The city wall is in bloom from May / June. The gray brick walls turn yellow from the flowers of perennial wall rocket,yellow corydalis and sticky hawkweed. Such a flourishing wall is quite special, because a wall is a difficult place to grow for plants. There is little food, little water and often there are large fluctuations in temperature. Plants that are able to survive here, such as the sticky hawkweed , often originate from mountainous areas, as southern Europe. The citywalls function as some kind of artificial rocks, where these plants can grow nowadays.
Relationship with humans
Why we do what we do
Maastricht is known as a city with interesting wall flora. This extensive wall flora was able to develop here thanks to the long history of Maastricht as a fortified city with stone city walls and fortifications. A rich wall flora has emerged here over the centuries. The lime mortar that was used in the constructions is an ideal base for wall plants that originally grew on limestone rocks. They ended up here, often because they were collected for their medicinal properties. They were grown in herb gardens of monasteries. From these gardens they “escaped” and became wild in places that looked most like their original habitat.