Can I use old compost to earth up potatoes?

[Wonky]

As the title asks really. I have planted potatoes in containers / potato bags. These have started sprouting and leaves are up through the new compost they have been planted in.

I have two large bags of compost emptied from my planters from last year. Last year I grew french beans, carrots, basil and lettuce in this compost. I have no idea what I can do with this and thought it might be good to use for earthing up? Any advice would be greatly appreciated.

[Ian White]

I dont see why not but i am sure someone with a better idea than me will be along soon to tell you

All the best,Ian

[Nicos]

I'd use it.
I'd have thought that you'd only really need to steer clear of compost which had grown tomatoes and aubergines in previously.

[Mikey]

If you have it add some potash, it helps keep the pots clean (from slugs and snails).

[Wonky]

Excellent! Thanks for the quick replies.

[Flummery]

Yep, beef it up with a bit of feed. I've even used old tomato compost - naughty (but I'm nice really) but I wouldn't have done if the toms had shown any sign of disease.

[Potstubsdustbins]

Sieved a load of old compost today mixed in some BFB and used it to earth up my spuds.

You can reuse old compost for most things provided you add nutrients to the mix.

Colin

[Kristen]

I put granular Potato Fertilizer in by bags when I plant them, and as such I don't feel the need to use fresh compost (containing more nutrients) when I earth them up. I reckon most of the feeding will be going on at the bottom of the bag (mine have 4" of manure at the bottom)

So i reckon pretty much anything will do! although avoiding anything diseased last year would be prudent, and anything that had Potatoes / Tomatoes / their sibblings would be prudent too (apart from disease, they will have selectively stripped nutrients that this year's crop will also be after - notwithstanding the feed you are giving - similar to the reasons for crop rotation in the open)

[Herbsandveg]

I'd use it.
I'd have thought that you'd only really need to steer clear of compost which had grown tomatoes and aubergines in previously.

Hello Nicos,

I've just chanced across this thread, and I see that you've cautioned against using compost for potatoes in which tomatoes and aubergines had previously been grown. Could I ask why this is, please? I'm a novice gardener, and am intrigued by this advice...

[Mr Bones]

Same family Herbsandveg (Solanaceae) so diseases that affect that family could be transferred over.

[Herbsandveg]

Now I understand...

Same family Herbsandveg (Solanaceae) so diseases that affect that family could be transferred over.

Thank you for the explanation, Mr Bones. I think I get it now..?

[Two_Sheds]

you've cautioned against using compost for potatoes in which tomatoes...had previously been grown. .

Potatoes and tomatoes both suffer from blight, and can be passed from one to the other.

However, blight spores ONLY survive on living plant tissue, eg. old tubers left in the ground, or scraps chucked in the compost heap.

I reuse old compost with no problems (the spores don't survive in compost, only on living plant tissue).