It’s potato planting time! If you’d like learn how to grow potatoes in bags, this guide covers everything you need to know.
Growing potatoes in bags
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.
The best potatoes to grow in bags
Before you start planting potatoes in bags, it’s worth understanding a bit about the different types you can grow.
There are three main varieties of potatoes for growing. The name of each reflects 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 are ready for harvesting from late July to September.
What month do you plant potatoes in bags?
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 are ready to harvest around 10 weeks after planting.
- Second early potatoes are ready to harvest around 13 weeks after planting.
- Maincrop potatoes are 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 potatoes in bags in April or May, it’s a good idea to go for a first early or second early potato 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 are 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
It’s a good idea to let your seed potatoes sprout before you plant them. This gets the growing process started sooner, which gives you an earlier harvest and can also increase yield.
To encourage your seed potatoes to sprout, you need to put them in a cool, frost-free, light 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 have grown shoots.
The shoots should look nice and strong, and be reasonably short, with a green or pink colour to them. If your seed potatoes don’t get enough light they will produce long, white shoots that are more fragile.
How to grow potatoes in bags
When your seed potatoes have 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.
To limit the use of plastic, you can grow potatoes in hessian sacks (also known as burlap sacks), or buy specially designed *potato grow 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, make some holes in the bottom for drainage before you start.
Fill your potato grow 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 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.
How to plant potatoes in bags
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. Repeat this process until you’ve almost 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 all there is to growing potatoes in bags. 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 for a Christmas harvest you need to plant your seed potatoes in late summer. 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. This video also covers growing potatoes in bags:
More grow your own inspiration
For more grow your own ideas, you might like to check out these posts:
Are you having a go at growing your own potatoes this year? Do you have any tips on how to grow potatoes in bags or containers?