Can you please advise the name of a Yates product to provide iron for hydrangeas whose leaves are yellowing.

Thank you for contacting Yates. 

To help correct an iron deficiency, try 'Yates Leaf Green Iron Chelates'. It's a fast acting liquid that is used as a foliar spray - this helps deliver iron directly to the deficient leaves for faster result. Click here for more information on this product: https://www.yates.com.au/product/garden-fertilisers/speciality-fertilisers/yates-iron-chelate