Growing Potatoes in Grow Bags from Planting to Harvest

Growing potatoes at home in grow bags is a fantastic way to start growing your own potatoes at home. It’s one of the best first steps into growing your own produce because it is a relatively easy process from start to finish, that’s easy to get going. All gardeners of all skill levels and experience levels can have a go. The particularly great thing about grow bags is that you don’t need to plant in the ground or have a large garden or even a garden at all; they can be grown on balconies, porches, patios, anywhere where space may be at a premium. You buy the bag, fill it with compost and off you go. With some extra steps of course, but it is quite easy with a little preparation and effort.

Potatoes are one of the most beloved vegetables in the UK. As a nation we can’t get enough; it’s our most loved vegetable. We consume millions of tonnes every year in all forms from baked potatoes to chips, mash and crisps. It’s easy to see why they are popular among gardeners too. While most people are familiar with the varieties available in supermarkets, growing your own gives you access to a much wider range, including some unique and heritage types with very nice flavours.

Growing potatoes in grow bags is a great option, especially if you’re short on space. They don’t require a dedicated garden plot, making them perfect for patios, balconies and other small spaces. Another big advantage is that harvesting is incredibly easy, simply tip out the bag and collect your potatoes. Good-quality bags can also be reused for several seasons, making them a practical and cost-effective choice.

Before planting, consider what type or types of potato you are after. Then, get the correct seed potatoes for the variety you’re looking for. Maybe it’s salad potatoes, or maybe you want great big jacket potatoes, or potatoes that make great chips. Whatever the variety it will be seed potatoes you need to start with, as these are certified virus-free and are grown specially for growing potato crops.

Potatoes are classified as being either earlies or maincrops. Early varieties of potato are ready to harvest much sooner than maincrops and are what we call ‘new’ potatoes. You may have noted that new potatoes are smaller, and this is why. Typically, they will have a smoother waxier texture. Maincrop varieties however are left a lot longer. They produce a larger harvest and are generally bigger potatoes.

There are countless varieties of potatoes to choose from, each with unique characteristics. This list below is just a small selection of the many varieties you can choose. We have focused more on earlies because they’ll grow well in the smaller space of your grow bag (versus in the ground), and you’ll get a nice balance of size and number of tubers (potatoes) at the end of the season:

• First early potatoes take roughly 80 days after planting to mature and should be ready to start harvesting in mid-June.
• Second earlies take around 100 days after planting to mature and will be harvestable around mid-July.
• Maincrops take the longest time to mature, at roughly 130 days or around mid-August.

Weather and growing conditions will also be factors to consider. If you are in a colder region of the UK on average, it might pay to wait a bit longer to plant.

Now you know some more about potatoes you’re ready to get started growing your own at home in grow bags. It pays to know what to do in advance so read through our guide, and then when you’re ready to go, get started! Remember, you’ll be starting off from the specially prepared ‘seed’ potatoes mentioned earlier. You can generally buy seed potatoes from late winter in our garden centres.

When it comes to growing your own fruit or vegetables, preparation is the key to success. Before starting anything, gather some necessary items and materials:

• Potato Grow Bags

You only need one to get going but typically you can buy them in bundles of two or three. One large grow bag of about 40 or 50 Litres will allow you to place several seed potatoes which should spawn a few plants for a good yield.

Once you have gathered what you need, it’s time to chit your seed potatoes. Chitting helps seed potatoes sprout before planting, which speeds up growth once planted and increases yields. To chit potatoes, place them in a cool, bright area, such as a north-facing windowsill, and let them sprout for four to six weeks. Arrange them in trays or egg cartons with the sprouting end facing up. By late January or early February, the shoots should be around one to two centimetres long, making them ready for planting.

When choosing the spot for your grow bags whether in the garden, patio or balcony, try to opt for an open position, in full sun. Don’t have it anywhere it could get damp or wet as this can lead to disease in your crop. Ensure that the drainage holes in the grow bag are not blocked too. If growing inside of a greenhouse, you can start off any time from February onwards. All you need to ensure is that the greenhouse is frost free and has a daytime temperature over 10°C.

Around late March/early April it will be time to plant your chitted seed potatoes. Fill the grow bag about one-third full with compost and loosen it with a fork to ensure good drainage. Place the chitted seed potatoes sprout-side up, spacing them evenly. Cover them with another 20-30 cm of compost and water thoroughly. As the shoots grow, continue adding more compost to cover them, a process known as earthing up. This encourages strong root development and prevents the potatoes from being exposed to light, which can turn them green and inedible.

As the plants grow in the bags, top up with more compost once the shoots are above soil level by roughly 15cm (half a ruler). If the weather is dry or particularly hot, keep the plants well-watered. This is even more important for first and second earlies. Depending on the type of feed/fertiliser you have, feed every other week or as instructed. Continue to keep an eye on things over the weeks until you approach harvest time. Rest assured that most of the work has been done at this stage.

When it comes to harvesting, timing will depend on the variety you’ve planted. First earlies are usually ready when the plants start flowering, while second earlies can be harvested a few weeks later. Maincrop potatoes should be left for at least two weeks after the foliage dies back to allow their skins to set. Cut down the stems with secateurs to just above soil level as the leaves wither. Leaving them to set makes them suitable for long-term storage.

Early varieties should be enjoyed within a few weeks, while maincrop potatoes can last for several months if stored correctly. Keep them in a cool, dry, and frost-free place, ideally in thick paper sacks to block out any light. Avoid washing them before storage, as moisture can encourage rot. Periodically check your stored potatoes and remove any that show signs of spoilage.

Potatoes can face some challenges, but with proper care, most issues are minimal, especially when using grow bags. Here’s what to know:

• Potato Blight

A fungal disease with no cure, blight causes yellowing leaves with dark patches and rots tubers. Grow resistant varieties or cut plants down at the first sign of infection to protect the potatoes, then harvest them quickly.

There you have it. Now you know how to tackle growing potatoes at home in grow bags. When you follow our guide through and complete your own harvest, you’ll wonder why you didn’t try it sooner. Most seed potatoes and plants produce a bountiful crop, so you’ll have plenty to enjoy over the growing season. Will you mash, boil, make chips? Do it all? Why not?! And once you’ve grown your first chosen variety all the way to harvest, why not try get some more grow bags and try some others next year? Nothing beats the satisfaction and taste of homegrown produce.