when to start 1st earlies

I've re-planted haulms on my allotment. I usually do this when I start (impatiently) carefully lifting 1st earlies for a few 'new spuds'. If I find that there are still a lot of small tubers starting, I replant carefully and water in. Treat them like a newly planted pot plant remembering to water when they need it, and you should be rewarded with a decent crop of potatoes later on.

We grew some Lady Christle (3 per big pot), in the greenhouse last year, and they cropped earlier as everyone said here!

But we also replanted the halms, and got the same amount again a couple of months later, when they were outside!

One of my veg suppliers at work (garden centre) does potates ready growing in a largish pot.  I know, I know, but people ask for them, so you have to stock nonsense like this 

The label said replant into soil or a bigger pot for more crop, but the driver told me the nursery guys had tried them and knocked them out of the pot, picked the spuds carefully, then replanted in a slightly bigger pot with some fresh compost.  Kept fed and watered, they had had several crops from each plant.

We were amazed to hear it, but we did do much the same on a display pot we planted up and it does work.  Bit of a faff, but if you have limited space and either a cold greenhouse or a polytunnel, its worth a go 

Now - in pots in a frost free greenhouse.
Early March - under plastic cloches or in a cold greehouse.
End of March / early April - normal outside planting.
March sowing's can still get checked by frost. Keep an eye on the weather and cover the tops with fleece if there is a risk of frost.