What are we going to do?

Our sustainable house of biodiversity.

In 2023 our thoroughly renovated Three Climate Greenhouse is an oasis where you see, feel and smell the beauty of biodiversity. Where education and wonder will blend organically. Where you will understand we won’t survive without an abundance of species and vital ecosystems.

Thousands of plants on the move

Thousands of plants will have to be carefully relocated. Our tropical collection will move to our current subtropical department. Subtropical plants move to the south side of the greenhouse, where our beautiful collection of indigenous Cape flora will find an ideal environment.

See, feel and smell biodiversity in three climate zones.

Tropical climate

Going for the top!

Welcome in the tropical rainforest. Teeming with life, harbouring countless species. These forests are a biodiversity goldmine where thousands of plant species have found their niche. There is always plenty of water, plenty of warmth. But make no mistake: competition is ruthless. Every shrub, plant and tree tries to make its way toward the light. Some plants and trees stay low, extending their leafs and branches sideward, creating extra chlorophyll to catch as much of the dim light as possible. Other plants, like the epiphytes, wind and twist themselves around gigantic trees, to end up in their crowns to absorb the light.

Desert climate

Necessity is the mother of invention

The deserts seem to be a hostile place to live in. Especially for plant life that is dependent on water and air. But even here, life survives. On every continent, plants have find ways to survive ultra-dry places. Cacti and succulents appear to be family, they look alike, but closer inspection reveals they are not. Despite being oceans apart, different plant species have adapted and developed in similar ways to survive dry conditions, becoming almost lookalikes. It’s called ‘convergent evolution’, a phenomenon you can observe closely in our desert greenhouse.

Cape climate

Starting afresh after the fire

The South-African Cape is a dynamic environment of strong contrasts. Summers are too dry for abundant plant growth, winters bring plenty of water to make plants blossom. During the dry summer the shrubbery easily catches fire. Every seven or eight years fires will spread over hundreds of miles, propelled by the strong winds. It’s all part of a natural life cycle. Once the fires die, everything starts afresh. First the bulbous plants appear, then the yearlings, followed by shrubs and bushes. New plants on the block have just as much chance to seize their place in the Cape’s ecosystem as the regular plants have. Small evolutionary changes may persist, while extinction rates are low, because the climate has been very stable over the past centuries. The Cape is true biodiversity hotspot, a botanical pearl.

Biodiversity is vulnerable

Climate has an effect on plants: hence a cactus looks a lot different than a tropical palm. The three climate zones in the new greenhouse are very different form each other, and by experiencing them close after one another, by being able to compare them in a direct and shorter time span, it becomes easily clear that every climate has its unique characteristics that determine the development of plant life. Obviously, this also shows that (rapid) climate change can have a tremendous impact on plants, plant species and plant biodiversity.

A greenhouse for the future

Sustainability ranks high on our agenda and is an indispensable part of our mission. We took a major step in sustainable energy use when in 2017, we connect our heating system to the Hermitage Amsterdam. Yes, their art warms our plants! The museums air-conditioning has to maintain a constant, cool and dry temperature. The redundant warmth is transported to the Hortus to heat our greenhouses. The resulting cold is transported back to the Hermitage. Over 2017 and 2018 we have cut back our CO2-emission with almost 480 tons.

We want to take our sustainability goals some steps further. In 2023 the thoroughly renovated Three Climate Greenhouse is a sustainable home of biodiversity. The current glass windows will have been substituted by insulating, double glass. The roof will be covered with a transparent, insulating ETFE foil.

On the interior, the collection will be organised in a way to optimise care en maintenance. Hi-tech climate regulation, heated soil and circular water use will create ideal, sustainable growing conditions. Day in , day out, in every season.

Facts & figures

Architect: Zwarts & Jansma Architects
Contractor/builder: to be considered
Installations: to be considered
Project coordinator: Krijn Braber – Infinitus Energy Solutions
Building coordinator/controller: Remco Spigt – C&R Hospitality Services
Greenhouse lay-out: Landlab landscape architects
Fund raising campaign: LAVA

Cost estimation: 4,6 million euro (additional costs included)
Time period: 2019-2023
Climates: 3
Plant species: 2.500
Start renovation: January 2022
Finished: May-June 2023
Reopening: June-July 2023

Press & info

For more information, images or an interview with director Carlien Blok or one of teh other members of the projectgroep, please contact Barbara van Amelsfort, marketing and communication
via 020-7025409 / 06-41818562 / barbara@dehortus.nl