[Ianhhhhjikm]

Hi, I've got 10 containers full of used potato compost. I want to make a raised bed, using this compost,  to grow either parsnips or carrots. 
What do I need to add to this, nutrition wise,  considering that I will want to sow the seeds soon?

[Subversive_plot]

What you need to add will depend on the quality of the original compost, and what you added to it through the most recent crop.

Really the only way to know is to take a  soil sample and get specific recommendations from the lab for a specific crop.

[mumofstig]

I'd just add a handful of BF&B to each tub's contents before spreading it on the bed.

[Ianhhhhjikm]

Hi, thanks for your replies.
As it is a glorious day here,  I've been down the allotment and emptied the containers already!   I'll add the BF&B and rake it in. Will it be ok to sow carrots in this ? I think parsnips will be ok

[Nobbie]

Hi, thanks for your replies.
As it is a glorious day here,  I've been down the allotment and emptied the containers already!   I'll add the BF&B and rake it in. Will it be ok to sow carrots in this ? I think parsnips will be ok

Unless you usually have success sowing parsnips this early, I’d leave it a lot later until the soil has warmed up. April is plenty early enough to get a great crop. I don’t know why packets quote Feb for sowing parsnips and blame this for many people having problems with germination.

[rowlandwells]

we always use all our old compost's on the raised beds mix it with 6x on some beds and a Growmore mix on other beds  never had any probs reusing any spent compost we also found if there's grubs in the compost the birds soon polish them of 

[steven c]

sounds ideal use of old compost  after clearing one of our beds we sowed carrots [early nantes] in june
the germination was so good and good carrots that we now wait until much later to sow   good luck with what you choose'

[cc]

I am afraid I use it for tomatoes with some of my own compost at the bottom. I will not be doing it this year as i part dehydrate tomatoes and put them in oil with herbs. I have found I still have some from 2019. Enough is enough so carrots this year. Small troughs, so Parisian market and little fingers.