Sarpo Mira behaving badly

[Daveswife]

Having had great results from Sarpo Mira in previous years, growing the tubers in tubs and without a hint of blight, I bought new seed potatoes this year and they are planted in a series of tubs. One batch came from Wilko, one online along with all the seeds we ordered this year, and at the garden centre I could not resist also buying International Kidney since these are recommended by a friend. Also, later still, bought Sarpo Axona on-line.

The first batch of Sarpo Mira ex Wilko were planted in their tubs but unfortunately I did not note in the gardening diary when they were planted, but I guess April. Later I planted the International Kidney and the next batch of Sarpo Mira and later still I planted the Sarpo Axona. With the exception of the Wilko seed potatoes the others are all looking good.

All batches/varieties are planted in the same mix of garden soil, spent potting compost and compost from our own bins, plus a few chicken manure pellets for good measure. All buckets have received the same attention, regularly watered, earthed up with a similar mix.

However after an enthusiastic start the Wilko Sarpo Mira now look pathetic, they have stopped growing, and there are brown blotches on the leaves. It is not blight but more like some sort of deficiency so I have watered with Miracle Gro in the hope of a miracle. No such luck!

I turned out the first bin and yes there were potatoes in there but tiny ones. Also turned out a bucket of International Kidney which were planted around a month later and there were so many potatoes in there that the bucket was distorted. The remaining buckets of Sarpo Mira and Sarpo Axona were planted later and have healthy tops but it is too soon to investigate the contents.

HELP - does anyone have an ideas what has gone wrong?

I am tempted to empty out all the pathetic ex-Wilko Sarpo Mira, destroy the tops and just make the best of what few potatoes there are. And lean the lesson and not buy from Wilko - it's not as if they were cheap!

[realfood]

They probably have not had enough time to grow. Mira and Axona are late maincrops, and I sometimes do not lift them till October as they continue growing.

[Monika]

Angie, we have grown Sarpo Mira since they were first available and we have never had such a bad crop as this year. Ours are grown in open beds , not raised beds, and our plants lingered without attaining the full foliage. So we dug up two plants recently and found the crop very small, much smaller than they should be at this time of the year. In our case, I blame the very dry weather we had in May, June and July.

All our potatoes (Kestrel, Rocket, Cara and Safari as well as Sarpo Mira) have not cropped at all well this year.

[Colin Miles]

I had a conversation a couple of years ago with Alan Romans and he commented that there is a crucial stage when the plant decides how many potatoes it is going to grow. If it is too dry then you won't get many - I got barely half a dozen from each Charlotte that year whereas this year some plants had as many as 18 or 20.

We have been lucky here in that the dry period probably didn't affect the Charlotte but the Desiree and Bonnie were affected. Not many potatoes from either variety - some of Bonnie only 3 or 4 though quite large.

I also grow potatoes in pots and again watering them is absolutely crucial. Pots can dry out very quickly and potatoes are very thirsty plants.

[Monika]

Colin, those comments are very interesting. It supports our yields this year in that the potatoes planted in large pots at home and watered assiduously, cropped very well whereas those on the allotment which is some distance away and watering them is impractical, given the terrain and our age, let us down so badly this year.
At one point, the soil was bone dry even at a fair depth.

[PLUMPUDDING]

I agree that watering at a certain time in their development affects the crop, but it is rather difficult to decide when that is. My Charlotte also had an excellent crop, but a few other varieties were very poor producing few or much smaller than normal potatoes. They were all in the same area of the garden and a mixture of earlies mid and late but some earlies were good and others not likewise with the mid and lates, so impossible to work out the individual needs for each variety, so I think there may be other things apart from just watering to take into account.