I usually plant first/second earlies 15cm deep then immediately earth up another 15cm and leave them to it. I don’t seem to suffer with green potatoes near the surface. This year, I am short of soil in that raised bed as it needed topping up, but couldn't get my usual delivery. Instead I have used half-rotted homemade compost that has donkey manure mixed in it for both a general mulch and the earthing up part. I am hoping that, by the time the shoots start developing the DM will have lost it’s potency and won’t burn the young plants 🤞
Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
I do grow potatoes commercially on a small scale myself and a larger scale at work. the only reason we earth up earlies is to suppress weeds, when using a tractor to hill this is the easiest way it does not increase the yield of early potatoes although it will delay the harvest slightly. Potatoes are like tomatoes, they come in both determinate and indeterminate types, most first earlies are determinate, so no matter how much stem you bury you will not get a single extra potato. Late types may be indeterminate and with them burying more stem will increase the yield if you have a long enough season. (think those you-tubes of potato towers)
What I meant by pushing up is that all the tubers set in the ground then as they swell up the bottom ones push the top ones up out of the ground, obviously the larger the potato the more of an issue this becomes!
I do grow potatoes commercially on a small scale myself and a larger scale at work. the only reason we earth up earlies is to suppress weeds, when using a tractor to hill this is the easiest way it does not increase the yield of early potatoes although it will delay the harvest slightly. Potatoes are like tomatoes, they come in both determinate and indeterminate types, most first earlies are determinate, so no matter how much stem you bury you will not get a single extra potato. Late types may be indeterminate and with them burying more stem will increase the yield if you have a long enough season. (think those you-tubes of potato towers)
What I meant by pushing up is that all the tubers set in the ground then as they swell up the bottom ones push the top ones up out of the ground, obviously the larger the potato the more of an issue this becomes!
Skandi that’s a great explanation and very helpful.
The farmers' potato planting machinery has 'mould boards' behind it which forms the ridges seen in the potato fields. I certainly don't know any farmers who do any earthing up after that. They grow their potato rows pretty close together and there wouldn't be any spare soil after the initial ridge is formed.
Earthing up potatoes in the garden/allotment also helps prevent the foliage getting nipped by a late frost of course ... most large potato farmers will use a biodegradable fleece-type fabric to prevent frost damage nowadays if there's a late frost forecast when the foliage is through the ridge.
@Robmarston I usually stop earthing up potatoes when there's no free soil between the rows and I'm sure the frosts are over.
Other veg that spring to mind that are/can be earthed up are
celery (although nowadays there are self-blanching varieties, the old fashioned Fenland-grown properly blanched white stemmed celery is far superior in quality to the green self blanched varieties)
and
leeks ... earthing up increases the length of lovely white blanched leek which is the most desirable part for cooking.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
That’s interesting about the indeterminate and determinate varieties @Skandi. Not actually correct, but to me, Charlotte is ‘first early’ and Pink Fir Apple are ‘second early’ simply because they crop much earlier here. This year, I couldn’t get these, my usual varieties, so am trying new ones, like Dolwen de Bretagne, so no idea how they will fare!
Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
I’ve only grown potatoes once before. I had a load of fresh turves that I didn’t wait to rot down but piled into a new raised bed. I planted the potatoes deep in that. I got a good crop (I guess?) but didn’t get any frosts and didn’t earth up. As it was my first time I was happy to just suck it and see. One thing I did notice was how wonderful the soil was after. All the grass and roots had gone and left a lovely bed of soil. Is this normal?
I’ve never earthed up leeks, but did what Monty suggested and put them into wide holes @Dovefromabove. I was reasonably happy with them, but they could definitely benefited from more white. Think I’ll earth them up this year!
"... If you want to increase the blanched length of the leek, gently earth up around them but avoid soil getting between the leaves. A collar made from a toilet roll or kitchen roll inner cut lengthways or a piece of newspaper can be fitted around them and held in place with a piece of string or a rubber band before earthing up ...." https://www.allotment-garden.org/vegetable/leeks-growing/
I've always made a tube of folded newspaper tied around with string. Toilet roll inners weren't fat enough for the leeks I hoped to grow, back in the day when I grew them
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
I do earth up around sweetcorn stems, as the roots tend to peek out of the ground and it helps to stabilise them. Also cucumbers and courgettes get planted on a little mound with a moat around them for watering which helps to keep the leaves off the ground and prevent root rot. I don’t earth up leeks, just make deep holes and pop the little plants in so they are mostly buried apart from a bit of top growth, water them in but don’t firm the soil, the leeks grow to fill the space on their own. I think its the depth of the planting hole that is important, Rob, rather than the width, but the latter is still about three times the width of the young plants as well. I had never thought of earthing them up as well, but sounds logical @Dovefromabove to get even more white.
Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
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Earthing up potatoes in the garden/allotment also helps prevent the foliage getting nipped by a late frost of course ... most large potato farmers will use a biodegradable fleece-type fabric to prevent frost damage nowadays if there's a late frost forecast when the foliage is through the ridge.
@Robmarston I usually stop earthing up potatoes when there's no free soil between the rows and I'm sure the frosts are over.
Other veg that spring to mind that are/can be earthed up are
celery (although nowadays there are self-blanching varieties, the old fashioned Fenland-grown properly blanched white stemmed celery is far superior in quality to the green self blanched varieties)
and
leeks ... earthing up increases the length of lovely white blanched leek which is the most desirable part for cooking.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
"... If you want to increase the blanched length of the leek, gently earth up around them but avoid soil getting between the leaves. A collar made from a toilet roll or kitchen roll inner cut lengthways or a piece of newspaper can be fitted around them and held in place with a piece of string or a rubber band before earthing up ...." https://www.allotment-garden.org/vegetable/leeks-growing/
I've always made a tube of folded newspaper tied around with string. Toilet roll inners weren't fat enough for the leeks I hoped to grow, back in the day when I grew them
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
I admit I am lazy and dont earth up as no one has really convinced me I need to.
I am not a big spud fan so I am satisfied with what I get......each to our own.