpkins. While these fruits may be left a little ugly and deformed they will still be excellent for the delicious cider and yummy preserves that many people like to process their harvest into.
It will also be interesting to witness how Toronto’s trees react to a late frost compared to Ontario’s rural farmers. Toronto’s trees have some unique things going for them in terms of protection from frost. Toronto is close to a large body of water; typically this is a benefit when trying to avoid frost damage. Whether we like it or not, and despite all of its negative impacts, Toronto is an urban heat island. The urban heat island effect can produce a difference in temperatures ranging from one to six degrees Celsius. This range could be enough to offset the ill effects of a killing frost.
What do you think? If you have a fruit tree in your backyard or somewhere in your neighborhood, check it out and let us know if you see any apparent damage.
Hi folks,
You picked apples from our tree last year for the first time – which was terrific. We looked forward to having you come again this fall – but we’ve had no blossoms on the tree this spring – well, we saw exactly one tiny pink bud, but that’s all. We assumed that was the result of the weird weather, but it sounds as if other trees bloomed and then the blooms were damaged, whereas with us, there were no blooms to damage.
Any thoughts on that?
Thanks.
cheers,
Susan
Hi Susan,
That does sound odd. I know some apples are biennials so maybe this is the trees off year. How many years have you had the tree for? Has it done this before? Tree’s can also be effected by heavy pruning or fertilizing which will make the tree focus on vegetative growth rather than flowering. Did you do either of these last fall? It does sound like something different than the frost. Hopefully that solitary “tiny pink bud” makes a very tasty apple!
Best, Paul
Hi Paul,
The tree has been in the front of our house for 11 years; we moved it (as a small tree – maybe 6 feet tall) from the back where it had very poor soil, and it seems to have thrived in the front. Last year was its best year so far for both blossoms and fruit; before that it had some good years and some poor, but never no blossoms at all! We did no heavy pruning or fertilizing last fall; only picked the huge harvest of apples. One other oddity I just noticed this afternoon as I was weeding in the front garden – the apple tree is sending up a whole lot of little shoots, just a few inches from the base of the tree. Any idea what that might mean?
Thanks…
cheers,
Susan
Hi Susan,
Those little shoots that are coming up are suckers. It’s important to cut these back just below soil level. These suckers tend to drain energy from the tree because the energy is going into the new vegetative growth rather than fruit production. It’s possible that the energy going into the sucker growth prevented the blossoms from happening. Suckers often start to grow in response to drought, winter injury or salt spray. It was a very dry winter and spring so I wonder if that could be the case, otherwise is it possible that city de-icer would run off onto the front lawn? As I am doing brief research for this issue it is inspiring me to attend some sort of school of agrology.
Best, Paul