By dirt I am hoping you mean 'potting mix' rather than actual soil.

To use the styrofoam or not (or any other filler material) is really a matter of priorities. If the weight load on your balcony is a concern then this would argue for using them. If the cost of potting mix is a concern this may also argue for using them.

If neither is of major concern I wouldn't use them. All they do is reduce the growing space your plants have.

You will find that some plants like lettuce do just fine in shallow potting mix. As little as 3" will work, 6" is better and more is a waste as far as I am concerned. Peppers will also do fine in 6", 8" better. Tomatos and vine crops like squash, cukes and mellons will reward you with each inch of depth you provide and a 5 gallon bucket I consider the practical minimum. I wouldn't reduce the soil depth or volume for these crops at all with the containers you mentioned.

Just my 2 cents.

This is one of the many questions for which there will be a WIDE range of opinions....so watch out! lol You'll have to 'weed' through the answers to see what seems to make the most sense to you.

I've used the packing peanuts in the bottom of very large containers for ANNUAL plantings that really don't seem to need all of the soil volume. Since I use a very coarse textured potting medium, my plants tend to develop a very vigorous root system (quickly) and by the end of the season those roots have completely engulfed the peanuts, using them (literally) as just one more growing medium. I would never use cans, bottles, etc. for my purposes.

Again, I only do this for my largest annual containers, which I think are about 36". All of the others are filled with the potting medium.

However, I would also suggest that veggies will need every single bit of space in a 5 gallon bucket and that you will be selling them quite short by eliminating a bunch of the soil. I'd urge you to fill up the whole container with a good, coarse-textured potting medium built to remain productive for a nice, long growing season.

Long term (permanent) plantings should be put into container sizes that match the size of the plant, then moved up as the plant grows.

I did the styrofoam peanuts a few years ago and regretted it. As far as I know the peanuts at the bottom of a container do not aid in drainage and at best all they do is lighten the pot somewhat. But why not just put in less soil or use smaller pots? The worst part of styrofoam peanuts comes the next year when you need to dump the soil in the pot and recycle and/or compost it. You'll end up having to pick all those styrofoam peanuts out by hand. For me it was a huge PITA. By now I think all my containers are now styrofoam peanut free.

Thanks for the responses. Yes, Justaguy2, I did mean potting soil, amended with organic matter (I have a good source of composted leaves). I made that whole garden dirt vs. potting soil in containers mistake (consider it a hard knocks type of mistake--lol) several years ago. Now I know better. I am concerned (I'm not sure if it is a justifiable concern) with pot weight, as well as with the cost of potting soil. I assumed that this would be a topic with widely varied opinions, but I thought I'd throw it out there anyways... I also appreciate the information about how big a container/how much potting soil is necessary for tomatoes, etc. I was under the false impression that cucumbers could go in a smaller container, and I appreciate the heads up! Thanks guys!

There's also an incredible range of veggie plants that are bred for compactness and/or container growing. You ought to do a little bit of research on those varieties.

Attached is just one link citing varieties, but there's plenty of information on line.

Here is a link that might be useful: Click here!

I plan on planting 3 "BushSteak Hybrid tomato plants purchsed from Burpee in 3 separate containers. I purchased Miraclegrow potting/container soil to plant them in. I have Miraclegrow tomato feed also. I Have a multi-question: How often should I water them? How often should I feed them (the potting/container soil contains 3 months of fertilizer). and lastly, I read that all the leaves must be pulled off after they start flowering.

How often should I water them? How often should I feed them (the potting/container soil contains 3 months of fertilizer). and lastly, I read that all the leaves must be pulled off after they start flowering.

You should water them often enough that the potting mix never dries out. Tomatos consume a lot of water each day, particularly when they are large and the weather is hot and windy. Tomatos are particularly prone to blossom end rot and the cause of BER is the plant not being able to deliver sufficient calcium to the fruits. If the potting mix dries out the plant cannot deliver the calcium. You might also consider adding calcium to the mix as potting mixes do not contain ample amounts of it. Lime will add it.

Feeding tomatos is a bit more subjective. You should be fine using Miracle Grow Tomato fert according to label instructions although there are reasonable variations such as taking the amount per feeding the package indicates and using it at a lower strength more often. For example if the package says use 1 teaspoon every other week you could use 1/2 teaspoon every week. Many believe more frequent feedings with a reduced amount of fert helps even out the nutrient availability.

The potting mix may say it feeds for 3 months, but it doesn't. It is a marketing gimmick. Fertilize as if there were no fertilizer in the mix.

Lastly, removing the plant leaves after flowering is some of the worst advice I have ever seen regarding growing tomatos. Wherever you saw that advice I would say it is safe to ignore anything else that source says. The plant's leaves are it's photosynthesizing organs. No photosynthesizing, no energy for the plant to mature it's fruits.

In particularly sunny areas the leaves serve a second function and that is to prevent sun scald of the fruit.

Leave all of the leaves on the plant please.

Thanks Justaguy2, I thought that advise about the leaves was kinda off the wall and way out in left field.
I've posted several other questions around this forum re growing tomatoes. Your's was the first response. Thanks for the advice. Also, I thought that 3 months was just a sales gimmick, and you confirmed it.

I read somewhere on this site to use a dolly to move pots and I havent had trouble since. I bought one for 19.00 at Lowes and it works slick. No packing peanuts for me.
Be sure to read the thread on soil amendments.

Sorry its not sil amendments. It's soil in container ect thread III