Germinal has asked customers who have purchased its wildflower mixes to return the stock where possible.
A spokesperson for the company stated: "Germinal is recalling all wildflower mixes by contacting our merchant customers and asking them to return any wildflower seed they have in stock.
"Any customers who have purchased a wildflower mix are also being asked to return it to the point of sale for a refund."
The company has reiterated to the Irish Farmers Journal that the matter is being taken very seriously and they are trying to get as much seed returned as possible.
Where seed has already been planted, the company will have representatives visit sites on request to inspect for blackgrass.
On Tuesday, 18 May, Germinal confirmed that blackgrass had been found in a batch of wildlfower seeds which had been grown in England and that sales of the seeds had been ceased.
What to do if blackgrass is present
Blackgrass plants should not be allowed go to seed and should be destroyed once spotted. The only herbicide which offers 100% control of the weed is glyphosate.