[arh]

Last year my potatoes in bags had a lot of foliage, I mean the foliage was, (if upright) up to or in excess of 1m in height the mix was 30% manure,30% soil and 30% mp compost and no additional fertilizer/feed. I am beginning to think that it was the "over-abundance" of manure that produced the excess foliage.
1 - Does any one agree?
2 - What would be your preferred mix?
I'm thinking of 50/50 soil and mp compost with some sort of fertilizer, (blood,fish and bone or 7/7/7) and feeding with Tomato Feed later when they flower.
It's the quantity that i'm not sure about, either b/f/b etc. or Tomato Feed, as I have always just manured and dug.
All replies welcome, thank you.

[JayG]

Have to ask how good or bad the actual crop was, and also mention that some varieties naturally produce stronger foliage than others.

The mixture you used doesn't sound particularly high in nitrogen...

[arh]

Thank you for the reply JayG. Well, I thought that the "crop" was pretty good, though, being the first year, I don't have a "yardstick" to measure against. I had approx 20/25 kilos from 10 bags, all with 2 Desiree seed potatoes each, I say approx, because I didn't weigh them, just filled a 25k potato sack. That was with the "decent" sized ones, all the smaller ones went in another bag/fridge to be eaten whole, skins and all, and very nice they were.

[JayG]

So, about 1 kilo per plant, which is possibly at the lower end of expectations, but not bad at all.

Potatoes are quite hungry plants, so personally I would not try to reduce the amount of nutrition in your mixture.

How large were the harvested potatoes? Desiree are relatively early to mature and can get considerably bigger if left for longer. With so much foliage is it possible that the bags dried out a little between waterings, which would of course affect the yield?

[jaydig]

Last year I had a couple of potato plants develop from what must have been potato peel in the bottom of the "Dalek" compost bins that they were growing alongside.  The foliage was like a forest, and cascaded over the adjoining wall and along the ground.  The resulting crop was huge.  I didn't weigh it but it filled two large washing up bowls to overflowing from these two plants, and the potatoes were enormous.  As well as kitchen peel and garden waste I also put all of the chicken poo from my four girls, and I would imagine it was this that created such huge plants.

[arh]

Hi JayG, without doubt, (imo), the bags dried out, the problem was,
a - there was so much foliage that I coudn't find the bag to pour the water in.
b- the bags were touching one another at the start, this compounded the foliage problem,
c- there were 3 rows of parsnips next to the bags one side and 3 (small) gooseberry bushes the other side, so I couldn't get close to the bags anyway.
d - I didn't have enough water.
This year I am increasing and moving the bags to another 1/3rd of the plot, (rotation reasons), spreading them out to ensure that I can get alongside each bag, but, and this is why I posed the question, the potato plants that I remember from my youth didn't have so much foliage, and I wondered if it was the manures fault. Remembering that all my gardening experience, (which isn't much), was learnt alongside my grandparents who raised me in the country, and who only ever used manure, (cow, pig, chicken and horse, as we had all of the above), on the vegetables, (which,what where and when I do not know, as I was too young, and too stupid, to ask),  .
Without a "fairly" definitive reason, I am likely to do exactly what I did last year, regarding the composition of the bags, if only as a part of the learning curve, but if some-one who "specializes" in potatoes were to say, "don't over-manure them" for various reasons, then I would take note.
thank you for the replies.

[arh]

ps. add "human" to the list of manures, as we didn't have a flushing toilet until I was 17 years old, (I saw my first 'water toilet" at school. , and was told to "use it" before I came home)

[arh]

Thinking of what you have said and described, JayG, I'm beginning to think on the lines of doing what I did last year, with the addition of more water, (I am charting the water usage, so I know, in the summer, how much I can use), and some possible extra feeding with Tomato Feed after flowering time.

[JayG]

Whilst trying to maintain access for watering, in your situation I'd line the bags up in rows at least 2 deep to reduce the amount of evaporation due to warming from the sun (especially if the bags are black.)

Won't make that much difference, but every little helps if water is in short supply...

[arh]

That's a very good idea JayG, It'll save a bit of space and won't be any harder to get at. Thank you very much.