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Seed Compost & Potting Compost
NewBoy2
Posts: 1,813
This is my Stupid Question No 8
I can hear the groans now 
On a packet of Afro Kale seeds from Unwins it says start off in seed compost and then transfer to potting compost when the seedlings are big enough
If I should be buying 2 different bags of compost from the GC what should I look for at point of purchase
Everyone is just trying to be Happy.....So lets help Them.
0
Posts
I think it has to do with the amount of nutrients in the compost.Seed compost has very little and is used just to get things started as the seed has its own nutrients.The next compost has nutrients to help the seedlings grow on.
Hope that helps!
Seed compost has fewer nutrients and is of a finer consistency than potting compost and often has sand and/or vermiculite added. It is only really for germinating seeds and the fine texture makes it easy to prick out seedlings. Having said that, I sieve MPC and add sharp sand and fine grade perlite or vermiculte and use that for starting off seeds without any trouble. Some folk just use MPC as-is and get on just fine. Personally, I would recommend sieving it as if roots grow into big lumps of compost, they will almost certainly be damaged when you prick out the seedlings.
Seed compost is more expensive than the other and I've found that it still has big pieces in it. I use MPC. With JI in it. That works well for me.
I do the same as Bob, MPC with some grit, but as I mainly sow in spring, it's less of a factor. I often just use multi purpose alone. it also depends what you're growing - some things are more forgiving.
Seed compost is more useful if you sow things in autumn. Anything more nutritious will create leggy seedlings you have to overwinter, and that's more of a problem.
I live in west central Scotland - not where that photo is...