Fred wrote:

I posted some first early potatoes (red duke of York) in March but
there's no sign of any growth yet. Is this normal or has something
gone horribly wrong?

No - it's just a bit colder than last year.

Shortly after I planted them, we had that weekend
of snow. Although it didn't hang around long before melting, could the
cold have damaged them?

It could have if the shoots had emerged, but safe under the soil, they
should be fine. I predict you'll see something this week if it warms up
as expected...

One row of my Pentland Javelin planted on 21st March just emerged from
under their black plastic on Saturday.

Peter