Castlefield Viaduct ‘sky park’ gears up for July opening

More than 3,000 plants will soon cover the grade two-listed bridge, which the National Trust says will open for guided tours at the end of July.

Originally, the park was to open on 3 July, but the Trust said it had experienced unexpected delays in the £1.8m project.

When it does open, Castlefield Viaduct will be a temporary park – operational for only 12 months. It will spend that time acting as a living, breathing consultation, as the Trust seeks to gather feedback on how residents and visitors want to see the space used.

The transformation of Castlefield Viaduct in Manchester is well underway. pic.twitter.com/lQBCGqPOIJ

— Julia Hatmaker (@JuliaHatmaker) June 16, 2022

Guests will work their way along the 330-metre viaduct, experiencing several unique garden areas and learning about the viaduct’s history.

The entrance will be an experimental garden, in which 280 sandbags will become planters holding ferns, broom, buddleja, liriope and more. This is the favourite section of Pamela Smith, senior national consultant for gardens and parklands at the Trust.

She described this entry garden as an “aperitif of horticulture” that sets the tone to help visitors as they proceed through the park and eventually “get to the wow”. The “wow” in this case will be a show garden at the end of the guided tour route.

Many of the show garden plants have yet to arrive on the viaduct site. These plants are being grown at Dunham Massey, a plant nursery in Yorkshire and at the Trust’s plant conservation centre in Devon.

“This is the crown”, Smith said, gesturing around the viaduct. “We have all the jewels still to come.”

• Here’s what the viaduct looked like in March as construction began

Weight restrictions on the viaduct have presented a challenge to the horticulturalists with the National Trust. They are experimenting by using a new extra lightweight and peat-free compost. Large planters may also not be what they seem – some will have polystyrene filling up the lower halves to help lighten the weight of the planting.

With no water systems on the bridge, water has to be brought to the site in tanks. Volunteers and gardeners then pour the water into watering cans to hydrate the plants. Because the plants are exposed to more wind, being so high up, they have a tendency to dry quicker. This means the Trust is using 1,000 litres of water a day to keep the plants healthy.

These restrictions have led to experimentation, and the Trust said that it will continue to have its garden team try out new planting techniques to see what works best on the site.

MC Construction is the main contractor for the project, bringing to life the vision crafted by Twelve Architects & Masterplanners.

“It’s such a joy to see this iconic structure being given a new life as well as adding to the diverse urban fabric of Manchester,” said project architect Irina Adam of Twelve Architects.

“This pilot phase of the project is designed to show visitors the viaduct in its existing state while also taking them through a series of different spaces that show how it could be transformed,” she continued.

“We’re excited to hear people’s ideas for how a larger viaduct public park could be, and to work with the National Trust on future phases.”

Ultimately, the full transformation of the 125-year-old abandoned bridge is set to cost £20m.