Before I bought a single pot I sat at the kitchen table with the lease and a coffee and actually read the section about the balcony. It took maybe ten minutes and it saved me from two decisions I was about to make. There was a line about not attaching anything to the exterior of the building and a line about not obstructing the drainage channel along the balcony floor, which I had been planning to stand a large tub directly on top of.
Renting shapes small space growing more than the size of the space does. Everything below comes from that.
Nothing drilled, nothing fixed
The obvious casualty was wall mounted planters, which are exactly the thing every small balcony guide recommends because they use vertical space you are not otherwise using. I cannot fix anything to the wall or the railing in a way that leaves a hole, so that whole category is closed to me.
What replaced it was freestanding. A narrow shelf unit that leans against the wall under its own weight, and railing planters that hook over the top bar rather than screwing to it. The hooked planters are a compromise I keep an eye on, because in strong wind they are the thing I would least like to see go over the edge, and I bring them down or move them in when the forecast looks rough. That is a genuine limitation and not one I have solved elegantly.
Drips, stains, and the downstairs neighbor
The fastest way to make an enemy in a building is to water your pots and have it come out over somebody else’s laundry. Every pot I own sits in a saucer or a tray for this reason alone, even the ones where the plant would be perfectly happy without one.
The other issue is staining. Wet soil and organic matter sitting against a balcony floor leaves marks, particularly with a light colored surface, and marks are the kind of thing that comes up at the end of a tenancy. I keep pots up off the floor slightly on small feet or a tray, sweep out spilled soil rather than letting it sit, and I have never had a problem. My guess is that most deposit disputes about balconies are about staining and clutter rather than about plants themselves.
Weight is a real constraint
This one I underestimated. Wet soil is heavy, and a large tub full of it is genuinely difficult to move once it is planted. Balconies have load limits, and I have no way to look mine up, so my approach has been common sense rather than calculation: keep the heaviest things near the wall and near the corners rather than out in the middle along the railing, and do not line the entire outer edge with the biggest containers I own.
The practical version of the same problem is that I have to be able to lift these things. A tub I cannot move on my own is a tub that lives exactly where I first put it forever, including through a season where I discover the light is wrong there. I now think about liftability before I fill something.
Everything has to be able to move house
This is the part I did not think about at all in my first year. I planted a rosemary in a good sized pot, it did well, and then I looked at it while thinking about the end of my lease and realized I would be carrying that down a flight of stairs and into a car.
Perennial herbs are worth it and I still grow them, but I keep them in pots I can actually carry, and I take cuttings during the summer so that if a move goes badly I have not lost the plant entirely. Anything annual is a non issue because it will be finished by autumn anyway. What I avoid now is putting effort into a very large permanent planting that I cannot take with me and that the next tenant probably does not want.
The things I ask before buying anything
My checklist has settled into four questions. Does it attach to the building. Can it drip on anybody. Can I lift it when it is wet. Will it come with me. If a purchase fails any of those, I do not buy it, and it has kept the balcony simple in a way I have come to like.
There is one more thing I would add, which is to talk to whoever manages the building before you assume. I asked mine about the railing planters rather than just hanging them, and got a straightforward yes with a note about wind. That conversation took two minutes and means I am not quietly worrying about it every time the weather turns.
What renting actually costs you
Being honest about it: renting rules out vertical growing on walls, rules out anything permanent, caps the size of your containers at what you can carry, and adds a layer of care about drips and stains that a homeowner with a yard never thinks about. That is a real reduction in what is possible, and I do not think the answer is to pretend otherwise.
What it does not rule out is a row of herbs you cut from every week, a couple of pots of leaves, and one big tub with something fruiting in it. That has turned out to be enough to keep me interested for four years, and none of it would survive a dispute at the end of a tenancy.