Heavy rain in February ruined crops around the country, leading arable farmers to describe it as the season from hell.
Edmonds said the weather meant yields in the South Island had been significantly impacted.
"With the reduced supply available in market we haven't been able to source enough New Zealand grown wheat for our Edmonds flour," a company spokesperson said.
"In order to ensure Kiwis have access to an ongoing supply of high quality flour, we have had to urgently source wheat from Australia, which will continue to be milled and packed in New Zealand."
Edmonds packaging states the company only uses New Zealand wheat so it will be updated to reflect the change.
"Due to supply chain constraints, we will have to use wheat from Australia before the new packaging is available, so will be identifying this product by printing 'Made from Australian Wheat' under the Best Before code of the product.
"Edmonds continues to be committed to delivering Kiwi bakers high quality flour to ensure best baking results."
