When can I lift my Swift potatoes

[Bubbles26]

Hey, We planted Swift spuds on 14th March, and so far the plants are doing well, but my question is how big do the plants need to be before I can lift them.

Or can I lift some whenever I want some new potatoes and leave the rest in to get a little bigger?

I'm desperate to know what they look like under there lol :)

[Bubbles26]

[Steve.]

Swift are an eight week crop so you could start to lift them now if you wanted, I grew these last year and did the same thing.

http://steverandles.co.uk/alottment/?p=362

Steve...:)

[Flighty]

Have a firkle, or furtle, if you prefer.  That is have a feel in the ground around one plant to see what you find. 
Dig them up to use as you go, and leave the others to get bigger.

[Squashman]

I set my swift on 15th March, although a little bit on the small side I am eating them now, just cannot wait any longer.