Cordelia de Castellane's French garden is an abundant haven of beautiful flowers

Cordelia de Castellane lives a life full of flowers. As the creative director of Dior Maison and Baby Dior, she designs collections of exquisite homeware and childrenswear often inspired by flowers – and by her muse, Christian Dior. At her weekend house in L’Oise, north of Paris, she grows hundreds of flowers for cutting. She has decorated the interior with beautiful floral wallpapers and fabrics and, in many rooms, botanical prints line the walls. ‘I’m obsessed with flowers,’ she says. ‘I grew up between Paris and the mountains in Switzerland. I used to garden with my grandmother and I always longed for my own garden.’

Owners of a flat in Paris, Cordelia and her husband used to rent a weekend cottage in the grounds of what is now their house in L’Oise. Once owned by the textile designer Primrose Bordier, the manor house stands in its own formal two-acre garden and, as the previous owners spent much time abroad, Cordelia would tend the garden at weekends while they were away. When the house came up for sale five years ago, she jumped at the chance to buy it and, suddenly, the garden was hers. ‘I immediately made the borders larger, planted a kitchen garden and started learning from podcasts and Instagram,’ she says. One of her Instagram heroes was London-based garden designer Milan Hajsinek. ‘We used to exchange messages and ideas. One day, he said he was going to be nearby, so he came for lunch. Then my small project somehow got bigger.’

Milan has helped to remodel the garden, keeping some of the original layout but adding new structural elements, including a curving cloud of clipped box between a wonderful old copper beech and a Magnolia grandiflora. The garden at the front of the house is unadorned. Elegant and simple, it has a square of lawn embellished with large box spheres. The house itself is softened by climbing roses, and by the entranceway stands a classic French pigeonnier (dovecote), which Cordelia uses for drying flowers and storing seeds.

At the rear of the house, the garden is bisected by a long grassy walk with generous borders on either side. A cross-axis path creates a view across the garden over the box clouds to the fields beyond – and back towards the greenhouse. Old-fashioned David Austin roses in pinks, creams and apricots are punctuated by cones and mounds of clipped box and skirted by vibrant herbaceous perennials. ‘I wanted a very English look,’ says Cordelia. ‘My French-style garden is at the front, but my heart was set on an English flower garden at the back.’

The lines of the outside space are designed to work with the house. ‘I wanted to link the garden and the interior,’ she says. ‘They needed a common language. I was always looking inwards and now I’m looking out.’ A greenhouse was essential and, rather than hiding it away, Milan wanted it to be a strong feature. ‘I like to put a greenhouse in the middle of a garden – I view it as a church,’ he explains. Painted a pale blue-green (the colour of Cordelia’s former childrenswear brand CdeC), the greenhouse draws the eye from every corner of the garden. A quadrangle of beds overflow with a sumptuous mix of peonies, lupins, foxgloves, phlox, larkspur, valerian and other cottage-garden favourites, which mingle in a charming, unpremeditated way. ‘I favour a natural look. It’s the same inside the house,’ says Cordelia. ‘I don’t want things to look brand new. I like to respect the DNA of a place, whether it’s the house or the garden.’ To ensure she has a never-ending supply to arrange, Cordelia has made more beds for cut flowers behind the greenhouse and recently cleared an entire meadow so she can now grow her beloved tulips and dahlias, as well as cosmos, delphiniums and peonies.

This passion overflows into Cordelia’s creative work at Dior, where she has spent hours in the archives to learn more about ‘Mr Dior’, as she calls the company’s founder. He was deeply influenced by his childhood home and garden at Villa Les Rhumbs, near Granville in Normandy. He shared his mother’s love of flowers, and every aspect of his work was inspired by them.