Potato Growing Masterclass: My Tips for a Bigger, Better Harvest

Everyone loves potatoes and anyone can grow them, so today we're doing a deep dive into  the wonderful world of the humble spud! We'll explore what to grow,  how to get the biggest, best and most blemish-free harvest  - and if you haven't got much room, well we've got you covered too, because  we will be planting up a few of these. And growing potato starts,  would you believe it, right now!

I have been so looking forward  to sharing this video. Why? Because potatoes are hands down the  most versatile vegetable of all.

Let's start with a look at what you can grow, and I've got three different  types here to illustrate my point. For the gardener's purposes  potatoes are classified by how long they take to go from planting to harvest. First early potatoes, or early season  spuds are quickest off the block, taking as little as 10 weeks.

Now these guys tend to have thinner skins,  which means there's no need to peel them, and you'll find lots of salad  potatoes in this category. And we will be planting some of these in a minute. Then you've got your midseason,  or second early potatoes, which take 12 to 14 weeks  from planting to harvest.

They're ready from around midsummer onwards. And then finally, our late season, or maincrops. They take a bit longer.

They're ready from late  summer onwards and they need a bit more space, but the payoff is generally much bigger tubers that store for months and months  on end in favorable conditions. With literally hundreds of varieties  to try in each of these categories, my advice is to kick back with a nice cuppa  and study the variety descriptions with care. Now perhaps you want a fluffy, floury  potato that's great for baking and mashing.

Or maybe a firm and waxy potato that holds  well when boiled and is perfect for salads. Or perhaps an all-purpose potato  - perfect if you don't have the space but want to grow lots of  different types and want it all. I also like to keep an eye out for  varieties promising good resistance to disease and pests such as slugs and nematodes.

Again, the advice is to study  the variety description with a discerning eye and make sure  you're getting what you need. Me? This year I'm opting for a  blight-resistant variety called 'Sarpo Mira', as well as some early season  - first early - potatoes to plant now.

You've probably heard that you need to sprout or  chit your potatoes, but is it really necessary? Well, it isn't really necessary,  but earlier on in the season it can buy you a really valuable head start  when temperatures are still quite cold. By sprouting your seed potatoes like  this you'll maybe be one to two weeks ahead of unsprouted potatoes,  and earlier on in the season, when soil temperatures are still quite  cool, that can make all the difference.

Chitting is really very simple: you just want  to lay your seed potatoes out so that the end with the most eyes - that's these kind of  little dimple bits here - faces upwards, because that's where the little  sprouts will emerge from. There's usually a very obvious, kind of upper side to the potato and a lower side,  so just lay them out like that. Now with larger potatoes you  can actually cut them in half, so long as each half has at least two or  three dimples, or little eyes to them.

Chit your potatoes somewhere that  is bright and cool but frost-free. I just leave mine out in the greenhouse here  and bring them inside if a frost threatens. You could just leave yours on a cool, sunny windowsill inside - that's absolutely  fine - but just don't keep them in the dark because what you will get then is long,  soft and spindly shoots prone to snapping.

What we want are short and stubby ones  like this. That's the golden standard. The more sprouts you have on your seed potato, the more potatoes you might get  but the smaller they will be.

So if you want fewer but larger  potatoes you have two options. You can either cut out some of the eyes at this  stage - carefully not to cut yourself, like that. So that can't now sprout and you're leaving fewer.

Or if they have sprouted, just kind of rub off one  of the sprouts like that to leave just one or two. Now I don't mind lots of smaller potatoes,  so I'm going to leave mine just as they are. Just chit your potatoes the moment you get hold of them and keep them like this  until you are ready to plant.

Did you know that potatoes are  either determinate or indeterminate, just like tomatoes to which  they are closely related? I didn't until recently, but knowing what type you have can greatly influence  how you decide to grow them. But what does all that mean I hear you ask?

Well, determinate potatoes tend to  produce their tubers more in one layer. Now because of this they'll benefit  from a mulch to shade the soil, so that any tubers that poke through  are nicely shaded and won't turn green. Indeterminate potatoes on the other hand produce  their tubers in multiple layers, more vertically.

That means you get many more tubers, but to  create more space for those tubers to swell you'll need to draw up the soil around  the stems to create more room for them. Once you've got your head around all of this  it's an absolute revelation, let me tell you! Now here's a list of some common varieties.

And  there are lots of lists and tables out there, so do just search for your variety to see  whether it is indeterminate or determinate, and choose your growing method accordingly. And more on all of this as  we go through the video. The most accessible way to grow potatoes is in  large containers or tubs like this one here.

This could be put any anywhere: on a terrace,  on a balcony, or indeed any spare corner, which makes growing them this  way very accessible indeed. This is a generous size at 30 liters  or 8 US gallons, which means there's plenty of room for the tubers to grow  and they won't dry out as quickly. And today we'll be planting a determinate  variety of potato called 'Swift', but this method is going to work  well for indeterminate potatoes too.

Let's start by preparing our growing  medium, and for that I'm using some sieved garden compost and, boy, is  this stuff beautiful! It's so crumbly. I'm also going to add in some old  potting mix that I'm just going to reuse.

And then to bulk it all out some  standard fresh potting mix as well. Now this three-way split saves on  that new potting mix because it is quite expensive stuff, so it  makes it a bit more economical. And then to finish it off just to give  it a further boost just a really small handful of general purpose organic fertilizer,  and I'm using some blood, fish and bone here.

You can also often find organic potato  fertilizers tailor-made for this, but this stuff should do just fine. And now I've got to give it a really good  mix up so everything is evenly combined Now pot-fill time. And to start I'm just going to fill a container about one third full  with our mix here.

. . that should do it.

And now two seed potatoes are  going to go in. . .

there we are. And now I'm going to fill it with  another third of our mix, carefully so we don't topple over our seed potatoes and  they're still still facing the right way up. And now this time in go another two seed potatoes,  and this time I'm going to set them at sort of right angles like that, so when the foliage  grows it's not kind of on top of each other.

With our two potatoes in I'm going to cover  them back over right the way to the top. I got the idea for growing them like this  from Tony O'Neill, and what I love about this idea is that, remember we're growing determinate  potatoes and they form in kind of single layers, so by planting two potatoes here and then  two here we've got two layers of potatoes. That way we're getting much more in  the space we have available here.

Now if I was to grow an indeterminate  variety in a bucket like this, well I could get away with just  planting them at the bottom here because I know that as they grow they'll  form tubers all the way along like that. Let's just finish it all off now by  giving them a good drink of water. Now later on I will be adding a mulch on top  of either straw or dried grass clippings, and what that will do is help to  insulate it to keep it warmer, and then cooler as the weather gets hotter.

And it will also help to retain valuable moisture. Now it is crazy early to be  planting potatoes like this. Potatoes are usually planted in early to  mid spring, and not nearly this early.

That said, if you have a protected  structure like a greenhouse or you live in a warmer climate then planting  this early. . .

well why not give it a try. Now I'd better get these moved inside. Wherever you are growing them - even in a protected structure like  this - watch out for frosts.

If a heavy frost threatens then pick up your potatoes and move them somewhere  even warmer like, say, a garage. Or perhaps cover them with something like a fleecy row cover to insulate  it. Potatoes do not like it cold.

Now with this super-early start  in this protected structure I reckon I can get my potatoes up to two  weeks earlier than potatoes outside. We'll see, and I'll be sure to  let you know in a future video. It's just too cold to be planting them out here.

There's probably still another month to  go until the frost risk is manageable. I'll be planting, when the time comes, some more  first early potatoes here and some maincrops. In the meantime, the soil is nice and prepped with a good layer of compost ready to  receive those chitted potatoes.

When it's time to plant them I will space  my seed potatoes about 14 to 16 inches, which is 35 to 40cm apart,  in a grid-like formation. And then I'll simply dig a hole aiming for  a hole of 6 to 8 inches or 15 to 20cm deep, pop my seed potato in, and then  just cover it over, nice and easy. That spacing is ideal for early to midseason  varieties, or first and second earlies.

For my late season or maincrops,  they'll be spaced a bit further apart, at 18 inches or 45cm between the seed potatoes. That allows the extra space for these  guys to form their bigger tubers. If you're unsure how many potatoes  will fit in the ground you have, well our Garden Planner can help with  that to get the spacings just so.

You can also plant potatoes in trenches cut  into the ground, or even underneath straw. And if you'd like to know more  about either of those techniques, I'll link to videos on them down  in the video description below. For in ground or in bed potatoes there's then the question of whether to hilll  or 'earth up'.

Do they need it? Determinate potatoes need  nothing more than a mulch, and I will be using a combination of  grass clippings, straw and dried leaves. Now if you remember they form  their tubers all in one layer, so all we really need to do is make  sure that any that do poke proud of the soil surface are covered and shaded  from the sun so they don't turn green.

Indeterminate potatoes on the other hand produce  those tubers more in a vertical formation, so the more space we can give the tubers to  grow in, the bigger and better our harvest. Now this is where hilling or earthing up comes in. Just use a hoe to draw up  the soil around the stems of the plant to create more volume  of soil for the tubers to grow into.

You will only need to do  this once, possibly twice, until you can earth up no more or the foliage  above closes in and creates shaded conditions. Try to earth up in the morning if you  can, when foliage will be fuller with water and so standing more upright, which  will make the whole job a lot easier. And in all cases make sure you plant  your seed potatoes nice and deep, cos that will give more room  for your tubers to develop.

Wherever and however you're growing your  potatoes, keep an eye on moisture levels. Now in most cases there's plenty of rain to keep  them growing nicely, but they may need watering in dry weather and container potatoes  especially will need regular watering. Aim your water at the base of  plants to avoid wetting the leaves, which will create humid conditions and  the perfect conditions for disease.

Now I will need to keep a special  eye on my container potatoes, cos water will evaporate and get used  up very quickly in that smaller space. The walls of the container are also black,  which can warm up very quickly on hot days. So if that does happen I might move  my containers into the dappled shade.

Potato blight, or late blight is perhaps  the biggest concern for potato growers, but there are a few simple strategies we  can deploy to avoid this fungal disease. The first is to grow early maturing varieties  that will be out of the ground by midsummer, before the disease typically appears. The second strategy is to grow  blight-resistant varieties, which is why I'm growing 'Sarpo Mira', one  of the most resistant varieties of all, although there are plenty of other  blight-resistant varieties available.

And, of course, be sure to aim water right at the  base of plants so you're not wetting that foliage. If blight does strike, well don't panic. Just  cut all the foliage back to ground level and then leave everything as it is for about three weeks  so that any spores still lurking can die off.

And then go ahead and lift up your potatoes  and eat them up as soon as possible. You can add blight-infected foliage to your  compost heap, but just make sure to cover it with other materials so the spores don't  kind of blow away and out into the garden. Which brings us nicely onto  harvesting more generally.

I like to harvest my early  potatoes while the foliage is still very much green and lush and  the plants are coming into flower. Container potatoes can just be tipped  out and then the tubers gathered up. But for in-ground or in-bed potatoes extra care is needed to avoid spiking those precious  potatoes with the tines of your fork.

Start carefully from the outside and carefully  work your way in towards the center of the plant. I like to grab the foliage, if it's still  intact, and holding it up get the fork in there and underneath, and gently rock it back and  forth to loosen the plant and then pull it up. And then I can easily go ahead and  gather those delicious lovely tubers.

Now do handle them with care, because you don't want to bruise them,  and enjoy them as soon as possible. Late season or maincrop potatoes are  harvested later on in the summer as the foliage is beginning to yellow and die back. Before you harvest them, maybe two  to three weeks ahead, stop watering.

This will encourage the skins  to thicken and toughen up, which is what we want if we're going to store. Then cut back the foliage, if there's lots  of it, so you can see what you're doing. Then get in there and dig up the potatoes.

Once you have, just leave them on the soil surface for a couple of hours to dry  off before gathering them up. Now you can store them in any  breathable sack - something like this, or perhaps a hessian or burlap sack, for example. Now you can store potatoes, but only  perfect, blemish-free potatoes.

Any that have got accidentally speared  by your fork, that are burrowed into, bruised or perhaps green. . .

store those  separately and use them up as soon as possible. I like to store my potatoes in here. It's  cool but frost-free, well ventilated and, crucially, it's dark, so there's  no danger of greening potatoes.

In there they will store for a  good few months - well into winter. Now do you want more? Well, please  dig into our potato playlist next.

I'll catch you next time.