This shrub flowers from July through to August and forms itself into a bushy clump in about 2 years or into a tree in about 3 to 4 years. Depending on its shape it can reach heights of between 3m and 8m.
Lagerstroemia or Summer Lilac in bush form
In the first year, following planting cut each branch back to just above two buds this will encourage new shoots. The bud on the upper side of the branch should be outward facing to encourage the shape to open out and to avoid branches growing inwards. In the second year carry out the same style of pruning. If necessary cut out any branches that are sickly or dead.
In the following years (in March) cut back the prior year's branches to about a dozen centimetres in length, always making sure to cut above an outward facing bud. Make sure that the centre of the plant is well ventilated by cutting out any weak branches, which prevent light getting into the shrub.
Lagerstroemia or Summer Lilac tree
In the first year after planting, in March, stake the main central stem upright and cut off the other branches (or cut them very short). As the plant grows new shoots and leaves cut back any horizontal branches to about 10cm in length. These small branches will help the trunk to form but once this is achieved, cut them off.
In March of the second year, you can:
- Either repeat the pruning that was carried out in the first year so that the trunk gets to a height of about 1m40 or more.
- Or begin to form the boughs of the future tree by cutting the end of the central stem to leave three buds at the desired height.
In March of the third year, cut back the three branches (new boughs) to above the second or third bud.
In March of the fourth year cut back each branch just above the second bud. Get rid of any lateral branches (if this has not already been done).
In the spring of the following years (in March) cut back all the branches of the prior year to a short length, about 12cm above their base and always above an outward facing bud. Allow air and light to get to the centre of the tree by cutting out any dead or weak branches.