My recent columns have focused on closer plantings, and on cherry cultivars that require lower chill hours or portions. This time the spotlight is on medium chill and high chill cherry cultivars.
Medium chill cultivars
Depending on the micro climate of your growing region there might be some medium chill cultivars that could produce reduced crops some years if not enough chill hours accumulate.
It can make a difference on the choice of rootstock that is used. For example, some dwarfing rootstocks being more precocious sometimes set more fruit under the same conditions. That can be checked with your nursery group supplier.
Weather data over a number of years is a useful way to determine the change over a decade, using either a weather station on your orchard or data available via the nearest Bureau of Meteorology station.
High chill cultivars
Similarly, should high chill cultivars not produce cherries at your location consistently, then replacing the same cultivar on a more precocious rootstock could be an option.
If not, a new block in a location that has a history of higher chill hours should be considered. It might have a higher elevation or just be a micro climate that has a different aspect that makes enough chill hours to be an improved proposition.
Useful resources
Cherry Growers of Australia, using the cherry levy, have two very useful documents that are of great assistance to growers tackling these issues.
Cherry cultivar selection: Chill hours and climate change. CY11010
And, Australian Cherry Production Guide 2017 Chill and heat requirements, from production to flowering.
These two documents have been produced by professionals for Australian conditions and growing regions and are useful tools for growers to assist sound decision making for future cherry orchards.
See this article in Tree Fruit Sept 2023
