Many gardeners are finding Covid 19 is restricting their choice of seed potatoes this year. But we’ll still get a good crop when buying, and then chitting, certified seed potatoes for April planting.
Twenty five years ago,
well-known tattie guru, Alan Romans, and I organised Scotland’s first seed potato day. At this and later events run by Borders Organic Gardeners, over 100 different potato varieties were sold by the tuber.
Sadly, for the first time, there will be no Borders potato day this year or any of the other smaller events that have since grown up. So thousands of tattie growers must look elsewhere.
Garden centres and mail order suppliers offer a much more restricted choice, usually around 30 varieties. And these potatoes are sold in 1kg and 2kg bags, 10-20 tubers, not by the individual tuber as at potato days. A few companies do offer ‘collection packs’ containing, say, 3 tubers of each of 3 varieties.
It looks as if seed potato supplies are lower than usual this year, because when looking at mail order websites, I see some varieties are already sold out. So get your tatties now!
However restricted the choice becomes, leading potato expert, John Marshall, is urging gardeners to only buy certified seed potatoes.
“Don’t be tempted to use supermarket table potatoes no matter how good they look,” he says.
We were discussing the importance of buying and growing safe seed potatoes and exploring how the present certification system works.
SASA, Science and Advice for Scottish Agriculture, began the certification process in 1910 by examining varietal purity and looking for evidence of fungal wart disease. They then started checking for viruses.
In ensuring pure, healthy potatoes, SASA initially took stem cuttings and later began micro-propagation.
SASA also produces tubers from fresh seed every year and farmers then use clean soil where no potatoes have been grown for several years.
They regularly check the crop for unhealthy, possibly virus-ridden, plants and rogue out, or remove, any dubious ones. Inspections continue during storage.
As added protection, several suppliers have formed the Safe Haven Scheme, checking for other disorders such as brown and ring rot. Those in the scheme have a tractor on the plant label.
As John remarked, Covid 19 has highlighted the risk from viruses and their ability to mutate.
What an irony that the UK is torpedoing the Scottish seed potato industry by banning the export of Europe’s most rigorously controlled seed potatoes to the EU. Many importers, especially in Ireland, Germany and Switzerland are very unhappy.
After wisely buying seed potatoes earlier than usual, what then? ‘Chitting’ is widely, but by not universally recommended. The aim is to give tubers a head start, thereby ensuring an earlier crop.
Place egg boxes near a window in a cool, frost-free room and arrange seed potatoes upright with the bud or rose end at the top and the tail or stem end at the bottom. There’s a small scar at the tail where the tuber had been attached to the parent plant.
Don’t leave all the sprouts to grow on. You need to do more than rub some off before planting. Sprouts will regrow, weakening the plant and producing lots of marble-sized tubers.
Instead, before setting out the seed potatoes to chit, remove any buds growing in the centre of the rose. Use a potato peeler to dig out around 3mm of flesh at these eyes. Others will sprout on the sides.
With 1st Earlies, I leave all the other strongly-growing buds, thereby having a lot of small, but not tiny tatties. Where you want larger potatoes, as with 2nd Earlies and Maincrop, only leave the best 3 or 4 little sprouting shoots.
Plant of the week
Helleborus niger ‘HGC Joshua’ is a semi-evergreen hellebore that, in late winter, bears white, outward facing flowers on sturdy stems. These fade to a pretty light green. Happiest in semi-shade.