Digging up potatoes

Today I planned to have sausage and mash but, the kicker is, I was planning on making the mash with potatoes from the garden.

So, full of hope, I headed down to the bottom of the garden with my spade and my basket and looked at the main bed potatoes. Part of the thought here is that I know that the wet weather is causing tatties to rot in the ground around here, so I want to avoid that.

The main bed is looking a bit battered, what with the weather and what looks like quite an attack from slugs or snails or caterpillars. This highlights how little I've been checking on these plants recently

So I dug in, and what a disappointing experience it was!

I dug up two plants and all of them seemed to be very limited in their growth under the surface.

I have quite a lot of other plants in the bed, and I did select the smallest and weakest looking of the plants, but that above really is pathetic!

THIS is the one potato that I managed to extract from my brief dig.

That is about 10mm across!

So anyway, I'm not sure how you're supposed to dig these plants up as, digging the spade in made me worried about cutting through any potatoes (though with the size of them that would definitely involve more luck than judgement!) so I went to digging with my hands.

I partially uncovered some other plants just to check, and found some very small nodules like this so recovered them and left them alone.

I also found a white grub about 10mm long which I didn't get a photo of but squashed and threw out the garden, below the surface. Any ideas?

I hope the rest of my garden provides a better harvest than this!