[heygrow]

I planted 4 rows of potatoes. One row is Swift early, next row Int Kidney seconds and the following two rows main crop King Edwards. The first and seconds were planted in mid March and the Swift caught a bit of frost and so were set back a bit and are growing sloooowly, way behind the IK seconds, which seem not to have suffered any frost damage.
But here is the strange thing, the KE main crop were planted in early April and have romped away and are first to starting to develop flowers. What is going on here? I thought the main crop had to stay in for a good few months yet. What do I do when they finish flowering (looking to be around end of June)? Surely they cannot be ready to pull up then??

[mumofstig]

Leave main crop in the ground until you want to dig them up, the biggest crop will come from leaving the foliage to die back to the ground.

[heygrow]

Thanks for the advice MoS. I've not grown main crop before, just earlies.

[Salmo]

A lot of early varieties have small tops, Swift may be one of these. They bulk up at about 70 days so should be forming tubers soon. Some varieties do not flower. They form tiny flower buds which never develop.

[ARPoet]

Best thing about ealies is having a good furtle to see if you can feel any big enough for the pot.

[Hampshire Hog]

As Mum says they will bulk up. One point though have a furtle for slug damage as you may have a trade off between crop size and damage. 😱😱😱

Cheers HH

[heygrow]

I also grew some Swift and IK in bags under cover down the side of our house and these were planted beginning of March (or maybe mid Feb). Already had one lot of the swift out and they were a decent crop and size. I guess they grew more vigorously due to being sheltered and richer compost. They foliage on these grew as I would have expected the ones on the plot to.

[heygrow]

Now I know what the problem is with the swift first earlies. Lifted a couple of plants that looked distressed to find every potato full of small worms!  I'm thinking wireworm, but not sure. The worms are extreemly small, about the diameter of a needle and half inch long at most. White in colour with tenticles on their heads. I should have taken a picture. Of 15 plants all but one has been affected.

This is a new plot I took on this year, but it had been cultivated by previous holder, so was not a newly dug out grassland. The second earliers in the row next to these all look really healthy, so I plan to leave most of the swift in place to be sacrificial to save the rest of my crop.

Any thoughts and advice about this woul be appreciated. Too late for the Swift, but I woul like to prevent damage to the IK and King Edwards planted along side and also avoid the problem next year.

[heygrow]

Update! After searching the internet I'm sure that it is millipedes I have. Fit the description exactly. Definitely not wireworm.
I must have about a million millipedes in my patch to cause thus much damage!

Never heard of this problem before, so still need advice on preventing further damage to other crops. I had planned on planting leeks in here after lifting the spuds, but not sue if the millipedes will attack them. How do I get rid of them?

[JayG]

Not exactly as per your description, but the only millipede I've ever found coiled up inside holes in spuds is the spotted snake millipede.

The RHS claims they rarely damage healthy tubers but often take advantage of holes previously made by underground slugs (usually the tiny keel slugs.)
(Try gurgling images of them - the picture on the RHS page makes them appear darker and bigger than they actually are.)

It could be either that Swift are particularly vulnerable to slug damage, or the patch of soil they are being grown in is more slug-friendly (wetter?) than where the others are growing.

[heygrow]

Thanks JayG.
I don't think slugs as the damage as lots of small holes with these millipede type things in them. Holes are too small to be slugs I think. Also the potatoes are infested with them, it is not just the odd few that have taken advantage.
I'll try and get a photo. Other info on the web suggest millipedes can cause the damage to certain root veg.

[heygrow]

Well JayG you were right. I was wrong! I found the slugs in the holes and saw a large millipede scurrying off when I dug one plant up.
Slugs are the cause of the damage and the millipedes took advantage and I think laid their eggs in the holes, which must account for the large number of tiny young millipedes everywhere. So another lesson learnt!
Never had so many pest problems growing in my garden, but the allotment seems to suffer quite a lot.