[AlaninCarlisle]

I suppose I shouldn't grumble as I'm still harvesting good sized celeriac. However the last couple I've pulled, when sliced, are riddled with tiny tunnels although there is no sign of whatever it was that did the tunnelling.

I thought it might have been carrot fly except that the tunnels go deep into the veg and are not concentrated around the top as in carrot fly.

Anyone any idea as to what might be causing it and therefore any action I could take to avoid a recurrence this coming season?

[Totty]

Some of mine have had some holes, and have had woodlice in em. Not sure if they made the holes though.

Totty

[JayG]

Impossible to be certain but there is a good chance that your problem was caused by carrot fly attack, because celeriac is unfortunately from the same family as parsley, carrots, celery and parsnips.

There will be no sign of the larvae now as they will have turned into flies, some of which will be overwintering in the soil. (You are "lucky" if the larvae only attack the tops of your carrots Alan - that tends to happen only with parsnips here; carrots are usually pretty comprehensively ruined from top to bottom.  )

Rotation and fine-meshed protection of the crop is the only sure way of preventing trouble with any of these crops, although you may get your own back at least partially by turning the soil over a few times in winter in the hope that frost and predators will deal with the little buzzers!

Last year I grew early carrots, comprehensively enviromeshed, on a patch I'd grown parsnips in the year before - guess what? (They should have left the soil and flown away in spring but spring was very late last year and I suspect I trapped a few of them underneath the "protective" covering....  )

[sunshineband]

If not carrot fly, then wireworms. These are easier to see and can be hand picked during cultivation.

[Agatha]

At least it's only small holes - half mine have been hollowed out by mice - they went in just below ground level, so the celeriac looked perfect until the leaves collapsed!

[AlaninCarlisle]

At least it's only small holes - half mine have been hollowed out by mice - they went in just below ground level, so the celeriac looked perfect until the leaves collapsed!

Oh, I've had that too, also with my beetroot.

[RJR_38]

Slugs had fun with mine, filling them with tunnels :(not sure I can be bothered to grow it this year - a lot of effort for not much return 

[Jackypam]

My swedes were completely hollow and I have no idea what did it.  Do you think it might be mice then?

[Agatha]

Might be - if you look closely, you can probably see the teeth marks if it is mice or voles.

[Jackypam]

Yep, mice!  And to think I rescued the nest in my compost heap last spring ...