Last years compost

[ghostbreeder]

I am keeping notes of everything that I sow this year (mostly because somebody gave me a nice notebook for christmas). I've gone as far as noting when I used the remains of the compost from last year rather than the fresh bag from this year (both gro-sure seed and cutting). I'd say that this years compost is roughly 75% more succesful than last years. Does compost go off?

[Potstubsdustbins]

Not usually, have you added nutrition to the old compost such as 7-7-7 grow more?

[ESBkevin]

No not if it's bagged, if it's exposesd and on the soil it can leach out the nutrients.
Adding last years leafmould (or even the year befores) can re-mineralise older weaker compost. Seeds generally don't need nutrient rich compost for the starter weeks.

[Penellype]

For seeds I prefer to use new compost, mainly because it has been sterilized. This allows the seedlings to get a good start with less danger from fungi such as damping off etc. Last year's compost will be full of life, some of which may not be all that good for your seedlings. It is fine for older plants, which are big enough to cope, although you will need to add nutrients as last year's plants will have used most of them up.

[spamvindaloo]

I might be wrong but I read the original post to mean leftover compost that was bought last year, not compost that was actually used last year.... perhaps the OP will come back and clarify.

[Penellype]

You could be right, in which case it would be fine.

[elleme]

I re-used some old compost earlier this year and seedings seemed more prone to damping off, plus I found little white worms in the soil which I suspect were eating the seedling roots. So not a great start. The bag was hanging around open in the greenhouse all winter so that may not have helped.