Tag Archives: rooftop gardens

Rooftop raised beds for bees

April 2023

This area of roof 12 storeys above the City was originally earmarked for honeybee hives, but we explained to the client (a large real estate managing agent) that hives don’t do well in the City due to many factors including lack of forage, We suggested they transform the area (25m2) into a bee garden for wild solitary bees and bumblebees to boost biodiversity. They agreed. So we made wooden raised beds earlier this year to hold 300mm of soil/lecca, fitted a drip irrigation system in case of drought and on 5 April 2023 myself and Alex finally got up on the roof to plant a variety of tough, bee-friendly shrubs and perennials that will sequentially bloom from later this month through to autumn. We decided that the first planter would contain plants that flower late spring, the second planter by mid summer, and the third for late summer plants.

I hope the depth of soil, the bark chipping we used as mulch and the irrigation system will prevent the roots drying out and give the plants plenty of room to grow and spread.

Plants include:

  • Rosemary (Rosmarinus officinalis ‘Prostatus Group’ and Rosmarinus officinalis ‘Miss Jessopp’s Upright’)
  • Perennial Wallflowers (Erysimus ‘Red Jepp‘)
  • Hebes (pinguifolia ‘Sutherlandii’ and pinguifolia ‘Pagei‘)
  • Lavender (Lavandula intermedia x ‘Edelweiss’)
  • Vipers bugloss (Echium vulgare)
  • Perennial cornflower (Centaurea nigra)
  • Lamb’s ear (Stachys byzantina)
  • Korean mint (Agastache rugoso)
  • False dittany (Ballota pseudodictamnus or pseudodictamnus mediterraneus)
  • Sedum Autumn Joy (Hylotelephium ”Herbstfreude’)

We’ve also scattered seed balls over one of the fourth planters to create a wildflower raised bed. I’ve never tried this before, but because it’s a rooftop that is not used by staff or clients, I think we can get away with experimenting a bit, rather than having to focus on aesthetics. If the seeds don’t take, we can always plant more shrubs. Maybe an Strawberry tree (Arbutus unedo) for winter forage.

As well as bee-friendly forage throughout the spring and summer, we are putting in 2 x bee hotels for cavity nesting solitary bees. It will be interesting to see if we get any nesting so high up.

I will be visiting each month to maintain the planters and monitor the visiting bees so watch this space.

Summer 2023

Late summer planter full of Korean mint (Agastache rugoso) and wild flower planter with red poppies

Bees seen in the first year:

  1. Honeybees (lots from a neighbouring rooftop hive)
  2. Red mason bees on the wallflowers – we introduced some cocoons which hatched and the bees were foraging on April/May blooms. (pictured left)
  3. Common carder bees foraging on Echium vulgare in mid summer and Ballota (pictured right) in late summer.

A year on…..end of Feb 2024

The spring planter is blooming in late February with Wallflowers and Rosemary. It is looking a bit crowed. I think I put too many wallflower plants in! The mid summer planter is looking neat and tidy and ready to bloom in May/June.

The late summer planter has a few gaps as a couple of things didn’t do well. I may add a second Ballota as it is thriving. The wildflower meadow looks interesting. The Rosemary plant in the middle will provide early forage as wildflowers themselves don’t feed bees until mid summer.

The Centaurea nigra looks as if it is about to bloom (end of Feb!) and the electric blue Muscari armeniacum (Grape hyacinth) bulbs I planted in the autumn are about to appear. And the bee hotels, which I didn’t remove have a number of plugged tubes so it will be interesting to see when the adult males start to emerge.

We’ve had such a wet winter that I’ve not yet turned the watering system back on. I will keep an eye on the rainfall over the next few weeks to judge when it needs to.

Interview with William Ball, Portfolio General Manager, BNP Paribas Real Estate on making Belgrave House bee-friendly

When William Ball, Portfolio General Manager at BNP Paribas Real Estate, was first approached by his client Grosvenor Group about installing a roof garden on its Belgrave House property in Victoria, six years ago he was concerned over the practicality of managing such a project with limited knowledge.

“The roof isn’t accessible and I thought the tenants would not be able to see the benefits to the property of investing in it,” he explains.

Benefits outweigh costs

Fast forward to today and William says the tenants and Grosvenor now fully support the biodiversity project on the Buckingham Palace Road office block.

 “The benefits outweigh the costs one hundred fold. And it’s the right thing to do for the environment. The roof garden and the bees are one element of promoting environmental best practice. It’s one of the reasons Belgrave House has retained its BREEAM excellence rating and its ISO14001 year after year.”

William has more than 35 years’ experience in the property and facilities management industry. In 2018, he was awarded the national BNP Paribas CSR Award and in 2019, his team won the Professional Facilities Management Award for CSR.

Introducing bee hives

The same year, he contacted Urban Bees Ltd to install and maintain bee hives on Belgrave House. Grosvenor, whose own staff Urban Bees had trained as beekeepers a few years earlier, paid the initial start-up costs.

He proudly hands me a jar of 2021 Belgrave House honey with a pretty label designed by the receptionists. The bees are a great way to bring together his 21-strong team of security staff, cleaners, receptionists and engineers, he says.

“We all take great pride in the bees”.

William believes the bees have contributed to a string of environmental awards, including five Green Apples, three of them gold. They adorn his basement office, along with trophies and photos of him and his team collecting them.

Honeybees will easily fly a mile or two in search of an abundant food source. And William, who is the property site representative for the hives, has tracked the Belgrave House bees to the Queen’s gardens at the end of the road. But he wanted to create a bee-friendly garden on the roof for wild bumblebees and solitary bees.

Steps to creating a bee-friendly garden

William called on the expertise and goodwill of colleagues to help achieve his vision. The building consultancy surveyor advised that the roof was strong enough to hold a few planters filled with wet soil and flowers and shrubs, his engineers agreed to make planters out of wooden planks that William sourced, and the Grosvenor gardeners ordered extra lavender and other bee-friendly plants recommended by Urban Bees from its Plants for Bees list.

There are now four planters, one full of lavender and others planted with a mixture of perennial summer-flowering alliums, foxgloves and harebells (pictured above), as well as early-flowering hellebores and late-flowering echinacea.

Observation nesting box for solitary bees

Wind can be a problem for bees eight storeys up. “You could see the honeybees were really struggling getting to and from the hives,” recalls William. So, his engineers put up trellis against which 2ft high Ceanothus ‘Skylark’ bushes (pictured below) act as a windbreak. And their electric blue flowers are buzzing with all types of bees in late spring. Urban Bees added an observation bee box (pictured below right) for solitary bees to nest in.

Bee visitors

William spends many a summer lunch hour inspecting the small, 12 square metre, bee oasis, breathing in the flowers’ perfume and spotting different bees. He’s photographed many wild bee visitors including bumblebees with white tails (below left) and red tails (below middle), as well as some honeybees (below right).


Each June on World Ocean’s Day, his team has a stand in the reception of Belgrave House to raise awareness about environmental issues. They work with a school in the Philippines to tackle the huge problem of plastic ocean pollution.

“We have honey and leaflets about our rooftop bees on the stand as the bees can really engage people in the bigger picture.”

Staff who want to know more are given a copy of The Good Bee, by Urban Bees founders, Alison Benjamin and Brian McCallum, showcasing the world’s 20,000 solitary and social bees and how we can help them. 

“’We never knew there were so many bees’, is most people’s response.”

A webcam of the Belgrave House bee hives keeps staff up to date on the honeybees. In 2022, William plans to have a screen in reception live streaming the three hives. And he hopes to introduce a small water feature on the roof for bees to drink from and other wildlife to visit.

William’s advice to other facilities managers

For parts of London not able to sustain honeybee hives because there isn’t a plentiful supply of forage. (Afterall, not everyone has Buckingham Palace gardens on their doorstep), William’s advice for facilities managers is to look at their ESG strategy.

“Do a biodiversity plan for your property. Look at the bigger picture. Make sure you have a well thought our process and escalate it. Start small and grow as the tenants come on board. The cost is a miniscule part of their service charge. Start with plants and see what bees come without installing honeybees. Work with people like Urban Bees, who know which are the best bee plants in these windy, exposed conditions to ensure there’s food year-round for all different kinds of bees. Food is essential, along with creating places for wild bees to nest.”

“You do have greater output [jars of honey] with honeybees so there can be greater interest and support from tenants. But honeybees aren’t integral to having a roof garden on an office.”

All photos taken by William Ball.
  • For more information about how Urban Bees can work with your company, contact Alison Benjamin at Urban Bees alison@urbanbees.co.uk 0788 4054150