It’s potato planting time!
I think it’s impossible to beat the taste of homegrown new potatoes, and they’re not difficult to grow at all. In fact they’re a brilliant veg to grow with kids; they’re nice and chunky to handle when planting, the kids get to pile soil on them as they grow, and harvest time is basically a treasure hunt as all those lovely spuds are unearthed!
If you’ve got lots of room in the garden or at an allotment, you can of course grow potatoes in rows and get a really big crop, but don’t be put off if you don’t have a lot of space. You can grow potatoes very successfully in a container, and using this method is perfect for small gardens or your first efforts at grow your own. Here’s how to grow potatoes in bags.
Different types of potato to grow
Before you do anything else, it’s worth understanding a bit about the different types of potato you can grow. Potatoes for growing are usually split into three varieties, each named according to the time of year that you plant and harvest them.
- ‘first early’ varieties will be ready to harvest soonest – around June. First earlies are what we traditionally think of as ‘new’ potatoes.
- ‘second early’ varieties are also ‘new’ potatoes, but they take a few more weeks to grow.
- ‘maincrop’ varieties produce potatoes that are best suited to baking, mashing and roasting. They take the longest amount of time to grow, and will be ready for harvesting from late July to September.
What month do you plant potatoes?
March is traditionally the most popular time of year to plant potatoes. Having said that, if you choose the right variety you can plant them in April and May and still have a crop before autumn.
How long does it take to grow potatoes in a bag?
The amount of time it takes for your potato harvest to be ready is mainly influenced by the variety of potato you choose. The weather also plays a part.
- First early potatoes will be ready to harvest around 10 weeks after planting.
- Second early potatoes will be ready to harvest around 13 weeks after planting.
- Maincrop potatoes will be ready to harvest around 20 weeks after planting.
It’s really up to you which variety you choose; just decide when you’d ideally like to harvest your potatoes. Once you know this, you can work out which variety is the best option. You can also check the growing times on the bag.
If you’re planting in April or May, it’s a good idea to go for a first early or second early variety which takes less time to grow.
Once you’ve decided which type of potato you’d like to grow, you’re ready to buy your seed potatoes.
What are seed potatoes?
Seed potatoes are potatoes that have been grown with the specific purpose of being replanted to produce a crop of potatoes. The little shoots that sprout from each potato is where the crop will develop.
It’s definitely a good idea to buy seed potatoes as opposed to potatoes which you’ve bought to eat that have sprouted, because seed potatoes are guaranteed to be free of viruses.
How to make seed potatoes sprout
Your seed potatoes need to have sprouts before you can plant them. To encourage this, you need to put them in a cool, dark place; this is often referred to as “chitting”.
You might find that the seed potatoes you’ve bought are already sprouting, this is fine and has actually saved you a bit of time! If not, pop them into a plant saucer, shallow tray or old egg box until they look like this:
How to grow potatoes in bags
When your seed potatoes are sprouted, you’re ready to plant.
All you need is your seed potatoes, some compost and a bag. You can use any large, strong plastic bag to plant them in, for example, an empty compost bag. Bin bags are a bit too flimsy. If you’d like to limit the use of plastic, you can buy specially designed *potato planting bags, like the one we’ve used in the picture below. These bags can be reused year after year; as you can probably see ours is a bit faded and battered, but it’s still going strong after a few years of use.
You can also plant potatoes in pots, if you happen to have any spare.
If you do use a plastic bag, you need to make some holes in the bottom for drainage before you start.
Fill your bag about a quarter full with compost; you can roll down the top to make this easier.
How many potatoes can I plant in a bag?
The number of potatoes you can grow in a bag will obviously vary depending on the size of bag you’re using. For the bag shown in the pictures, I plant 2-3 seed potatoes, depending on how big the potatoes are.
Don’t be tempted to plant too many potatoes in your bag. This will just make more plants compete for the same amount of nutrients, and won’t give you a bigger harvest.
Planting seed potatoes
Next, position your potatoes evenly in the bag, with the majority of their sprouting shoots pointing upwards.
Cover the potatoes with another layer of compost, then give them a thorough watering. And that’s it! Now you just need to water them regularly and let them get on with growing, until you see leaves appearing on the top of the compost.
Do potatoes need full sun or shade?
Potato plants grow best when they have access to plenty of daylight. A sunny spot is great, but they will also tolerate partial shade.
Earthing up potatoes
When your potatoes have produced leaves, it’s time to earth them up. This is simply adding more compost to cover them up again. You need to do this for two reasons: to prevent the growing potatoes turning green and poisonous, and to increase your crop by encouraging more potatoes to grow on the buried stems.
Unroll the top of the bag as you add more compost. Keep repeating this process until you’ve pretty much filled your bag with compost. At this point you can leave the plants to grow and flower – but keep watering them regularly.
How do I know when my potatoes are ready to harvest?
Your potato plants will produce flowers. They are ready to harvest when the flowers start to die off.
To harvest your potatoes, pull the stem of the plant out of the compost. Gather up any potatoes that are still attached to the roots, then check the compost for any that have been left behind.
You don’t have to harvest all of your crop in one go. You can dig up a few potatoes at a time, coming back for more when you need them.
If you’d prefer to dig all your plants up in one go, that’s fine too. Just make sure you store your potatoes somewhere cool and dark until you’re ready to use them. This will keep them fresh and prevent them from sprouting. You can buy *potato storage bags which are designed specifically for this purpose, but a container with a lid or a cloth drawstring bag will work well too.
And that’s it: follow these few easy steps and you’ll be enjoying amazing homegrown potatoes this summer. They really do taste so much better than shop-bought!
Growing new potatoes for Christmas
New potatoes are very much a summer treat, but it’s perfectly possible to grow potatoes in bags for Christmas lunch too!
The method is just the same, but you’ll need to plant your seed potatoes in late summer for a Christmas harvest. Garden centres usually have seed potatoes for sale at this time of year that are specifically suited to this project. You will need to protect your plants and harvest from frost, so move your bags into a sheltered spot or greenhouse when temperatures start to drop.
If your potatoes are ready a bit too early, you can dig them up, re-bury them in soil, and put them in a frost-free place until you’re ready to eat them. It’s not a great idea to leave them in the ground, as they’ll be vulnerable to damage from frost, slugs and general wet conditions. You can also dig them up and store them in the fridge, or in a bag in the shed or garage, but you’ll lose some of the lovely flavour and texture this way.
If you’re interested in other ways to grow potatoes, take a look at this post on how potatoes are grown. You might also like to check out this video which covers growing potatoes in bags:
More grow your own inspiration
For more grow your own ideas, you might like to check out these posts:
How to grow a windowsill herb garden
55 easy grow your own tips, ideas and resources
Will you be having a go at growing your own potatoes this year? Do you have any tips on how to grow potatoes in bags or containers?
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They are super to grow, I do not have a large space for gardening and I found that this is the very best and easiest way to grow potatoes. I encourage anyone who likes gardening and has small space try this. You can reap the joy of planting and eating your own food.
That’s great to hear Karen, it really does work doesn’t it! Hope you have a bumper harvest this year 🙂
Great post, and great pics. I do this too. Works every time. The only cautionary tale I have is don’t plant before the frosts are over UNLESS you have some fleece (or other frost protector) to put over bags. I’ve been caught out this last week with just that very thing.
Ah that’s a great tip – thanks! We have frosts forecast this week so I’m definitely going to give our bags some protection, just in case. Hope you haven’t lost too many plants.
How many potatoes will grow when you only plant 3 potatoes?
That really depends on how big your container is and the variety of potato you choose, but in my experience you can expect to harvest around ten potatoes for each one you plant. The process of earthing up encourages more potatoes to grow on the buried stems, so it’s well worth remembering to do this regularly.
We would love to try your potato in a bag idea! But we are wondering where to keep the bag. Do you keep it indoors or outside? Which leads me to the next question of what time of year do you plant the potatoes? It is currently the month of March and we live in Minnesota. We would appreciate any advice you could give!
Thank you so much!
Potatoes are an outdoor crop, so you should definitely keep the bag outside. Potatoes are usually planted in early spring for harvesting 3-4 months later, so the next few weeks would be ideal for getting started where you live. Happy planting!
I’ve not tried growing them in a bag before, I may give this a go this year!
Ooh give it a go, it’s really easy and very low maintenance!
What if my potatoes don’t flower?
Not all potato varieties flower, and you can also have a good crop of potatoes without any flowers at all. I would wait until the growth looks like it’s starting to die back, then carefully check for potatoes – if you find very small ones it’s probably worth waiting a bit longer before harvesting.
hello Catherine, first can I say love your site you explain things that I understand, Im trying out for the first time growing veg in my back garden ive grew tomatoes, runner beans, were great now im trying to grow potatoes in growing bags the plants are looking healthy and green but still no flowers on the plants? how long do you think I should wait to see if there is any potatoes under the compost? How long does the flowers comes on the vines? Catherine I know this isn’t about potatoes but I would like to grow mushrooms in growing bags, can you tell me how easy to grow them? people have told me its hard to grow mushrooms out doors? if this is true could I grow mushrooms in growing bag in my spare room where its nice and warm? thank you so much catherine
It sounds like you’re really enjoying growing your own! Not all potato varieties flower, so I think the best thing to do is wait until the foliage starts to turn yellow and die back, then check carefully for potatoes. If you know which variety of potato you planted you can also look up the typical time they take from planting to harvest. I’m afraid I haven’t ever grown mushrooms so I’m not much help with that one! I did find this article over at Thompson & Morgan which might be useful though: https://www.thompson-morgan.com/how-to-grow-mushrooms Happy planting 🙂
Hello like to try this with some ikea bags how many wholes I have to punch?
I would say around 6-8 holes would provide enough drainage – hope you get a bumper crop!
Hi. Do I have to use black bags? Is the size of a 12.5kg rubble bag right for 3 potatoes or does it need to be bigger?
Compost. Multi one or does it HAVE to have soil as well.?
Stay safe. Kind regards
Pauline
You don’t have to use black bags, any plastic bag will do as long as it isn’t too flimsy. 3 seed potatoes sounds about right for the bag you describe. Multi-purpose compost is ideal, you don’t need any soil – just the compost. Hope that helps!
Thank you. So I can use see through rubble bags?
Kind regards
Ah sorry I didn’t realise you were asking about clear bags. I don’t think clear plastic is a good idea, because you need to keep the growing potatoes away from the light. If they are exposed to light they will turn green and be inedible. So if you can find anything that isn’t clear to hold them that would be best.
Tried this year with advice from some big name nurseries to fill the bags from the start and plant sets half way down.
What a disaster, just havested after 12 weeks ‘Royal Kidneys’ and there is practically no crop
Gutted
Oh that’s a real shame – how disappointing! I’ve never tried filling up the bags from the start, and based on your experience I think I’ll stick to the usual method. Hope this doesn’t put you off having another go though.
I live in Spain, I only have a small east/south/west balcony so a lot of sun nearly all day.
I have a strong supermarket bag, would that do ? Could stand it on a tray to catch any excess water. It’s June now so maybe too late for this year.
I think a supermarket bag would be OK as long as it isn’t see-through (if the growing potatoes are exposed to the light they turn green and inedible) – make sure you poke some drainage holes in the bottom. You can still plant seed potatoes if you’ve got some, don’t wait too long to do it though!
Hi, decided to try and grow potatoes for Christmas. It’s only been three weeks and I have already had to earth up to the top, the shoots were coming up quickly! Does that sound ok? Or will they be ready much earlier than Christmas?? Thanks
I think you’ll be fine – if your potatoes are ready a bit too early (they’re ready when they have flowered and the foliage starts to die back), you can dig them up, re-bury them in soil and put them in a frost-free place until you’re ready to eat them. It’s not a great idea to leave them in the ground, as they’ll be vulnerable to damage from frost, slugs and general wet conditions. You can also dig them up and store them in the fridge, or in a bag in the shed or garage, but you’ll lose some of the lovely flavour and texture this way. Hope you get a bumper harvest!
Thank you! Sounds like great advice 🙂