Potato Tyres

[jumping bean]

I have three different lots of potatoes growing in tyres as per a recomendation on this site. The first lot has started to grow, how tall does it need to be before I start adding more soil/compost? And how do i know when they are ready to dig up?

[MKG]

You have to chase the things, I've discovered. They need about four inches of top growth, and that will make them outpace your every effort to earth 'em up. Just keep piling it on until you can't do it any longer - and they'll still grow higher. Flowering is the first signal for earlies - at that point you'll have some usable potatoes, and you can furtle for them (I believe that's the technical term) below the soil, leaving the plant intact to grow more. The maximum point is when the haulm (the top growth) starts to fall down and wither a bit. Then you have maximum potato growth and you can start to really dig 'em up - although you can also simply leave them in the soil until required. Get them all out before the first severe frosts, though, otherwise they will either rot in the ground or, perversely, survive and grow again the next year - right in the middle of your cabbages. Left in the ground, they're also targets for keel slugs.

EDIT: Ahhh - tyres. OK, you won't be growing cabbages there. The rest still applies.

[Ratty]

I've got spuds in tyres for the first time this year too - last year they were in the raised bed. I'm lucky enough to live next door to a bloke who 'tinkers' with cars and clearly has a problem disposing of spare tyres - so I have an almost endless supply!

My spuds (mix of earlies & maincrop) have pushed thru the level above the first tyre so I've added another plus compost/soil. I'm hoping to get them 3 tyres high and probably 4 before they flower. Good luck with yours

Ratty