Posted: 17/04/2013 at 18:29
Get quality stuff for seeds - just think of the seed cost and your time, and the disappointment if your sowings fail, and the cost of late replacement plant purchases from your garden centre! False economy to buy seed compost on price.
On the other hand, if you are looking at a potting on / bedding plant compost then anything will do I reckon. Any fertilizer will have washed through in 6 weeks anyway and you should then use MiracleGro or the like. All the better if it has moisture retaining beads - saves on watering time, but if not you can buy the beads and add them yourself.
And if you are looking for a compost for a shrub like a wisteria then use John Innes No3 (Not No 1 or no 2) - packed with long lasting nutrients that don't wash out. Don't be fooled by cheaper multipurpose composts 'enriched with John Innes', it might only be 5% enriched and it won't tell you how much on the packaging.