Firstly, Be Patient!
Most people imagine the ideal tree shape to be like a mushroom or umbrella but don’t be in too much of a hurry for your single stem frangipani to produce branches. The future stability of a frangipani depends on it developing a strong straight trunk.
The Natural Shape of Frangipanis
When frangipanis grow from seed in nature, frangipanis start by developing a long straight stem. If they have sufficient nutrients, they can easily grow more than a metre tall before producing its first fork.
From there, it will produce more and more branches and turn into an umbrella or mushroom shaped tree. After the tree has increased in size and has many branches, the lower branches will not be near the ground and not need pruning thanks to developing a good trunk to start with.
Prune As Less Often As Possible
Sometimes you can improve the shape of a small frangipani tree by cutting off a single branch or improve the shape of a large frangipani tree by “cropping” it. However, after cutting off a frangipani branch, there is a scar which will be visible for quite a long time, usually several years, so pruning willy-nilly is likely to make your frangipani more unattractive than attractive.
Shrub And Bonsai Shaped Frangipanis
If you want a short frangipani with numerous branches, is best to start with the desired shape rather than change a its shape. Dwarf varieties naturally grow sideways more than upwards and many other frangipanis are grown from multi-stemmed cuttings.
Putting a shrub like frangipani into your garden can fill a gap, can match the surrounding plants and have a balanced appearance immediately. If the shrub like frangipani grows year after year and produces too many congested branches or side branches which are too low, branches can be pruned off and thinned out in the future.
Bent Frangipani Branches
If you have a newish and smallish frangipani tree which has branches bending towards one side or a single branch bending in a wrong direction, it’s possible to train (control branch direction) those branches using string or light rope.
The lower and thicker the branch, the more difficult it will be. You will need to be more gentle, allow more time and possibly need to pull the trunk or other branches in the opposite direction so they hold their position.