Potato grow bags, can I plant earlier?

[ioan]

I'm growing mine in 30l pots, which seem to take a little less compost when full than a full potato bag, so I would think 35l is comparable to a potato bag. 2 or 3 to a pot - I have stuffed 4 in in the past, but I don't think you get any more potatoes by cramming more in. I put mine near the bottom of the bags/pots, on about 2-3 inches of compost. The potatoes will only form above the seed potato so don't plant them too near the surface. Once the shoots reach the surface you need to put more compost in until the pots are nearly full to encourage more potatoes to form. Wait until they are showing greenery before watering.

Hi pen
lot's of excellent advice in this thread.
However this is the one I have been most impressed with, cos I didn't know the new spuds grew over the top
of the seed potato.
Now I know a little more of the natural inclination of the spud itself, I can get on with it.
Kind regards
ioan

[Lamboluke]

So do you cover all of the greenery or leave some for the plants to take in sunlight?

[Bohobumble]

That's what I am doing (8 x Swift from £land, 6 x Aaron Pilot that chitted sooner than planned).

I have them in pots/compost bags in my ordinarily unheated greenhouse, I am keeping the compost just moist but not wet. I am being a little more brutal with mine, they have two choices if it's frosty (grow or don't). If it's forecasted to be very cold then I take the edge off with an open flame overnight but I am not wrapping them up in owt.

Another plotholder showed me his spuds grown in a similar fashion last year in April. I am copying him!

This is in addition to the earlies/maincrop spuds I have chitting away merrily for planting direct in soil later on so if the worst happens, ah well!

[Penellype]

I cover the greenery, but others don't. Actually what I tend to do nowadays because its easier, is fill the bags nearly to the top when I plant them. I don't think it really makes much difference eitehr way though.

[Potstubsdustbins]

If a frost is forecast cover the haulm to protect it if not leave some greenery above ground to help growth, after all that's why its there.

[Kristen]

Hi
I have containers for my spuds in the greenhouse, size I would say 35ltr .
at the moment they are half full of damp compost and I want to put my spuds in now.
how many spuds per pot do you recommend, and how deep do I plant them.
also should I wait for growth before giving them good soaking.

Generally about 10L of compost per seed potato. I have tried 4 seed potatoes in the bags sold for growing Potatoes (which are about 30L) and I think 3 worked as well, although I see advice on some seed potato selling websites (could there be a link? asks Cynical Me!) showing 6 seed potatoes, 3 planted lower, 3 higher.

Plant them with about 4" of compost under them, and 4" over them, then as they grow up add more compost (either cover them, or try to put it around the stems leaving some leaf showing, not sure either way makes any difference) until the container is full.

Water them in at the start, or use compost that is already damp (if you squeeze a handful tightly in your fist no water should come out, but it should be damp enough that it nearly does, if that makes sense?!)

Then don't water again until the shoots are above the compost.

[Jonnyt]

T&M I think trialed earthing up or just putting the compost in to the top. Apparently it made no difference so it's just as easy to plant on 2 to 6 inch of Compost (different sites have different opinions) and just fill the Container up

[Lamboluke]

T&M I think trialed earthing up or just putting the compost in to the top. Apparently it made no difference so it's just as easy to plant on 2 to 6 inch of Compost (different sites have different opinions) and just fill the Container up

Given those results, do we know at what stage the potatoes actually form? I'm guessing once the foliage is at the top and light is hitting it to assist the growth of potatoes lower down as otherwise we would be able to grow potatoes in the dark with no light requiremen.

[Penellype]

The potatoes form on the stems growing upwards from the seed potato, sometimes on side branches from those stems. They usually start to swell around the time the flower buds form, so by then the plant will have plenty of foliage. The foliage is certainly essential for formation of potatoes of any sensible size.

[ioan]

Hi
when I put my semi chitted spuds in first, I watered each one about half a cup off luke warm water,
because I didn't want to do a full on water this early.
Anyway after taking your advice I removed them to place them further down the tub, now bearing in mind they had
only been in a couple of days and barely covered, I was surprised to find them hydrated really tight in thier skin,
noticeably darker in colour, fresh progress on the chits, and tiny root sprouts.
just thought I would share this with you.
kind regards
ioan

[Kristen]

T&M I think trialed earthing up or just putting the compost in to the top. Apparently it made no difference so it's just as easy to plant on 2 to 6 inch of Compost (different sites have different opinions) and just fill the Container up

Farmers using machinery to plant out seed tubers make earthed up ridges as the tubers are planted and, AFAIK, "that's it" for the duration of the crop, so not essential to earth-up-as-they-grow.

For me, for outdoor spuds, I use earthing up as a means of getting the foliage underground when a late frost is forecast, after that threat has passed (or the plants are too big!) I give them their "final" earthing up to keep the light off any developing spuds, and to have the maximum length of shoots under ground for the plant to form potatoes from.

But it seems to me that earlies don't make much in the way of spuds "up" the stems, whereas mains do a better job. In my Bags (of earlies) I get very few spuds near the surface. I have contemplated planting more tubers, some deep some shallow, to make better use of the depth of compost ... but I wonder if, other than that, Earlies need anything like that depth (and therefore "cost") of compost in containers?