This is an idea that I just got turned on to:

Turn cinder blocks on their sides so that the holes are open to the sky. Then fill the cinder block holes with potting soil and plant your seeds or seedlings.

I understand that tomatoes do very well in the cinder blocks. I think herbal plants located just outside of your kitchen door would be great as well!

Sounds good, may want to stack them two high to accomodate deeper roots. Also be aware that all that surface area exposed to air and no bottom will make more frequent watering necessary to prevent drying out the roots.
You may try the same thing with pole beans or peas or cucumbers on your balcony. Just put up a piece of re-mesh or 6"x6" field fence as a trellis. The large openings in the fence let you reach through to pick produce without going around (off the balcony?). Even squash can be grown vertically this way, if they get too big make hammocks for them using old pantyhose or other scraps of lightweight mesh material. Just tie the ends of the hammocks to the fence wire for each veggie.

Those 2-hole concrete bricks don't hold water very well -- they're worse than terra cotta pots in hot/dry areas.

I've tried planting in them and it doesn't work very well for plants that are heavily dependent on water, like vegetables, even here in the PNW. Some herbs might survive, or some succulents.

A better use for the cinder blocks would be using several to form a bed -- more soil available that would hold more water.

You do mean cinder blocks and not cement (concrete) blocks right?
Cinder blocks are less porous than cement blocks but they are hard to find here

There was a recent thread on grow bins which are really just plastic storage bins full of potting soil with a tube in them to fill up a water reservoir in the bottom.

I don't get so fancy.
I sometimes use 5 gallon plastic pails as planters. The real trick is to put drainage holes in the sides about two or three inches up from the bottom. It lets you water them well but if over watered it just drains out. That prevents root rot or damping off happening to your plants. It also lets some water stay in the bottom of the soil to act as insurance against drying out if you miss watering it for a day or two.

I say 5 gallon but the pails that are half that height, the 3.5 gallon ones work well for me too.
I just like the 5 gallon ones because I don't need to water them as much.

IMHO, plastic pots/buckets are much better than the blocks. They hold moisture better. And, what may be more important on a balcony, the weight of the blocks can be a serious factor. If the supporting structure isn't build sturdy enough or has hidden damage, the whole thing can come crashing down.

One other structural issue -- blocks containing soil in direct contact with wooden decking material will speed up the decay process. If the plants are properly watered, the wood under the blocks never dries.

Buckets/pots are easier to move around as needed. Easier to store during off season.

With pots and buckets the containers can be sized to meet the needs of the individual plants. While there are some, as a general rule most vegetables require more root area than a cement/cinder block can contain. FWIW, I've planted holes in the blocks, several times. Even with ornamental plants, they don't do as well as those planted in pots at the same location.

Using the blocks to make raised beds, then, planting the holes with small trailing herbs and such works OK. The soil in the bed helps temper the water loss from the blocks.

Just 2-cents.
Lee

And they're heavy to carry upstairs.

Good point Susan.
One of the other reasons I like plastic pails is that I have a good supply of free used pails from restaurants. I just have to rinse them out and put the lids back on them for storage. A swish of bleach water solution and they are sterile again too.
It is nice to get them the same style so they nest inside each other and stack easy in a corner until you need them.

I use them for everything, garbage pails, mop buckets, slop buckets, livestock watering buckets, storage containers and even planters.

The only drawback is that they eventually go brittle and the bottoms crack so I consider them as expendable items.
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So long as they stay freebees to me that is fine, if I ever have to pay for them then I would be likely changing my mind about them being disposable items and choose something more durable.

(The local homebrew beer and wine supply store wants over $20 for new ones, to me that is a ridiculous price!)

edit: I think they go brittle from exposure to UV light (like from the sun degrading the plastic) but they get brittle in very cold weather too, a normal thing for most plastics.

Check out this thread I posted about gardening on my balcony.
I am getting a lot of yellow tomatoes, squash, cucumbers and Alexander strawberries. Now the red tomatoes are turning too!
http://forums.equipped.org/ubbthreads.ph...true#Post173395