Easily increased by dividing the bulbs in July or August, and replanting them from 4 to 6 inches apart.
As old plants do not bloom so long as young ones, occasional replanting is desirable.
This has led to restrictive measures, the vines being tapped under definite regulations as to the manner and time of tapping, and also to requirements as to replanting vines to take the place of those which have been injured or destroyed, certain areas being periodically closed.
A considerable part of the province is forested and the state requires systematic replanting.
In the grand duchy the forest has almost entirely disappeared, but owing to the compulsory law of replanting in Belgium this fate does not seem likely to attend the Belgian Ardennes.