Here's what I plant to do. Please let me know if you see a problem or have an addition to these plants. I'm going to build, out of wood, some box planters for each end and a bit along the wall. I thought I would line these with plastic to help prevent quick water loss.

Then I thought I would mix my own soil for them from sand, sphagnum peat moss, manure, and storebought bentonite clay, with a little free compost from the dump. Will this soil work for large balcony containers and houseplants too? Do I need to add anything else? I will put in some time release fertilizer too. I will look at the price for those water holding crystals to add, but I don't have much money for this project. I might put up lattice at one end for some shade and privacy too and grow some kind of flowering vine on it. Will it be a good idea to add worms? Will they reproduce and survive the winter out there in large pots?

Is there a hardy enough flowering perennial vine, that will grow on a balcony pot, in zone 5? Will a perennial sweet pea survive all winter in a pot in zone 5? Or climbing hydrangea? I have access to both of those for free.

What shrubs and perennials will survive a balcony in zone 5? Will hostas survive in a pot all winter? I do plant to put my tropicals and houseplants out there for the summer, too. And I'm going to grow several different daturas for out there, also.

For example - my lilacs are Zone 3/4 as are my blueberries (northern highbush). They looked like this the day before spring this year when it had the nerve snow:

They looked like this yesterday:

Some other hardy shrubs include the "pee gee" hydrangeas (ie., Hydrangea paniculata 'Grandiflora' or 'Tardiva' or 'Limelight', etc). These are hardy to Zone 3 and here was mine yesterday (still a baby but I am going on the 3rd year growing it):

My peonies are supposed to be hardy to Zone 2/3 and I have the old fashioned popular "Sarah Bernhardt" here:

I bought it last spring as a plant in a small pot and potted to the larger container (it had 3 buds but they never opened, which I figured would happen). This year it has 5 buds that are swelling so I am hoping they will open. It's tricky because of the sun issue, but right where they are sitting, they get morning sun right along that rail from sunrise (which is about 6 am now and will be an hour earlier next month, until about 11 am, when the sun goes up over the building).

I have asiatic lilies that are also Zone 3/4 and this is the 4th year in their pot. They're coming up now:

I have some tiger lilies that I tried for the first time last year and they are not up yet, but they are later bloomers (mid-summer), so they have some time. I saved some little bulbils from them last year and planted them in a little plastic pot that sat outside all winter. A bunch have started leafing already! LOL

I have some old old hostas dug from my mother's yard (I don't even know the name but they have a light lavender flower and plain green leaves - the plants were originally planted in the yard over 35 years ago). I have had them about 6 years in the same container and they are hardy to Zone 3:

Because alot of people who ground-plant them have problems with slugs and underground animals like voles that chew on their roots, they have taken to planting them in containers and sinking the pot. But other than that, they are pretty tough and come in all sorts of leaf shapes and colors, with large or small flowers in white or lavender or purple, some even fragrant.

I also have 2 clematises - both are jackmanii types - a "Prince Charles" and a "Madame Julia Correvon". These are also Zone 3s and I have them in a large 21" container. This is the Prince's 4th year and he has already gone nuts. It's Julia's first year after a winter and she is sprouting from the roots. Here is what they look like now:

I have lily of the valley plants that are hardy to Zone 2. Their foliage is all up and I'm waiting for the bloom stalks. They looked like this today (I have a couple containers with them):

So there are plants out there that one can try in the colder zones. In my case, I don't have to protect them except some mulch. But these could get some protection in areas where they would be marginal in a container just by placing them back against the wall and perhaps placing them in one of those foam ice chests and packed with more foam, the issue being that when the roots freeze, they should stay frozen and not be permitted to continually freeze and thaw. Ie., for hardy perennials, the roots CAN freeze (and inground they do), but they will need to stay frozen and then be allowed to slowly thaw into spring because freezing and thawing and then refreezing and thawing will do the damage and can kill (the root plant cells can burst).

I have a bunch of shrubs that are more marginal for me - Zone 5/6 in containers, and they generally do okay once established, eg., my weigelas, that I haven't had any problems with, although sometimes I'll lose some small stems to bud blast, but those are easy to prune off. The toughest are the evergreens, which I have to put wind breaks around, etc.

Three of the brugs of in a very large 2'pot. Can I plant the calla lilies in this pot with them or will the brugs take everything. If I feed the brugs constantly, will this burn anything else I plant in there with them. I'd like to put the fuschia in there too.

I have some more large pots for things, just no more dirt right now. I'll have to get some more for the ferns, if I grow them.

I'm getting a clivia and some hellebores soon from a trade. Will the helebores survive the winter on the balcony here? If that is in doubt at all, I'll bring them in. I know the clivia has to come in. I'm also getting a crown imperial fritilaria bulb from a trade. All these should arrive next week. I can't wait to see the frit in bloom! I also may be getting some dward bananas and white spider lilies from a friend. Not sure yet. Most of what I grow now is tropical and has to be winter stored, but that's okay. I'll put it all at my MILs. She has a great underground root cellar/pump room where her dahlias spend their winter.

It didn't take long. :-P

There should be a number of hardy ferns you can try. With respect to the Brug, some are dwarf but many can get pretty big. The callas are bulbs and you may need to dig them. They would probably be prettier by themselves. The hellebores should be okay - I've seen various ratings for them but apparently they have been known to survive in colder areas than originally thought. Especially if they are mulched/protected.

Not sure about many of the others which are bulbs but pretty ones though.

You have your work cut out for you! LOL

Thanks,
G

PS... pretty short growing season here.

For those in full hot blazing sun, before one of my sisters and her hubby had moved from a blazing sun apartment with balcony and bought a house, she was able to grow some of the ornamental grasses (eg., miscanthus) and bamboo well, asparaghus fern (it got huge), sunflowers, and veggies (although she had to continually water them). I would think the prairie type plants like daisies, asters, etc., can handle the hot dry better than most plants.