Sky Gardening Challenge 2026

Learn how to grow plants in small spaces with our short video tutorials, created in collaboration with Plant CIC.

From choosing the right plants to making the most of your balcony, prepare to get your hands dirty in these expert-led guides that will help you start your greening journey with confidence.

• Join Andy for our tutorial on Wild about Wildlife
• Join Grace for our tutorial on Sustainable Solutions
• Join Rachel for our tutorial on Balcony Basics
• Join Grace for our tutorial on Food Growing
• Join Rachel for our tutorial on One Pot Power

This document provides minimum essential safety considerations, is not exhaustive, and does not replace landlord and/or building manager, insurer or fire authority requirements.

If you live in a flat and want to garden your balcony, window box or ground-floor space, it is important that you:

• Get relevant permission from your landlord before undertaking the challenge. Many housing providers allow ‘managed use’, which means you may be able to use the space for gardening; there may be certain rules you need to follow, which could differ from housing provider to housing provider. Some housing providers may have a ‘zero tolerance’ approach to balcony usage or ‘sterile balcony’ policy, which would prevent you from using it for gardening. In this case, you could not take part in the challenge, but you can focus on houseplants you can grow in your flat!
• Check your Buildings and Contents Insurance policies to check if there are any restrictions.

If you get permission to garden your flat’s balcony, window box or ground-floor space, it is essential that you:

• Comply with any requirements your landlord/management company specifies.
• Don’t make material alterations (e.g. structural alterations) to your flat or balcony when gardening, without first getting consent from your housing provider and any necessary approvals from building control.
• Do not use fire under any circumstance.
• Keep all fire escape routes free of obstructions, such as plant pots. This could include common areas such as stairways, deck walkways/linking balconies, or roofs which form part of a fire escape route for yourself and/or others.
• Don’t do anything through gardening that would interfere with the fire protection measures for your flat or building (e.g. fire doors, signage), or impact on the compartmentation of your flat, i.e. cause fire to spread more easily from one flat to another or into an escape route.
• Don’t use, or store, combustible materials for gardening on a balcony (e.g. wooden trellises, petrol gardening equipment, hazardous chemicals, gardening waste etc). Dry compost and dry plant material (e.g. dead plants) can be flammable, so it’s important to keep your plants healthy and well-watered; in the event of a fire, they could encourage fire to spread to a neighbour’s flat. Do not attempt to extinguish any flame or cigarette in plant pots as it will be at risk of igniting.
• Check the weight restrictions for your balcony with your housing provider, and make sure you don’t exceed them. Lightweight containers and lightweight roof garden soil can help keep weight down.
• Ensure plant pots and heavy items are kept away from the edge of the balcony and do not hang over the external side of the balcony due to risk of falling and causing injury to anyone below.
• Avoid positioning pots, planters, or trellises in such a way that they form steps up the balcony rail/parapet, or create trip hazards.
• Ensure that any free-standing structures such as plant pots, stack planters and free-standing arches are robust and weighted down to avoid them becoming damaged or hazardous in high winds. Avoid placing planters or other items on the balcony parapets/rails. If railing planters/hanging baskets are permitted by your management company and/or landlord, keep them on the inside of your balcony.
• Do not lean over or sit on balcony walls or railings in order to garden, or stand on balcony furniture, ladders or stepladders due to risk of falling over the balustrade.
• Ensure any electrical equipment used for gardening (including fairy lights) is in good working order, suitable for outdoor use and not left unattended when switched on. Avoid wiring it directly into your flat or using extension leads.
• Use drip trays, saucers or trays underneath plant pots to prevent water overflowing from plant pots and dropping onto balconies below or damaging the structure of your balcony. Make sure that drain outlets are not covered and water flow into them isn’t restricted.
• Follow instructions and warnings on gardening products and tools.
• Be aware that some plants can be hazardous to people or pets if touched or consumed. Check plant labels for toxicity warnings (sometimes stated on label) and take necessary precautions.

1 June: National Trust’s Sky Gardening Challenge Competition opens

16 August: Competition closes

By 4 September: Finalists contacted

10-12 and 18-19 September: Judges visit finalists

By 9 October: Prize winners will be notified they have won a prize (but not their ranking) by either email or phone

17 October: A celebration event will be held where prizes will be announced

The competition is not open to National Trust employees, or project partners’ employees who are directly involved in the project.

To enter you must:

• Be aged 18 years old or over.
• Live in England, Wales or Northern Ireland.
• Live in a flat or apartment and have greened a private or shared balcony or walkway, outdoor window box, or outdoor ground floor space attached to your flat or apartment.

There is a limit of one entry per household. You can enter on your own behalf, or as a named individual on behalf of your household.

You do not need to have signed up to or have engaged in other elements of National Trust’s Sky Gardening Challenge in order to enter the competition.

You must submit your entry between Monday 1 June 2026 and Sunday 16 August 2026 23:59 (the Closing Date). Entries received after the Closing Date will not be accepted. Entry can be made either online or by post. We cannot take responsibility for entries that are corrupted, lost, delayed, mislaid or damaged in the post.

Online entry

Entry is via an online form, which is available here. You will need to upload either:

• A video of your greening project (maximum length of 5 minutes), or
• Photographs of your greening project (a maximum of 5) and commentary (a maximum of 500 words).

Postal entry

You may submit printed photographs and a written commentary by post alongside a completed entry form.

To enter by post:

• Request a paper entry form by writing to skygardeningchallenge@nationaltrust.org.uk or calling us on 0344 800 1895.
• Send your completed paper form, printed photographs of your greening project (a maximum of 5) and written commentary (a maximum of 500 words) by post to arrive no later than the Closing Date to “National Trust’s Sky Gardening Challenge, National Trust, Heelis, Kemble Drive, Swindon, SN2 2NA”.
• We cannot accept digital entries or videos by post.
• We will not return postal entries.

The competition is divided into five categories, which are listed below. Choose a category that best reflects your greening/garden (although note restrictions below). The category is in bold with suggestions for inspiration following.

• One Pot Power – proving that one pot is all you need to make something brilliant. Tell us about your one-pot growing story and the impact it’s made on you, and the environment.
• Wild about Wildlife – using your balcony or window box to support urban nature and pollinators. Has your high-rise hangout encouraged urban wildlife such as bees and birds to your balcony? Tell us who you’ve met at your window.
• Food Growing – seeing how much you can grow to eat on your balcony or window box, from flat to fork. Whether it’s vertical veg, or high-rise herbs, edible gardens are lovely to look at and consume. Tell us your food growing story.
• Sustainable Solutions – hacks to green your balcony or window box the green way. What sustainable steps have you taken in your sky garden? From water-wise planting, peat free compost to using recycled materials, tell us what thoughtful interventions you have made throughout your greening journey.
• Greener Ground Floors – showing what is possible if you live in a flat with a ground floor space. How have you greened your small ground floor space? What approach did you take and why?

If you have greened an outdoor ground floor space attached to your flat or apartment, you may only enter the “One Pot Power” or “Greener Ground Floors” categories.

If you have greened a private or shared balcony or walkway or outdoor window box you may only enter the “One Pot Power”, “Wild about Wildlife”, “Food Growing” or “Sustainable Solutions” categories.

The competition will be judged by a judging panel including a National Trust judge and at least one independent judge. For the purpose of the judging process, your personal data will be shared with the judging panel.

Up to 15 submissions will be shortlisted, and finalists will be notified by 4 September by email or phone in accordance with the preference specified in their competition entry form.

On-site judging will take place between 10-12 and 18-19 September. Finalists will be allocated a short slot within one of these days where our judges will visit them to judge their entry.

Finalists must be present during the judging. If entrants do not wish judges to visit them or are not able to be present during the judging, they cannot be considered for a prize. If the finalist is unavailable, the National Trust reserves the right to shortlist another entrant.

Judging criteria

Entrants will be judged on the criteria listed below, which will carry equal weight:

• Choice of plants: Have you made conscious decisions about the best plants for your space (i.e. ones that will thrive in your conditions)? This might include choosing shade-loving plants for shady spots, or drought-tolerant plants for sunny spots.
• Use of space: However small your space, have you made the most of it when planning what to grow for your category? This might include things like choosing trailing/climbing plants, stacking planters, planting at different levels.
• Sustainability: Have you consciously made sustainable decisions when greening your space? This might include using peat-free compost, using recycled pots, thinking about environmental and ecological benefits of plants, or other activities to promote wildlife (e.g. bird feeders, bug hotels)
• Progression: This is all about 'trowel and error'! Whatever your starting point, have you tried new things when greening your balcony or window box, and what have you learned about it (or about yourself?)
• Overall impact: However small your space, what's the overall impact of your gardening? Does it reflect the category you've entered? What's its overall impact on you, other people, and nature?

Prize winners will be notified by 9 October if they have won a prize (but not their ranking) by either email or phone.

Prize winners will be invited to a celebration event on 17 October where prizes will be announced. Limited support with travel costs to the celebration event will be available to finalists on request. Those unable to attend will be contacted by 23 October 2026 to let them know which prize they have won and to arrange delivery of their prize by post.

First place(s)

There will be up to five first-place winners (i.e. one for each category) and each will win a prize bundle comprising the following:

• National Trust prize day out which includes: free entry to one National Trust property (valid for up to 2 adults and up to 6 children, one visit only, to be redeemed before 27 August 2027, some exclusions apply); and a £30 food and beverage voucher.
• £200 CJ Wildlife voucher for the Wild About Wildlife category; or a £200 gardening centre voucher for One Pot Power, Greener Ground Floors, Food Growing and Sustainable Solutions categories.
• A CEWE PHOTOBOOK of the finalists’ gardens, and a £50 photo printing voucher, courtesy of the National Trust’s photo printing partner CEWE.
• First place winner’s certificate.

Second place(s)

There will be up to five second-place prizes (i.e. one for each category) and each will win the following:

• National Trust prize day out which includes: free entry to one National Trust property (valid for up to 2 adults and up to 6 children, one visit only, to be redeemed before 27 August 2027, some exclusions apply); and a £30 food and beverage voucher.
• £50 garden centre voucher.
• A CEWE PHOTOBOOK of the finalists’ gardens, and a £50 photo printing voucher, courtesy of the National Trust’s photo printing partner CEWE.
• Second place certificate.

Highly commended

There may be one highly commended award per category. If so, each would win the following:

• National Trust prize day out which includes: free entry to one National Trust property (valid for up to 2 adults and up to 6 children, one visit only, to be redeemed before 27 August 2027, some exclusions apply); and a £30 food and beverage voucher.
• A CEWE PHOTOBOOK of the finalists’ gardens, and a £50 photo printing voucher, courtesy of the National Trust’s photo printing partner CEWE.
• Highly commended certificate.

Prizes: additional information

Prizes do not include any extras apart from those listed above.

No cash alternative will be made. Prizes are non-transferable and will be awarded to the named individual on the entry.

All prizes must be claimed by Friday 6 November 2026. If prize winners cannot be contacted by Friday 6 November 2026 to arrange delivery of their prize, they will forfeit their right to a prize.

We will not be responsible for any transport or accommodation costs incurred in the fulfilment of the prize.

We must either publish or make available information that indicates that a valid award took place. Ordinarily this will be the surname and county of major prize winners. If you object to your information being published or made available on request, or wish to reduce the amount of information to be published or made available, please email us at skygardeningchallenge@nationaltrust.org.uk. In such circumstances, we must still provide the information and winning entry to the Advertising Standards Authority if challenged.

National Trust and project partners may ask for your consent to share your name and film or photograph you, your balcony, or window box; and publish it online or in print during or after the competition. You may refuse and it will not affect your chances of winning.

Your privacy is important to us. We will process your personal data to manage your participation in the competition. For further information on how we look after your personal information please visit www.nationaltrust.org.uk/our-policies/privacy. If you would like a printed copy of the Privacy Policy you can request it by post by contacting: The Data Protection Office, National Trust, Heelis, Kemble Drive, Swindon, SN2 2NA.

"We "and "us" means The National Trust for Places of Historic Interest or Natural Beauty, registered charity number 205846, registered address Heelis, Kemble Drive, Swindon, SN2 2NA.

Events may occur that may render the competition itself or the awarding of the prizes impossible due to reasons beyond our control and accordingly we may vary or amend the promotion. We will do everything we reasonably can to ensure that winners receive prizes of at least equal value.

By entering into the competition, you are agreeing to these terms and conditions.

These terms and conditions are governed by English law, and the parties submit to the non-exclusive jurisdiction of the courts of England and Wales.