I would imagine that you are a little late to buy some seed potatoes. You could look out for some of last year's old potatoes that are beginning to sprout. They will take quite a long time to produce a crop if they are main crop potatoes though. My best guess would be to look out for some of last year's old salad potatoes, something like Charlotte which won't take too long to give you a viable crop. I would go for some early varieties next year and they will need a shorter growing season and will best suited for growing in bags.

Go get some seed potatoes from the garden center and 3 bags of compost. 1 for each grow bag. Now your are ready start growing. What kind of potatoes? Whatever looks good. It's that simple. 3 bags, you can pick 3 kinds of potatoes. Some big favorites around here are Yukon Golds, Red potatoes, Russet, Idaho. Not sure if these are available in the UK but I heard good things about King Edwards - they are a lot like Russets. They are all delicious so you win regardless.

If the seed potato has many 'eyes,' slice in half and let the slices sit out on the counter for couple days to calous over. Make sure each slice has a couple 'eyes.' Each slice can be a separate plant.

Fill each grow bag with ONLY 10 inches of compost and roll down the bag to the soil level forming a collar around the bag at soil level. Plant 2 or 3 seed potatoes in each grow bag and water. Not more or you'll only get teeny tiny potatoes. You want nice big baseball size potatoes. Place in a sunny location and keep soil evenly moist at all times. Don't ever let the bags dry out.

In about 10 days, you'll notice sprouts shooting up. When the sprouts reach about 5 inches or so, add more of the compost up to the top set of leaves and roll the 'collar' up to soil level. Keep adding more and more compost as the sprouts grow until the entire bag is full of compost. Keep it watered at all times. Potatoes are very thirsty. You have to 'mother' them.

When you see little flowers blooming, the potatoes are almost ready. When the leaves turn yellow and fall, your potatoes are ready to harvest. You can just cut the bags open to get your potatoes. Here is an interesting and fun video to show you how.

https://www.youtube.com/watch?v=PL_gMmK3UtU

Bathgate in the UK seed potatoes will all have been sold, they go on sale in February. Aztec already has the bags t grow them in...

Aztec, not all potatoes flower so don't think that is a hard and fast rule.

I just checked and you can get seed potatoes now in the UK from Suttons. They still have several varieties available you can order online. Don't worry too much about variety. They are all delicious. Here is the link and I'm writing this from New York. Your Potato plants will let you know when the potatoes are ready to harvest - when the leaves go yellow and fall.

http://www.suttons.co.uk/Gardening/Gift+Ideas/Christmas+Gifts/All+Christmas+Gifts/Seed+Potatoes+-+Anya+1kg_234277.htm

Bathgate did you notice that the dispatch date is December 2017? They aren't actually available right now but you can pre-order them...

They were ready to accept my order. You may check a few other outlets as well. I can't believe they aren't available anywhere.

Yes they will accept your order but the dispatch date isn't until December; I too could have ordered for delivery then. Given that seed potato are, usually, planted in the UK not later than early April it is hardly surprising they aren't available the sprints on them would be a good foot in length!

MG, I'm glad you have given the obvious answer. I think Bathgate is confusing with the fact that some suppliers sell small packs of tubers which can, it would seem be planted sometime in early September for Christmas. I would imagine that if they are grown this late in the season then if the frosts don't get them (especially up North) then the blight will.

Thanks Jimmy... yup frost or blight, one or the other will get them. Personally I wouldn't try to start growing potatoes at this time of the year - grown something which will crop and then buy seed potatoes next January time allow them to produce sprouts and away you go...

...and I can drive down the street now and purchase a pack of seed potatoes in about 30 minutes. They are as common as grass right now. We have Early Season (ready to harvest in 65 days), mid-season (harvest in 80 days) & late-season varieties (harvest after 90 days). Everybody and their cousins are growing them and they sure can do and yes they can and do and you can too. Gardening in the UK - an enigma!

Growing most vegetable crops is dictated by the light. You sow them in early spring to grow as the days lengthen, then harvest them in autumn. Of course there are crops that grow over winer but, in general sow in spring and harvest in summer/autumn is the rule of thumb.

Bathgate gardens in Long Island, which has later spring planting dates than the UK. Here in the southern Arizona desert, the potato farmers buy seed potatoes by the the ton in October, for harvest in February or March. It's hard for home gardeners to find seed potatoes in small lots in October, though--the bulb and seed brokers see "Zone 9", and they immediately think that we have an early spring planting date, like Tacoma, Washington! No point in planting in spring, here, since the summer heat kills the plants before tubers form. Every climate has its own planting dates.

Aztec,you will have stay with the typical dates for your location. Thanks everybody for clarification.

And, Tugb. I was only talking about growing in the UK - would not presume to make a judgement on what can grow when anywhere else on the planet :)

Sorry, MG, I wasn't directing the comment to you--I know that you know better! :) I was hoping to make the point for other members, especially the new members.
For some veggies, day length is critical to the planting date, for others, temperature rules, for most, it's a varying combination of the two. After almost 50 years of gardening, I am still sorting them out. Gardening literature isn't much help, either, unless it is written by an expert with experience in your climate. I once read a book which supposedly set out everything there was to know about the cabbage relatives (cole crops). Outside of a fascinating chapter on the origin of various cole crops, the book was mostly about how to grow cabbage in the UK. The info on cauliflower and broccoli, which was what I really wanted to know, then, boiled down to, "I really don't know much, because we don't grow much of that here."

Here, the weather is very cool for this time of year, unlike previous years. It's great for growing cabbage, potatoes & beets; not so great for tomatoes which came to a stop. I would be hard pressed to give a specific date. Yet sometimes my tomatoes will keep producing well into October and those are always the best tasting ones.

No worries Tugb. Bathgate, after temperatures in the low 20˚C here at the end of May the last two days have seen nothing but torrential rain and a rapid drop in temperature - isn't going to help any of the plants grow...