[xt600]

Hi all...I'm about to lift my early potatoes to free up some space on my allotment.
I'm my kitchen, I have a bag of supermarket potatoes, 'Marfona' which are 'second earlies' I believe. They are sprouting shoots and I was wondering if it was worthwhile planting these out now for a late crop?
Any advice appreciated :-)

[DD.]

They are not certified seed.

You run the risk of introducing diseases into your soil.

[xt600]

They are not certified seed.

You run the risk of introducing diseases into your soil.

Thanks, but that doesn't answer my question.
None of the potatoes I grow are 'certified seed'. I choose healthy looking potatoes at supermarket prices and thus far have had no problems with pests or disease. I have also saved myself a few quid making it far more viable to grow my own!

[Yorkie]

Then you have been very lucky not to cause yourself problems or, more importantly, problems for the rest of your allotment site.

To answer your question.  The soil will have a build up of pests and diseases which spuds are prone to.  It will be depleted of necessary nutrients as the old spuds are hungry plants.  But there may be time to get them in and get a smallish crop.

[Crazycavey]

I have finished lifting my earlies  Good crop golf ball to lemon size new pots.

However I noticed 60% of the sead potatoes were still like new or quite healthy looking and after prizing them off the plant they still havee one or two chitting points that look quite fresh.

Could I sow these again to get a crop of lates from the same seed potatoes?

[Yorkie]

The previous advice from a professional potato grower on this site was that you had to leave 60 days between harvest and re-sowing.  That's cutting it a bit fine if they are second earlies.

Also there is the risk of re-introducing any pests or diseases that might be present in small quantities at the moment but will grow further if you plant back into the same soil in the same season.  Original seed tubers are certified virus free for a good reason.

The soil will also be severely depleted of necessary nutrients so will need replenishing.

[Y.E.A.H]

To save starting another thread... Is it too late to actually plant main crop seed potatoes?!
Thanks  

[xt600]

I can understand that proper seed potatoes are certified as disease free, but surely this doesn't mean that ALL others are riddled with disease? If 'supermarket' potatoes have diseases, then surely these will be visible? I have only ever planted ones which looked 'perfect' and never had problems. I can understand why seed producers want us all to believe that only 'their' potatoes are worth planting but surely a bit of common sense can be applied here?

[mumofstig]

To save starting another thread... Is it too late to actually plant main crop seed potatoes?!
Thanks 

mmm I wonder if they'd make it before the cold weather started......20 weeks in the ground...takes you into November, so I'd think not.
You could try and hope for a mild autumn and just lift what's there if it turns cold  

[mumofstig]

I can understand that proper seed potatoes are certified as disease free, but surely this doesn't mean that ALL others are riddled with disease? If 'supermarket' potatoes have diseases, then surely these will be visible? I have only ever planted ones which looked 'perfect' and never had problems. I can understand why seed producers want us all to believe that only 'their' potatoes are worth planting but surely a bit of common sense can be applied here?

You don't have to take on board the advice offered here, but there's no need to argue with it either. If you think it's ok to plant supermarket spuds then there is nothing to stop you, we just don't advise it. Simples!

[Y.E.A.H]

mmm I wonder if they'd make it before the cold weather started......20 weeks in the ground...takes you into November, so I'd think not.
You could try and hope for a mild autumn and just lift what's there if it turns cold 

Thank mum 

[Yorkie]

I can understand that proper seed potatoes are certified as disease free, but surely this doesn't mean that ALL others are riddled with disease? If 'supermarket' potatoes have diseases, then surely these will be visible? I have only ever planted ones which looked 'perfect' and never had problems. I can understand why seed producers want us all to believe that only 'their' potatoes are worth planting but surely a bit of common sense can be applied here?

No, it does not mean that all others are riddled with disease.  However, it is not as easy as you suggest to identify rogue spuds and the potential risks are immense.

Please see these two threads:
http://chat.allotment-garden.org/index.php?topic=28856.0

and, in particular, post #10 in this thread:
http://chat.allotment-garden.org/index.php?topic=50572.msg599384#msg599384

Iain, the professional grower I referred to previously, was not able to spot disease.  I very much doubt that any amateurs will be any better at it than him.  I also doubt that most amateur growers are familiar with the full list of possible diseases, not to mention their symptoms.

[xt600]

I can understand that proper seed potatoes are certified as disease free, but surely this doesn't mean that ALL others are riddled with disease? If 'supermarket' potatoes have diseases, then surely these will be visible? I have only ever planted ones which looked 'perfect' and never had problems. I can understand why seed producers want us all to believe that only 'their' potatoes are worth planting but surely a bit of common sense can be applied here?

You don't have to take on board the advice offered here, but there's no need to argue with it either. If you think it's ok to plant supermarket spuds then there is nothing to stop you, we just don't advise it. Simples!

I'm not argueing with you, I'm simply having a debate, if that's allright with you!:-)
My parents started one of the first organic farms in Cornwall, back in 1970. We always used our own spuds for seed, year after year, and I don't remember ever having any problems. It's been many years since I've had the opportunity to grow stuff again and sites like this one are great for information and advice.  
I do however feel that when it comes to potatoes, we have to strike a balance between what the seed producers wish us to believe, and actual reality and economics! It's a bit like asking the local garage if it's a good idea to fix the brakes on the car yourself...they'll surely tell you of the death and destructon it's likely to cause, but in reality you may even do a better job than the garage would!
Anyway, after all this I'm not sure my original question has actually been answered: If I plant some Marfona in the next couple of weeks what is the likelyhood they'll produce a reasonable crop, given Cornwall's mild climate? Anyone?

[Ice]

We are not seed producers and have no vested interest in the advice we give.  We are just amateur growers with decades of experience between us which we take the time to share with others.  If you know better or doubt the advice we give that is your perogative.  I won't be fixing the brakes on my car any time soon.

[xt600]

We are not seed producers and have no vested interest in the advice we give.  We are just amateur growers with decades of experience between us which we take the time to share with others.  If you know better or doubt the advice we give that is your perogative.  I won't be fixing the brakes on my car any time soon.

Instead of lambasting me for daring to spark a debate, how about actually answering my question Mr Ice?