There is a Konsum supermarket in a part of Dresden that is called Weißer Hirsch. You can easily get there by tram line 11, getting off at Plattleite. There are several bins behind the store; look for the one which has a Food Not Bombs sticker on it. You can get vegetables, dairy products, sometimes flowers and, if you're lucky, soy milk from that bin.
More centrally located you can find several supermarkets between the old town and Johannstadt and in Neustadt with open dumpsters usually containing lots of veggies/fruit. The Kaufland at the Kohlenstraße in the south of Dresden has well accessible dumpsters with a lot of vegetables and fruits.
See the map for details (feel free to edit it too!).
<googlemap version="0.9" lat="51.050675" lon="13.783722" type="map" zoom="12" scale="yes" controls="large"> 51.051489, 13.751317, Netto 51.056914, 13.76527, Aldi + Konsum several smaller bins for veggies + fruit. sometimes packaged stuff in the bigger dumpsters 51.052213, 13.76365, Netto mainly veggies and fruit in the (3) smaller bins 51.055619, 13.775966, Netto I often found lots of veggies and fruit here 51.056823, 13.772452, Diska just 1 bin, still quite likely to find something 51.049594, 13.75438, CAP a small supermarket with lots of stuff being thrown out. The bin often contains lots of packaged stuff like yogurt, cheese, coffee, ... and also vegetables in the small bin. Unfortunately the bins have been locked most of the times in the past few months. 51.072778,13.748703, Netto Access to the dumpsters is from Louisenstraße. 51.074179,13.744207, Netto Update: This dumpster is now locked. 51.080357,13.758242, Edeka 51.066337,13.748694, To access the skips of the Konsum supermarket on Alauenstraße, you have to go the drive-way of its parking lot on Katarienstraße. 51.01963,13.72346 Kaufland, the dumpsters are in the delivery area, go up the metal stairs. There is automatic motion sensor light going on at darkness. 51.03614,13.73942 Aldi, not so much stuff. 51.03290,13.75673 Netto, usually on Wednesday and Saturday a lot of stuff. 51.062906,13.821579 Konsum 51.034639, 13.734806 Netto: Usually produce, sometimes flour, flowers, yoghurt etc. There is automatic motion sensor light going on at darkness (goes off if you stand for a while at the dumpsters). (Last checked: July 2011). 51.077747, 13.718895 Netto: Good for produce. </googlemap>
Information for Dresden-Neustadt:
Rewe Bautzner Straße - dumpsters are locked away
Konsum Alaunstraße - Good spot! several dumpsters for veggies and one for milk/cheese/meat stuff, Wednesday seems to be flower day! - access via Katharinenstraße
Netto Kamenzer Straße - dumpersters are locked away
Bio Company Luisenstraße/Königsbrücker Straße - one dumpster in the backyard - they seem to recycle well, I seldomly found anything
Biosphäre Bischofsweg/Königsbrücker Straße - dumpsters are locked away
Rewe City Königsbrücker Straße - dumpsters are locked away
Edeka @ Heeresbäckererei - several dumpsters, no competition (at least I never met anybody there)
- There is a freeshop Umsonstladen in  (address: Alaunstraße Nr.68, in a Backyard called "Sonnenhof"). Open monday till friday, 5 to 7 pm. They also have a Foodsharing fridge.
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