The Isle of Mainau: a gardening paradise

Autumn Colour Isle of Mainau © Isabelle van Groeningen

Autumn Colour

At the opposite end of the country from Berlin lies Lake Constance at the point where Germany, Switzerland and Austria meet up. With a surface of 473 square kilometers, it is the third largest lake in Central Europe and crossed by the Rhine. Recent reports have revealed its water quality to be so clean, that it can no longer sustain its fishstocks.

Southern shores of Lake Constance © Isabelle van Groeningen

Southern shores of Lake Constance

At the south-eastern end of the lake, not far from the town of Constance, lies the small Island Mainau covering 45 hectares. Here lies one of Germany’s best-known garden treasures. At the northern end of the island sits the house, built in 1746, owned by the Bernadotte family. The Grand Duke Frederik 1st of Baden acquired the property in 1853, and that is where its garden history began. He developed the parkland by planting an arboretum with trees he collected on his travels. Successive generations have continued to develop the garden. Its unique climate allows them to grow many plants which in any other part of the country would need frost protection. Being a small island surrounded by a large body of deep water, the climate is exceptionally mild. During our visit today, the morning mist over the lake slowly evaporated, but even by lunch time there were still smoke-like traces hanging over the rose garden diffusing the autumn sunlight beautifully.

View down Cascade across the misty lake © Isabelle van Groeningen

View down Cascade across the misty lake

Garden features

The level of craftsmanship on show in this garden is quite unique. Everything is done by the in-house team of skilled people. Four designers are full-time employed to work out planting plans and design and build new features. The garden staff of over 80 sees to it that every morning the paths are swept, beds are maintained in perfect order, the tree collection is well maintained, the fruit tree plantations of over 7 hectares are seen to and the nursery with its collections of orchids and tender plants are doing well.

Building work is carried out by their own team, and that to the highest standards with the best materials. Walls, steps and paving show great craftsmanship and great detailing, using fine materials.

The Arboretum

Three dimensional bedding with a bird lost among the trees © Isabelle van Groeningen

Three dimensional bedding with a bird lost among the trees

The park contains many spectacular specimen trees that are beautifully maintained. A stand of Thuja plicata planted in 1864 has developed into magnificent trees with beautiful stems. Nothing to do with dull-green hedges! These and many other special conifers provide a wonderful green contrast to the glowing autumnal colours of buttery yellow Liriodendron tulipifera or the numerous reds of Liquidambar styraciflua. Everywhere hang the delicious smelling clouds of burnt caramel of the Cercidiphyllum japonicum which feel so much at home that they have selfseeded themselves throughout the garden. An impressive avenue of Giant Redwoods Metasequioa glyptostroboides takes the visitor up towards the house. They are already massive, they will become breathtaking as time goes on and they continue to gain in height.

Rose garden

A formal rose garden next to the house is as formal rose gardens tend to be in the autumn, no longer at their best. I find this is always an interesting time to see which roses are still doing well. Tired after a long summer, standard roses particularly show up their weakness now that there are no longer the flower masses to detract the eye: straggly growth emerging from a knobbley graft.  The way to avoid this is by planting climbers grafted onto stems. Here the lovely old climber ‘Alberic Barbier’ has developed into a large umbrella of foliage, so there was not a knobbley knee in sight.

One rose that really stood out for its amazing abundance is ‘Fortuna’ a low growing   floribunda rose still covered in a mass of single pink flowers, with hundreds of buds still to come.


Dahlia 'Baby Blue' © Isabelle van Groeningen

Dahlia ‘Baby Blue’

Below the parkland lies a huge flower garden. Part of it is dedicated to large shrub roses, part of it is a huge herbaceous and grasses garden, part of it are giant dahlia borders. All perfectly staked and regularly dead-headed so that even this late in the season the sheer the scale of them with a colourful backdrop of autumn colours they take your breath away. ‘Baby Blue’ is a tiny pompom dahlia with pink flowers that caught my eye due to its exceptionally small flower.

The generous use of grasses in the herbaceous garden mixed with asters, late anemones and the last of the Aconitums make this garden also worth its while.


The garden is best known for its bedding displays, and these draw the thousands of visitors on a daily basis. These are also the reason why the plant-loving garden visitor may be frightened off from visiting this garden, be it unjustified. Yes, there are brightly coloured bedding displays whose designs and themes change from year to year. There are three dimensional figures planted up with bedding scattered about. They are befitting of a 19th century garden and would have been a dominant feature in most of them, but regrettably have vanished from most gardens as nobody can afford it anymore. It is the most labour-intensive form of gardening that exists and that is precisely why, it is rather nice to indulge in this sort of garden once in a while as in combination with everything else on offer here, the visit always proves enriching especially on a sunny autumnal day.

Go and visit: the garden is open every day of the year, from sunrise to sun set.