Kitchen Garden Forum

Anybody know anything about this? Growmore at 7-7-7 is usually just under £20 a bag, with its analysis this looks more economical but I don't understand the sulphur.

Dear Geoff,
this looks like a formula for acidifying the soil prior to planting or for spreading around plants which are acid lovers. It is NOT a general purpose fertilizer. I personally would choose a rose food as that will be better for general use. I get Sinclair or J Arthur Bowers rose food in 25kg bags and one does me for a season. Try looking in a country or agricultural store if there is one nearby; the prices will often be cheaper in them.
Regards Sally Wright

Not a chemist but reading carefully it looks like they're trying to reduce their use of chlorine, as Complex is chlorine free, using sulphated potassium whereas Maincrop (recommended for potatoes) has chlorated potassium.
The attached screenshot the last bulletpoint is illuminating.

£26 would scare me off without the benefits!

I'll have to see if there is any disadvantage to the sulphur content for brassicas that I usually give a high dose of Growmore. Their data sheets show application rates for all the brassicas. It is the cheapest source of nitrogen though I have realised if I use my preferred supplier of Gro-Well Fish,Blood and Bone is just cheaper than Growmore this year. If you correct the prices based on nitrogen content you get this table, i.e. if a formulation has 10% less nitrogen the cost inflates 10%:
Growmore 7:7:7 £20.65 /25Kg £20.65
FBB 5:5:6 £14.30 /25Kg £20.02 gives a bit extra potash
Rose 5:5:10 £21.75 /25Kg £30.45 quite a lot extra potash
YaraMila 12:11:18 £26.40 /25Kg £15.40 medium extra potash but a little less phosphorus

I asked the stockist.

Yara Complex is used extensively by champion NVS vegetable growers and is a good alternative to Growmore.