We have mixed with Japanese and Mediterranean style with very good results. The gravel is not lost at all with the wind and the contours we use a special curb to such use. Usually gives more gravel problems cats and dogs than wind. Its really easy to stay gravel on site. The picture above its a mix style

The view through the circular wall is really inviting. The irrigation system looks a very ingenious idea too

Thanks C J Gardens. The updated photos have been added to the project. They are taken 4 months after planting. There are still some gaps, as the client wished to let the garden grow and add plants herself; a process that is ongoing. Link to project below: https://www.houzz.co.uk/projects/2444892

Hi Redkez It is an old Arts and Crafts design idea - formality close to the house, gradually evolving into informality the further away from the house you go. But I also love mixing formal plants with softer more naturalistic ones. As regards the plants, in relation to perennials there is no real benefit in buying bigger than 2L as perennials should grow quickly generally if they are happy. Alchemilla is usually a fast grower, so it may be the conditions aren't right for it? The other thing is to pay close attention to looking after your soil. I always specify putting a lot of organic matter into the gardens I design - perhaps your beds would benefit from a good dose? Ideally it is nice to top dress the beds every autumn with 30-50mm of organic matter like compost or well rotted farmyard manure. This garden also has irrigation which I have found does really help the plants get off to a great start.