Dim wrote:of the choices available, my money is on soluble feed plus seaweed / iron (iassuming that you use the seaweed/iron every 2 weeks as a foliar feed during the growing season)
seaweed is good stuff .... but if you are foliar feeding, use spring water/ mineral water (39 pence gets you 2 litres of Clearview still springwater, or approx £1.20 gets you 5 litres of Asbeck spring water from Tesco)
some guys have reported probs using seaweed with hard tap water
(i'd also be inclined to add a handfull or two of vermicompost (worm humus) to the potting mixture if using the soluble)
I'm using the Seaweed as a root drench rather than a foliar spray. (Once a month as directed)