Well, cucumbers and squash, of course, but how are you going to pick the fruit? The vines are too prickly and too breakable to pull them up every couple of days for picking. Can you reach them from below? If so, that's probably the obvious bet. I suppose you could try pole beans, but I think they will drop down and then curl back up, which might not be too bad, as long as your wall is pretty high. You might try bush type crowder peas or lima beans. They all cascade some. And then, if you want to be adventurous, you could try currant tomatoes. Those plants sprawl and cascade. The red fruit is really pretty. But again, all of these require your being able to get to the fruit or you'll have a rotting mess.

Yes, donnabaskets, I can pick from the wall from the ground. My backyard is terraced and I just built a raised bed on top of the first terrace, which I walk "into" about 10 feet from my back door. Vegetation would "cascade" down, right into my hands :-)

My goal is to also break up the expanse of the wall, which is made of cinder blocks. I'm thinking I would have 3 or 4 such cascading vegetables or flowers. We're talking 30 feet of wall.

I will look into currant tomatoes--- never heard of them.

Thanks for your input. Anyone else have good vegetable ideas?

Japanese yard long beans. They kinda taste like asparagus and grow quickly with a pretty purple flower. We put our cukes on a 3 foot chicken wire fence so we can find them. We should probably use a five foot fence. They hid so easily. You can do squashes , but you might have to support the squashes once they grow so they don't break off of the vine. I read somewhere that you can support them with old pantyhose. Hyacinth bean leaves are edible, but the beans (look just like little hamburgers) are poisonous to humans and pets.

Cherry tomatoes.

Sweet potatoes or yams - but the harvesting would be above, however. They make a nice looking vine over the wall though.

A fruit option might be boysenberries.

To trail on the wall and to let it hang down from the wall are two different thing. Not many plants have roots strong enough to support the weight of the whole plant pulling down the wall. To get the best result growing veggie this way you should build some sort of trellis structure for the vines to hang onto or else the whole plant might fall off from the top when it became too heavy.

ceth_k makes a good point. I never thought of that. The currant tomato idea might be the best, or some dwarf cucumbers; if nasturtiums will cascade downward, I would try that; also, hanging lobelia might do the trick, too. I appreciate the ideas put forth here. Thanks.

There is a way to solve the weight problem: put some nylon or wooden cross hatches sheets(same as one used as trellis) next to the wall first. Then you can tie down the ones with heavy foliage and/or fruits.

Most beans will also cascade if they have no choice. For example runner beans are not very enthusiastic climbers. Then you can always train them.

"....runner beans are not very enthusiastic climbers...." oh, my goodness. Do you grow runners, seysonn?

Like any other beans runners will do their best to grow upwards. Even if there is no vertical support they still won't trail down but will start twining round their own stems leaving you with a tangled mess.

Nasturtiums will trail but will need reminding every so often not to grow back towards the nice soft soil in the bed above. Make sure you get a trailing variety and not a bush or dwarf one.

Sweet potatoes would be beautiful. I also have seen trailing blackberries grown this way in California.

support is only needed for winter squash. beans and sweet potatoes will support themselves, as will do summer squash and tomatoes if kept picked. tromboncino should be good there.