Sheltered site/not - this depends on the topography/local wind conditions and the degree of shelter provided in your garden.
Considerations - staking is advisable with small numbers of plants to safeguard from the unpredictable uk weather/may june gales. Larger borders – a matter of choice/manpower
Support - use a tough but slight stake that does not detract from the beauty of the plant; secure the plant with a soft bendable galvanised split ring, not the hard ‘springy’ kind.