My thoughts were similar to others': Cardoon and artichoke (Johnny's, my favorite seed catalogue since they have unsual and short season varieties, carries an artichoke that will produce first year if started early enough indoors) beans - dry (I especially like black and aduke) or green soy for Edamame Potatoes, though you don't want it too fertile Indeterminate tomatoes, which IME even when tied up or in large cages manage to take up quite a bit or real estate Or, make this your perennial crop bed with asparagus and rhubarb or small fruits like blueberries (if your soil is acid), strawberries, gooseberries, with your fall planted crops along the edges (spinach for early harvest and garlic.) If you (and your digestive system) like Jerusalem artichokes, you could grow them here if you have some type of barrier to keep them from spreading beyond where you want, and similarly horseradish is a large plant, but needs to be planted where it can't overtake the bed from small roots left behind when harvested and replanted. Many of these perennial crops are quite decorative as well - the foliage of the horseradish and rhubarb are bold, the asparagus ferny, and the fruit plants have flowers. Some blueberry bushes have red-gold winter stems.

Taraxacums are notorious cross breeders and there are several sections each with micro species. They are very difficult to id, especially with no foliage or habit to see. If the stem was soft and hollow with milky sap which stains fingers brown it probably is a dandelion of some sort. Well nigh impossible to pin down further. I have been unable to establish whether T albidum occurs in Germany. It is a Japanese native. I think you will get more responses to your queries if you post each as a new question. People may look at this thread, think they have already checked it out, and not realise there is a new question at the end.

Nope, I'll have to check it out. Don't think I ever even noticed that forum. Of course, people from the tropics may be less impressed. When I go to Hawaii, I find people there are more interested in temperate area plants. Just like many of us, they get bored with what's in their "backyard".

Thanks all for your thoughts. Don't want to tie anything to railing as I often have to move the pots to get around on my very tiny (NYC) balcony. As for 'pea gravel' and 'Turface', don't even know what those are but suspect it's not something a person with no car and lives in NYC could easily get, never mind have storage space for. My plants tipping over is really a nuisance more than anything. Never got any severe damage more than a broken branch or two. Maybe I'll just have to accept that sometimes it will happen. ;-)