It's Blossom Time!

by Ken Slingerland, Tender Fruit and Grape Specialist, Ontario Ministry of Agriculture, Food and Rural Affairs

Just how early are the tender fruit blossoms this year? Each year we check our indicator tree, Prunus davidiana located at the Department of Plant Agriculture, University of Guelph’s research “Vic Farm” at Vineland Station for the blossom stage.

Vineland Station has been recording the blossom date for Prunus davidiana since 1954.  Prunus davidiana is a species of stone fruits that is closely related to the commercial peach which is Prunus persica. Both species are native to China.  The indicator trees at Vineland are actually a cross between an old commercial peach cultivar, Halehaven, and Prunus davidiana made in 1939 identified as V39071.  The tree has been used in the peach breeding program in earlier years because the tree showed some resistance to perennial peach canker.

First bloom was recorded on April 3 this year as temperatures were in the high 20’s across the region over the Easter weekend April 2nd to the 5th.  The warmest temperature at Vineland Station was 26.5°C recorded on April 3rd. Full bloom was observed on April 6th, one day later than the record set in 1998.

What does this all mean? Prunus davidiana bloomed 18 days ahead of normal this spring.  So we can likely expect that commercial peach cultivars like Redhaven, which has an average blossom date of May 11th, should be blooming 18 days earlier on April 23rd.

On the positive side, an earlier bloom usually means the fruit will ripen earlier in the season so consumers will be able to enjoy fresh local fruit earlier. On the down side, there is the risk of spring frost and losing part of the crop. A handful of tender fruit growers have invested in wind machines to blend the warm and cold air to reduce the risk of frost, similar to many grape growers who protect their crop with wind machines. But for most tender fruit growers, there could be some nervous nights ahead until the last risk of frost which is usually around mid May for Niagara growers.

The Niagara Peninsula is home to approximately 11,000 acres of tender fruit, approximately 90% of all tender fruit in the province. Lake Ontario plays a big role in moderating the temperature here in the peninsula and typically holds back plant development and bloom closest to the Lake. Orchards located near the escarpment have less moderating affect so they will always bloom first. At the time of writing this message, tender fruit blossoms at Vineland Station are still 7 to 10 days away, while Apricots and Japanese (yellow) plums are just starting to bloom in the St. Davids and Queenston area next to the escarpment.

A lot can happen in the next two weeks as temperatures are predicted to be in the mid teens. A cold spell just above freezing could put everything on hold but as I look out my office window, I think it is safe to say we are going to have an early bloom this year.

FYI – the last time we had a bloom this early in 1998, we had one of the nicest peach crops and a vintage year for grapes. Enjoy the spring!