Creating a Standard Bay Tree
Topiarized evergreen herbs can be very expensive to buy, but large specimens do take many years of careful pruning. The techniques involved are simple, however, so try this at home and enjoy spectacular results.
From: DK Books - Herbs
Young, single-stemmed specimens are easiest to work with, which can often be bought as pots of young seedlings. Using a healthy, vigorous plant, pinch or cut off enough leaves to create a clear stem of the desired height.
To promote bushiness, pinch out all the side shoots to within a few nodes of the main stem. As the branches regrow and fork out, more pinching out will be needed. Remember to save the bay leaf prunings for the kitchen.
Pinch out the main growing tip to "stop" the plant from growing much taller for the next year or so. It also helps the other branches fill out. Only pinch out the tip if you are sure that the tree has reached your ideal height.
Topiarized bay trees can become quite top heavy and will need extra support. Insert a garden stake into the rootball and loosely tie the stem, in two or three places, to the stake using garden string or expandable ties.