Training Japanese Garden Shrubs
I'm often asked how to create the compact shrubs found in Japanese gardens such as the palmatum just coming into leaf below. The secret is to use the same techniques as used in bonsai. For example, with maples, as soon as the leaf buds start to burst in the spring, watch for the first pair of leaves to form. Shortly after this, a shoot will start to grow - VERY quickly - from the junction of the two leaves. As soon as you can pinch this off leaving just the pair of leaves. This needs to be done every year with no exception! This will prevent the shoots growing too long and a pair of buds will develop in the following year. If any shoots grow later in the year that stray outside of the wanted shape cut them off. If the tree is very strong, all the leaves can be cut off and a new set of smaller leaves will grow and maybe a a few new buds will develop back on old wood. Further info at: http://www.bonsaiprimer.com/pruning/leaftrim/leaftrim.html
The above done in combination with pulling branches down with rope to hold them for one season in a more horizontal position to force horizontal growth will produce an excellent shape within a couple of years.
Japanese Palmatum Maple after 15 years in training
Another maple showing some training ropes after 15 years in training
Pines (Pinus Parviflora or "white pine")
The four foot white pine also needs to be trained otherwise it will run away itself. To prevent this it should not be planted in the ground otherwise a tap root will form and it will well nigh be impossible to keep a tight habit.
There are many different ways to train white pines which consists of a variety of activities:
New buds forming on a white pine.
In the spring the tree will develop 'candles' and if foliage 'pads' or 'clouds' are wanted, then the candles need to pinched back in a careful manner. Here's how I would do it.
Further advice on training a white pine can be found at: http://www.bonsai-tree-store.com/white_pine.html or http://www.bonsaiprimer.com/pruning/pines/pineprun.html