Just how long should they last?

I have been reading through Paula Pryke's new book "Flower School" which is very interesting - her style with its tall glass vases full of vegetables topped by tight domed bunches of flowers is now widely copied and very popular - it is useful to know how the mechanics work in case I ever need to emulate them.
One of the things that she discusses is how long a vase life customers should expect from a bouquet - she fixes on 5 days. This is one of the things that I often discuss with people - there seems to be a feeling that garden flowers will not have much of a vase life. I think that this may be partly the publicity from the Flower and Plants Association, the trade association for the cut flower industry, which promotes florist flowers and metallic solutions for conditioning. It is probably also due to people's experience of picking flowers while walking round the garden, probably in the heat of the day, and then putting them into a vase only for them to wilt soon after.
People who have bought garden flowers from me often go on about how the vase life is superior to flowers bought in a florists - I think that it is largely to do with how you treat them.

Tips for picking and keeping garden flowers

• Either pick first thing in the morning or last thing at night when the flowers are cool.
• Pick straight into a bucket of water - tepid water is ideal - if stems are hollow it is worth recutting the stems underwater to release air bubbles.
• Do not overstuff the bucket or heat will build up.
• Put the flowers somewhere cool and preferably dark for at least 2 hours.
• Recut the stems at an acute angle to give the largest area for stems to take up water.
• Make sure vases are really clean, use flower food, arrange flowers.
• Put flowers somewhere cool, out of direct sunlight and away from fruit bowls.
• If you really want to keep the flowers change the water every couple of days and remove any flowers that begin to wilt before they effect the rest.

The photo is of blue cornflowers - one of the few flowers that I would not expect to last a week - but then they are so beautiful (for 6 days or so) who can resist?