Top Of The Crops - Beetroot

Growing Beetroot in a Polytunnel

Beetroot is a crop that is ideally suited to polytunnel growing. It is a plant that does not take up a huge amount of space and it has a long growing season, especially when it can be grown undercover. Practice successional planting and preserving techniques and you can be enjoying beetroot for much of the year. This is a far more versatile vegetable than you might imagine and can be used in a number of different ways. Home grown beetroot is delicious and bares little resemblance to the shop-bought stuff, doused in vinegar.

Beetroots will grow well in a polytunnel and will do well when planted alongside onions and brassicas. There is evidence that suggests that runner or French beans and beetroot may stunt each others growth and should be kept apart, which is worth bearing in mind when planning your polytunnel layout. Two secrets to growing:
1. Beetroot has a natural inhibitor to germination. Soak seed in tepid water for half an hour before sowing.
2. Avoid growth checks and don’t allow globes to get too large.

Seed Sowing

Beetroot is not particularly fussy when it comes to growing conditions but it does require a fertile growing medium. Add compost to your soil before sowing the seeds, which you can do any time between March and July. In order to improve the rate of germination, you can soak seeds for half an hour in tepid water prior to sowing to remove the natural germination inhibitor that is present on the seeds. Sow thinly and to a depth of around 1-2cm.

It is important to water consistently and it is a good idea to mulch with a good organic fertiliser. One that is high in nitrogen will boost foliage growth but take care not to provide too much nitrogen or the plants can create leafy growth at the expense of the root formation.


Mature beetroot can be harvested between June and October. As your beetroot grow you will have to thin them to leave the remaining plants room to grow to maturity. The good news is that you can eat the beetroot that you thin. These baby beetroot are fiddly to deal with but boil them, mud and all, in a saucepan of water and they will pop right out of their skins and be perfect in a spring or summer salad.

Beetroot are at their tastiest when they are around the size of a golf ball or a little larger. You can wait until they reach tennis ball size but should not wait too long or they can become tasteless and woody. Thin and eat alternate beetroot as they grow and do not throw the leaves away! Beetroot leaves are delicious to eat and are a secondary crop that should not be wasted.

To store beetroot, twist off leaves (do not cut them off) and place to roots between layers of dry potting medium in a box. They should also keep in the ground of a polytunnel throughout the winter as long as they are not subjected to a hard frost, which can damage the roots. Protect with horticultural fleece and lift the roots as needed over the winter months.


Early crop to be ready late May sow both resistant varieties in March under cover.
Could sow three seeds to a pot to plant out later.

< Back

Swipe to scroll through tabs

About First Tunnels

We’re a close-knit bunch of skilled professionals who take an enormous pride in the quality and versatility of our products, But we’re enthusiasts too - we use our own products, and that means we’ve introduced lots of improvements and innovations over the years…based on first-hand everyday practical experience. We work hand-in hand with top growing experts. We even have our own allotment for some seriously hands-on gardening, often accompanied by communal summer and winter barbecues because all work and no play would be very dull!

Polytunnel Community

Reviewed by you, Followed by you, Liked by you and listened to by us. We have a strong online polytunnel community, 35k Facebook Fans, 10k Twitter Followers and over 3m YouTube Views. Our community of dedicated, passionate Polytunnel gardening friends, love to share their sowing tips, growing hints and harvesting secrets with each other. But more importantly for you, as a customer or a potential customer, you can post your comments in all their glory or gory details. Come and join the Polytunnel family.

Construction Help & Advice

Our six man construction team has a wealth of polytunnel construction knowledge and are more than happy to share tips and advice with any of our customers. Many of the team have been quite literally 'hands on' developing the First Tunnels vast array of construction videos and in depth instruction guides. Our construction team are available to answer your questions and help in whatever way they can. Simply call 01282 601253 on week days between 9am-5pm...PLUS weekend cover on 07801 601253, between 9am-5pm.

Frequently Asked Questions

We are proud of our products and the time that we have put in to making sure that all our products are first class. We understand that purchasing a polytunnel is a considerable investment, and whilst we have lots of help and advice on this site, Facebook, YouTube, Twitter and blog pages many people like to compare and contrast before they commit their hard earned cash to buying. To this end we have compiled a list of the most common questions and provide 10 top reasons why First Tunnels Polytunnels is the top choice.

Getting Growing

Part of the fun of owning a polytunnel is picking the brains of people who really know how to make the most of the real growing potential. So we're making it easy for you...with some of the best brains in the business! This site now includes features, produced exclusively for First Tunnels by Andy McKee and Mark Gatter - best-selling authors of 'How to grow food in your Polytunnel' and 'The Polytunnel Handbook'. We also have videos from BBC’s Gardeners’ Question Time presenter, Paul Peacock. We also have a host of growing guides from Sam Youd, presenter & judge for the Royal Horticultural Society & Tatton Park Head Gardener.

Other Useful Stuff

What better way to learn about company dependability, product quality and customer service than to hear it straight from other consumers? By giving customers the opportunity to share their First Tunnels shopping experience, we believe this is the best reflection of our companies’ product and service. To help reinforce credibility, popularity and reputation, we have subscribed to not one, not two...but THREE independent review companies. We value all feedback, good, bad or ugly and hope to build a long lasting relationship with our customer, through our high quality products and friendly service, to ensure they do not hesitate to order again and again with First Tunnels in the future.