They must cope with very difficult growing conditions. There is often not much room for roots to develop, and the soil is compact. There may be too much or not enough water available. Above the air is polluted. Some cities have to spread salt in winter. Following the climatic changes there may arise problems with extremes: Prolonged periods of inundations or drought.
Elms are good adapted to such challenges, especially varieties originating from Wisconsin as most of the resista® elms: In Wisconsin winter temperatures can go below -35°C whereas in summer they can exceed +40°C.
Another advantage of elms is their ability to regrow several times in one season and recover from damages by a late frost, an insect attack, traffic damage or strong pruning. They forgive severe pruning if necessary to put in new cables underground or change the profile of the tree above.
Many cities have seen the potential our elms, and we are confident to see many more in the years to come.