Lückengrün
Planting of joints on sealed surfaces in public space
Vegetated paving joints not only cool cities, but also let desolate streets and squares blossom. The project Lückengrün proposes the redesign of the sealed market square in Halle with exceptional joint planting. The plants are carefully selected and matched based on their flowering time, flower colour, natural habitats and their significance for insects. In addition, the existing joints are extended and expanded using standard road construction machinery to not only create more space for greenery but also give the market square a lively pattern. The geometric mesh of dots and lines becomes denser in some parts and diffuses into the large areas of the market square at the edges.
| student: | Hannah Tuchel |
| project: | The Plant Project – Resilience Part II |
| year: | 2024 |
Plants have enormous flexibility and can adapt to many manipulations. At first glance, they don’t convey obvious signals about the limits of their vulnerability. Perhaps we should value the plants that manage to live in the tiny gaps of urban spaces by their own strength, rather than viewing them as dangerous, unruly “weeds” and trying to eradicate them by all means. These small plants hold untapped potential. They can not only bloom beautifully but also form symbiotic relationships with insects, help cool the urban environment, and stabilize the gaps between paving stones with their small root systems, keeping the stones in place. At least, this is true for some of the plants that live in these spaces. Not all are harmless. A frustrated official responsible for street and pathway safety emphasizes the dangers associated with gap greenery, which can damage pathways and streets and pose a tripping hazard for the blind, wheelchair users, the elderly, and children. Affected people do not necessarily agree with this. Naturally, the planting should not pose any restrictions for people with mobility impairments, and therefore should be implemented only in specific spots on squares and along the edges of pathways. The idea of greening gaps aims to control plant growth, not only eliminate it. The effort to maintain walkways must be undertaken anyway and could be redesigned to allow these spaces to be inhabited by plants.
The intervention suggests using existing road construction machinery: 1 Machines like a concrete or asphalt milling machine, whose milling width can be adjusted to fit the respective gap paving, serving as a superficial extension for the gaps.
2 A core drilling machine, which can drill holes in the gap intersections to give larger plants more space to grow.
3 A diamond chamfer drill, which can also be used to widen the gaps and create conical holes at the intersections.
The expanded gap structure should then be planted with selected plants that reflect locally occurring species, are heat-resistant, and can serve as a food source for insects. These insects include not only bee species but also butterflies, beetles, and caterpillars. With the selection of plants and their different blooming periods, various combinations of year-round and perennial blooms can be created, which can be planted in the gaps as perennials, bulbs, or seeds.
