I'm sorry, but I am confused about your proposal. Are you talking about growing plants in nothing but bales of straw in a wooden frame or homemade self watering structure? On a second story balcony? How would that be transportable so it could be used in another season? What would grow to harvest in wet straw? Do you know someone else who was able to do such a thing?

Straw bale gardening is a thing. I'm surprised you haven't heard of it before.

Here is a link that might be useful: Straw Bale Garden Pictures

I would use the bales myself as it is a temporary thing. And you have a way to dispose of at the end of the season. Seems to make a lot of sense to me. Read up on tips and tricks using them. i know to keep them tied, and you have to use plants not seeds. Pack plant tightly after planting with the straw you removed to make space for the roots.

I did the straw bale gardening thing for two seasons. Results were mixed. The first year I did pretty well, the second not so much. When I used the straw bale method, I set the bales on their sides. I like that you can plant seedlings by spreading the bale and putting them in, but as the bale decomposes plants can get a little rickety.

The thing with straw bale gardening is the preparation. The bales need to be fertilized and watered a lot a couple of weeks before planting, so that they get saturated with the fertilizer. Also, your plants get their nutrients from the fertilizer, but also from the decomposition (rotting) of the straw from the inside out. That's why you need a lot of water, unless you live where it rains a lot. Once the plants get going, they grow pretty well.

After the first season my bales were pretty much rotted down to nothing. They make good compost but are not useable for a second season. My second year was successful but for some reason my plants didn't yield much. I'm in the square foot trials now, as last season was my first. I'm also planning on trying the rain gutter system found on You Tube. Hope this helps.
Grant

Well, I very learned something new in this discussion. Very intriguing. Thanks for that. My concern in your situation is how you would keep the straw evenly moist when it's sitting on tile. You'd need to make some kind of arrangement for runoff. If you do it, please report back.

thanks everyone for your feedback!

Hi Ohiofem,

I was thinking that I might use a plastic kiddie pool as a big saucer, drilling holes in the sides about 2-3 inches off the ground so that it doesn't sit in too much water. My concern (which sounds it may be the same as yours) is that they won't wick up water from the saucer.

Does anyone know how bales do with water retention? I'm worried that they'll dry out quickly on the tile, but the almanac says this will be a hot wet summer in the NE, so maybe it will be ok!

I'm thinking about trying a few bales this year. I was planning to wrap them in some industrial plastic wrap I have sitting around. If it seems too water-retentive later I can always poke holes in the plastic. Then I'll lay some burlap across the top, hit it with some high-N fertilizer, and wait a few weeks to plant in it.