Frost risk – manage wheat variety and sowing time

Page last updated: Friday, 20 April 2018 - 10:31am

Please note: This content may be out of date and is currently under review.

Use Flower Power to support your decisions

Our online tool, FlowerPower predicts when wheat varieties flower in Western Australia while also displaying frost and heat risk. Understanding flowering times of different varieties and the risk of frost or heat stress in your location can be used to decide on a variety and the most appropriate sowing date.

Flower Power can also be used in conjunction with Table 1 which provides the optimum flowering window for yield. Note: an asterisk (*) indicates that a damaging frost may occur in the first half of the window for some of the regions.

Table 1 The optimum wheat flowering window for locations across the Western Australian Wheatbelt
North-east North-west Eastern Central* Lakes* Great Southern South Coast
25 August - 15 September 3 September - 23 September 1 September - 20 September 5 September - 25 September 1 September - 20 September 16 September - 6 October 3 September - 2 October


The science behind flowering

The major factors affecting plant growth and time to flowing are vernalisation (exposure to cold), photoperiod (daylength) and thermal time (accumulated temperature). This means that a two-week delay in sowing will not result in an equal delay in flowering. The exact flowering will still vary from season to season, depending on sowing date and local temperatures.