In the page's words:

SoLaWi Köln is a solidarity-based harvest community that grows fresh, high-quality vegetables in the west of Cologne. Instead of buying each piece of vegetable individually, we collectively finance the vegetable cultivation for an entire crop year and receive the entire harvest in return. The budget required for this must be obtained in advance at a bidding event. Solidarity is also the overriding principle here: lower-income participants are supported by those with more financial means, making it easier for an entire community to access high-quality food.