Growsure slow release plant food for potatoes in pots ? NPK 12-7-19 any good ?

[AJ WEBB]

I saw this today and thought it looked good for my needs, is this suitable for potato growing in 30 ltr pots or should I use some thing else ??

[Spunky]

That looks very good how much was it?

[AJ WEBB]

£6.99 for 2KG

[Potstubsdustbins]

I use something very similar same NPK from Marshalls. Though I must admit I still give my second early and main crop supplementary feed.