Currently, the main portions of the modular green roof consist of two separate gardens: the succulent/xeric garden, and the prairie garden. At the start of the semester, we began to weed the succulent/xeric portions of the modular green roof. While the plants provide an attractive and native take on a traditional roof garden, (as with most plants) it takes a little while for them to establish. Meanwhile, irrigation provided to establish/maintain the garden as well as the low density of the plantings inevitably invited the weeds.
In addition to crab grass, we pulled a total of 453 weeds. Pictured below are some of the species we removed from the modules:
In addition, there was much cilantro from a previous planting that found its way into several of the modules (81 plants in total).
While this is a normal thing to expect for the low density plantings, adding density and lighter irrigation will minimize the weeds in the long term.
On the same day, we seeded several types of succulents and sedums, but many if them did not seem to establish (at least not yet). This being said, we learned that transplanting pre-potted plants or planting plugs is a more reliable way to ensure that new plants flourish. Since then, we have added many more plants to the modules, adding both to the density and appeal of the xeric/succulent garden.