[lettice]

For the last three years I have been trialling with plots side by side for my maincrop potatoes.
One plot planting 12-15 inches apart in rows and 25-30 inch between rows I have grown the traditional method of planting potatoes in rows in a six inch deep by six inch wide trench and earthing up in ridges of about two inches about three times as shoots appear.
They crop well, that being Sarpo Mira, Desiree, Rooster and Maris Piper. One row each of 12 seed potatoes with Maris in two rows each of 12 seed potatoes.
Put plenty of homegrown nematodes down pre season and during the earth ups and get little slug damage.
See some slugs moving around the plot late night and early morning that I pick off, so they are closeby.
Each row generally gives me about 60 lbs of potatoes. But about a quarter of the crop are small, with the rest being medium to large.
The Sarpo Mira is a larger potato and are a mixture of medium to large, with about a fifth smaller ones.

In the other plot, roughly 7 foot square I  have grown maincrop in potato bags, just two seed potatoes in each bag, six bags in each row.
I get 12lbs of perfect potatoes (nil slug damage) in each bag and are all medium to large for the Maris Piper and Rooster.
The Desiree yield has been 18lb per bag.
The Sarpo Mira yield is about 23-25lb of potatoes per bag and are all very large. The bag is bulging by end of September.
Sarpo Mira foilage never seems to die down and is now still green and vigorous, but have last weekend picked them all as the colder nights are setting in.
Have not suffered any potato blight, they just naturally die, Maris Piper first, then Desiree/Rooster. Sarpo Mira as above.
Pots do keep the foliage tidier to look after and stay stronger and upright longer, which I think is what gives the crop that extra yield.

They both are grown with a mixture of late autumn and spring dug garden soil from the patch they grow on, B&Q verve, potato fertiliser and a seaweed mix form my local beach.
Over the winter veg peelings are thrown over the soil and left to rot down. In the spring dig I add about 10 spadefuls of my compost to each plot.

From now on, I am moving to a potato bag only method, the yield and size is so much better.
Bags also give your back a rest as I do find earthing up rows more awkward and harder work.
I store my potatoes in hessian bags in a small shed from August/September to late spring and early Summer.
I do also freeze a load of the potatoes as mash, roast and chips for use during those summer months when we have no maincrop.
Have not bought any shop potatoes for six years or more.
I also encouraged my dad last year to grow his maincrop in bags, he does not grow anywhere near as many as me, but he did notice a big  gain in yield and size.

Have always grown my first and second earlies in potato bags and large pots around the plot and get a 10-12lb yield from them. Always grow Charlotte, Pentland Javelin and International Kidney.
But often pick a few new ones each year.
Grew Duke of York for the first time this year and were very tasty, a 12lb yield in bags, they will be on my regular list now.
Have tried Aaron Pilot, Sharpes Express, Rocket and Kestrel over the years.
Have used these suppliers for my seed potatoes from a local garden centre for the last five years.
Taylors Sarpo Mira and International Kidney.
Albert Bartlett Rooster.
Unwins for the rest.

I did also this year plant six Charlotte seed potatoes in a two foot square raised bed, six inch deep and 10 inch deep once earthed up this year. The yield was 40lb. They were all mostly medium size, not your normal expected Charlotte salad potato size. Will do that again.

Be good to hear what other methods you all use and if anyone else now uses pots or bags for maincrop.
Would say a 30-50 litre pot would be the equivalent of using a potato bag.

[mumofstig]

Sounds good to me.

Do the bags need more watering than potatoes grown in the soil? and what size bags do you use?

[lettice]

Sounds good to me.

Do the bags need more watering than potatoes grown in the soil? and what size bags do you use?

Same watering regime.
I always water late evening every other day, or daily if its really hot, certainly did this summer.
Use the shower on the hose sprinkler for a few minutes up and down the rows of bags.
Use the 18 inch depth by 12 x 12 bags.

[mumofstig]

I always water late evening every other day, or daily if its really hot, certainly did this summer.
Use the shower on the hose sprinkler for a few minutes up and down the rows of bags

We're not allowed to use hosepipes, so maybe not for me.

[snow white]

Bagged ones need watering daily.. If you forget then the yield is small.  I found that out this year.  But I did grow some in a raised bed.  Hardly any slug damage and large potatoes.  The ones in the ground grown the traditional way (apart from charlotte which I harvested early) all had 50% slug damage.  So next year its charlottes in the ground and mains in bags or raised beds.

[lettice]

I always water late evening every other day, or daily if its really hot, certainly did this summer.
Use the shower on the hose sprinkler for a few minutes up and down the rows of bags

We're not allowed to use hosepipes, so maybe not for me.

How do you normally water potatoes then?

[mumofstig]

All watering has to be done with a watering can, in a normal year, they get enough rain so I don't often bother.

[snowdrops]

I don't water potatoes in the ground either. Some years I get lucky & others I don't 😊

[lettice]

All watering has to be done with a watering can, in a normal year, they get enough rain so I don't often bother.

I would have thought being in Kent, you would have got long dry spells like we do here.
Ok, just filled up to 7 litres in a watering can using my hose in same way and time as I would do each row.
Like I said, would normally in summer only do it every other day.
But we did have some very hot dry spells this year with no rain for weeks, so I did do daily now and again.
Not found that bags need anymore watering. You have to remember that you have dug down 6 inches and raise a ground row bed by 6 inches or so. You do not fill a bag to the brim.

[SusieB]

Can I ask how much bought compost you use per bag?  It can be expensive.

[lettice]

Can I ask how much bought compost you use per bag?  It can be expensive.

Not sure I could say per each bag, but I would use two B&Q verve 50 litre bags as I mentioned above spread over the plot just before the autumn dig. The mix that I dig as above is the potato bag soil reused each year dug into the soil they sat upon, with the additions of my 10 spadefuls of homegrown compost, veg peelings along with the potato and seaweed fertiliser.
Two bags of the B&Q verve per plot would be about £7, or has been £10 or so for 3 bags for the last few years.
It has been my compost of choice, I'm sure your favourite would do just as well.

[fatbelly]

I've used Potato bags this past few seasons and get a grand crop. They are all blemish free with no slug damage.
I use the cheapest compost I can find and supplement this with a handful of growmore in each tub.
They deffo need additional watering, even up here in Cheshire where we get lots of rain each summer the pots dry out. I just give them a watering can every time I go down. I also use the same compost for 2 seasons and rely on the growmore to give the plants what they need.

One way the above method really works is the growing of Earlies. I start them off in pots in the greenhouse in late February. The extra warmth the greenhouse gives works wonders with the growth. Then in early May i move the pots out of the GH when the weather has warmed sufficiently. This way I get earlies at least 3 weeks before they are ready in the ground because the warm start they get in the GH

[Salmo]

Sounds good to me.

Do the bags need more watering than potatoes grown in the soil? and what size bags do you use?

Same watering regime.
I always water late evening every other day, or daily if its really hot, certainly did this summer.
Use the shower on the hose sprinkler for a few minutes up and down the rows of bags.
Use the 18 inch depth by 12 x 12 bags.

Is this the method where you use bags with holes for the roots and half bury them in the ground? Perhaps you could tell us in detail what you do.

[lettice]

Is this the method where you use bags with holes for the roots and half bury them in the ground? Perhaps you could tell us in detail what you do.

Nope, bags just sit on the bare soil, all 18 inches of the bag above ground.
Just as you would use a potato bag for a first/second early crop.
Potato bags always come with a few small drainage holes, much like a pot.
Have not seen the roots escape the bags to any great extent, just seen a few through those drainage holes.

From Oct to Mar, when the bags are not filled with prepared soil, they are folded up, washed and stored in shed.
The recycled soil from the bags, homegrown compost and peelings raises the soil level that the bags sit on whilst growing over the winter. The digging mixes it all up and then each bag is filled from that rejuvenated soil lowering the plot soil level again, raked level and the filled bags placed on top of the soil.

[AussieInFrance]

Thank you for opening this topic and your overview. I've been toying with the notion of growing potatoes this next season. The information is timely.

Is there any reason recycled potting mix bags couldn't be utilised? If i punched a few holes in the bottom and enriched the contents with compost it seems a worthwhile option, doesn't it?