How can you ensure that cut flowers from a flower shop or the garden will last as long as possible?  

By Not Cutting Them With A Scissors.
Always Use A Very Sharp Knife.

Most people simply put flowers in water and hope for the best,with out realizing they have some control over vase life.  

Because cut flowers age faster than those on the plants, it is important to understand the conditions that affect the length of their life. Water and temperature play important roles. If flowers wilt and cannot takeup water, they die. Reducing the temperature in which they are kept will slow their aging. Lowlight intensity, low relative humidity and fast air movement will shorten their life. 

One approach to extending their life is to try to create conditions similar to those which existed before the flowers were cut. Put them in water containing flower food. A number of flower foods are available commercially. Their effectiveness appears to be influenced by local conditions. Since no one flower food has gained universal acceptance, it isbest to contact a flower shop for a suitable product.  

Flower food should contain sugar, something to kill bacteria and an acidifier to help prevent blocking of stems by material produced by the flowers.  

The following steps can increase the life of your cut flowers:use a sharp knife or pinch type pruner to trim one to two centimetres from the bottom of the stems. It is better if this procedure is done under water, especially important when cutting roses. This will help them take up water by exposing a fresh surface. The cut can be straight across or on a slant:  

• Remove foliage that would be below the water level to eliminate a possible source of decay. 
• Use warm water (45 degrees C) in a clean container. Warm water will move into the stems faster than cold. 
• Put flower food in the water. 
• Place the flowers in the warm water. 
• Place the flowers in a location that is bright, but out ofdirect sunlight and away from heat sources and drafts. 
• When the flowers are not on display, their life can be lengthened by putting them where the temperature is lower than room temperature. Locations as cool as 36 degrees F.  can be used. A refrigerator or cold room will be fine as long as unsealed fruits and vegetables are not present. They produce ethylene,which will shorten the life of the flowers. 
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  If the flowers start to wilt, these steps can be repeated.