I took a couple of pictures of my broccoli plants a few days ago. One is in
a 4 gallon bucket. The other is in a 5 gallon bucket. They were both started
from seedlings at about the same time at least 8 weeks ago.

As you can see, the 4 gallon one is quite a bit smaller than the 5 gallon
one. Also, the part of the plant that we eat has already "gone to seed" on
the 4 gallon one.

Silly me, you know I never realized that broccoli (the "head" that we eat)
is actually a many faceted flower! Well duh, that's why they're called
"broccoli florets". Well anyway, the florets on my 4 gallon broccoli were
obviously left on the plant too long. I was hoping the broccoli head would
get bigger. But it just started to spread out and develop flower petals.

You can also see that the 5 gallon broccoli is much larger. I think that its
flower has the potential to grow quite a bit more. We'll see.

I am convinced that using anything less than 5 gallon buckets is not the way
to go on a balcony, unless you want small plants.