I'm not familiar with container gardening, but I know how painful it is to thin those tiny, little seedings to the correct spacings. Unfortunately, there's nothing to be done but bite the bullet and pull out the extra plants.

Every time I've tried to squeeze just a bit more into my limited garden space I've either had disease or low production. Thinking back on those experiences helps keep me disciplined about spacing plants correctly -- either by planting only the correct number of seeds at the correct distance apart or by thinning.

As for root crops, not forming roots can either be a spacing issue or a fertilizer issue -- too much nitrogen can give you overly-vigorous leaves at the expense of the root development. And, of course, it can be a combination of the two.

Good luck with your containers this year.

kawaiineko,

I know what you mean about that section. Went through all kinds of idiotic, stupid, thoughtless, nasty posts once when I offered a suggestion for a container mix that was not what Al and some of the others use. But I grew great plants in it!

Your best bet is to look on the back of seed package. It usually tells you how close to plant seeds, both between plants and between rows. Things like radishes and carrots you can grow with an inch or two between plants and double that for rows. Onions, depending on the variety, will take 2-3 times as much room.

Mike

Well, I've not done too much container gardening, but what I would do if I were to try it is work with a couple of thoughts in mind. First, I would look up the veggie in question, either in a gardening encyclopedia or else right on the seed packet. That would tell me the proper spacing if I were planting in the ground. Then, since planting in containers is different than planting in the ground, I would place my plants a bit further apart. That's because the more rapid changes of temperature and moisture in containers can be stressful, so I would want to give the plants a bit more space. But like I said, I haven't really done a lot of container gardening. Those are just my thoughts. :) Hope they help!

Sunni

Mike I remember the rudeness on that forum to your post. I stay off of it now and just smile. Oh but I do grow in my own mix in my containers. I grew Pock Choi in crushed dry tree leaves and worm castings last year on a lark. It was fun and it grew pretty good to
Kawa Do not give up, it can be hard ,but look at all you have learned. I can really tell by your post you have learned a great amount

Curt

Get a copy of Square Foot Gardening by Mel Bartholomew. He provides guidelines for plant spacing based on a square foot garden space for each type of plant. For example, carrots are 3 inches apart or 16 per square foot. Spinach is 4 inches apart or 9 per square foot.

If you want to try to plant seedlings close, go ahead and experiment, keep notes and adjust as you go.

Have fun,
Rick

Curt,

I pretty much stay away from it also. They worship Al. He's a nice guy but his minions simply refuse to look at any other ideas. Narrow minded is giving them a compliment!

Mike

Don't forget that even if you do overcrowd something like lettuce or beets, you can eat the thinnings as baby leaves.

Kawaiineko, you have been asking a lot of specific questions lately related to nutrients, fertilisers etc. Although this is interesting stuff it sounds as if you are possibly overthinking your gardening. I would just get on and try things out, according to the packets or a basic book, without worrying too much about getting it theoretically perfect before you start. Some of your worries, like your boron question, are probably about problems which will never happen. Vegetables want to grow and will do their best to do so. As you get experience you will soon get the hang of it. Many of us have grown veggies for years with low tech no fuss methods and have got perfectly usable crops. Sometimes things grow wonderfully, occasionally they don't. So give it a whirl. And definitely don't be 'afraid' of anything in vegetable gardening. This is supposed to be a relaxing activity. Enjoy it. Best of luck, Flora.

I agree with everything said above but would just like to add one thing. Sometimes I plant small veggies that will grow and harvest quickly between larger and slower growing crops, like radishes in between my tomatoes. That sates my desire to fill up my garden with plants while still giving enough room to the tomatoes when they grow up and need it.

It would be of great help if you would post specific dimensions of the container(s) in question and what specific vegetable you want to plant in it. That way experienced gardeners could offer you specific answers. For example, an Earthbox will ideally hold 2 determinate variety tomato plants or 1 indeterminate, 2 rows of leaf lettuce or 4 heads of head lettuce or 6 chard, 12 beets or turnips or onions, 3 rows of Nantes-type carrots, etc.

Vague generalized questions tend to get vague and generally unhelpful answers.

As Flora said above, thinning. The simple solution to overcrowding is to plant as you wish but then be prepared to actively THIN as required once the plants gain some size.

Alternatively, use transplants - grow your own from seed - rather than direct sowing when planting a container. When gardening in containers, transplants are much easier to space correctly than if you use direct sowing.

Just like most of the forums here, the Container Gardening forum offers a wealth of information. Especially so if one is willing to use the search function first rather than just posting the same questions over and over. ;)

Dave

Hi,

I agree with the above poster who suggested using the square foot gardening method for spacing. Basically, you use the measurement from the packet for the plant spacing, and use that in both directions. You disregard the row spacing measurement. So for beets, say. If it said plant seeds 4 inches apart in rows 12 inches apart, you would just go 4 inches in either direction and make a grid. I would recommend an inch or two boarder between the edge of your pot and where you plant the first seed. Also, if your pot is smaller at the bottom than at the top, I might increase the size of the border, particularly for a root crop that has to grow down. I often picture in my head how big the final plant will be, to determine if it will fit in my pot.

Your problem with the root crop not bulbing up is not uncommon. Many of us have experienced it and it may not be completely an over crowding issue. I don't know the magic answer, but so far I've been successful with Turnips and Daikon, but unsuccessful with Beets and Rutabega. And I'm growing in the garden, not in pots. Sometimes it helps to know that it's not just you that has the problem. :)

Best of Luck with your garden.

Susan

Here is a link that might be useful: Square Foot Gardening Plant Spacings FAQ

Well basically what I need help with is how many square feet are in a 1 gallon container and then multiplying that times the gallon containers I have (which are 10 gallons, 18 gallons, 30 gallons, and 32 gallons).

I know that with Square foot gardening based upon how many square feet there are with the 'box' that is used, that determines how many plants can grow there. However the thing I'm confused about is I don't know how many square feet is the equivalent of a 10 gallon container, a 30 gallon container, etc.

Somebody asked for the dimensions of my containers well here they are:

10 gallon:

Shape-rectangular; color-medium blue; type-plastic storage
container

Length-19" (1-1/2 feet plus the leftover 1 inch)
Width-13" (1 foot and 1 inch)
Depth-12" (1 foot)

18 gallon container:

Shape-rectangular; color-medium blue

Length:23"
Width: 17"
Depth: 15"

9-1/2 gallon container

Shape-rectangular; color-dark blue

Length: 19"
Width: 14-1/2" (1 foot, 2-1/2 inches)
Depth:11" (1 inch shy of a foot deep)

30 gallon

Shape-rectangular; color-gray

Length:28-1/2" (2 feet, 4 inches)
Width:19" (1-1/2 feet plus the additional leftover inch)
Depth: 17" (one inch short of 1-1/2 feet)

32 gallon

Shape-rectangular; color-gray

Length: 30-7/8" (2 feet, 6 inches)
Width:20" (1-1/2 feet plus the leftover 2 inches)
Depth: 17-1/2" (just shy of 1-1/2 feet)

My other question is somebody said to disregard row spacing with container gardening. I know this but if the container is big enough, would you be able to do two "rows" or would this be overcrowding the plants?

What I've done in the past is two rows, one at the top of the container, the other in the bottom half of it, leaving a gap in the middle so the plants will have room to grow. However, would doing this be overcrowding them, even if the container seems big?

I also have some circular pots with a 14" diameter rim, that are about 4-1/2 to 5 gallon size. They're light green in color, and a self-watering variety.

If this isn't specific enough information for you, I don't know what is.

However the thing I'm confused about is I don't know how many square feet is the equivalent of a 10 gallon container, a 30 gallon container, etc.

Sq. Foot is just the length multiplied by the width (in feet). Depth and # of gallons are not relevant. So if you has a container that was 3' long and 2' wide it would have 6 sq. feet.

EX: A container that is 19" long and 14" wide is basically 1.8 sq. feet.

19" div. by 12" = 1.58' and
14" div. by 12" = 1.16'
1.16' X 1.58' = 1.832 sq. feet. Call it almost 2 sq. feet.

You can do the basic math on all of them but all your listed containers are 2 to 4 sq. feet. The last one on your list is 4.28 sq. feet.

The formula for computing the sq. feet of a circular pot is
Area=Pi X R X R where Pi=3.14159 R=radius of the circle. So a 14" diameter pot is basically 1 sq. foot for all practical purposes (1.05629).

Dave

kawa; I will try to help out. The problem with gallons is that it is a volume. It can not be used for square foot? A gallon can be tall and thin or short and thick . Square foot is the area. Area is the length times the width.
on your 10 gallon container you can use 1.5 foot times 1 foot to get 1 1/2 square foot with some left over do not use the depth. maybe if you think of square foot as the size of the top of a table it will help the size of the table is the same for short legs or long legs.
18 gallons 23 x 17 this one we can call 3 square foot
her is the math 23x17 inches =391 square inches to change square inches to square foot we divide by 144 and come up with 2.71 square foot
A square foot is like string on a table one foot on each side no matter how you move the string on the table without crossing or lifting you still have a square foot.
I hope this helped as I am no teacher

Curt

If yer too dumb to do basic math and geometry that was taught in grade school or have the inability to follow simple instructions from a seed packet bought at yer local walmart, i feel bad for you.

Just go ahead plant yer stuff, if it is planted to close and chokes out the sun, water and nutrients from the plant next to it. Plant them farther apart next year! lol

Jim

When I taught my kids how to thin something like onions I gave them an onion and showed them to set it on the ground and put 2 fingers before the next one.

Wow. I am just shocked by the needless attack on the OP. If someone is having trouble with something that seems basic to me, I give them help, I don't villify them for not knowing. Attacking someone for not knowing something is unhelpful, useless, and generally not part of what makes this such a great forum. Actually, I think the whole process here would fall apart if we did that on a regular basis. No one would ever want to ask a question for fear someone else would tell them they are stupid for asking. Good gracious!

I havent read the other posts so forgive me if I repeat anything here.

I too am a new gardener and I find that you have to basically think about root space, any root veg you need a deep pot, and anything like lettuce and such you need wide space.

There are actual spacings recommend usually, but I havent really found them to be helpful for containers as they're usually about row spacing.

Its all experience and you just have to give it a go, and fail/succeed a few times :)

Pak choi, is a good one though its by far the easiest thing to grow (for me) once it gets going. (ie dont let anything eat it)

Good luck.

kawaiineko_gardener pay no attention to any jerks posting in your thread. There has been some good information given to your questions though. Keep in mind that there is always some trial and error when it comes to growing anything as there are lots of variables. Also keep in mind that if you plant too many you can always remove some to make room for those that remain. Nothing like picking and eating baby carrots or beats to make room for others to grow.

Here is a simple solution to planting your containers. Go to Garden Planner.

Type in the size of your container in the box provided ie: 2 X 2 or 2 x 4 etc. Then scan the little pics of all the vegetables provided and drag the pic of your choice into the box on the screen. It will show you approx. how many you can plant in that size box.

EX: a 1 sq. foot container can hold 9 beet plants, OR 4 heads of lettuce, OR 1 squash plant.

It isn't perfect. It still assumes proper soil, water, and regular feeding. But it will get you started.

You have several very small containers. For best success with container gardening I'd suggest you invest in some larger containers like 2' x 4' minimum and even larger if you have the space. Personally I find containers that are 3' by 5' by 12-18" deep to be ideal. It is costly up front but the quickly pay for themselves.

Dave

Thanks for the link digdirt. Its a little limited but still functional. I wish someone would come up with a program that would allow me to input the dimensions of my yard and add raised beds and lay out my raised beads and show where I have trees and bushes too. It makes everything easier when you can see it all and plan it.

Cool!!! I clicked on "Design your Site Map" and I can fit half of my back yard in it at a time. If I want I could do two for the back and one each for the side yards and tape them all together for a complete yard map.

Thank you so much.

If math is something you're good with fine. However to assume that because it's your forte, it should be the strength of everybody else around you is just stupid.

I know how to follow instructions on a packet. However I didn't know the formula for square entailed basic math until I looked it yesterday. On top of that I didn't anticipate the complication of having to convert it from area to volume, which just confused me further.

Regarding the containers, I'd love to invest in larger sizes, but I don't know where to find these. Normally the containers I find they specify how big they are with the capacity they're able to hold with gallons, not their dimensions in measurements such as feet,yards, etc. This isn't to say they don't give those measurements, but normally those measurements (length, width and height with regards to the feet size you mentioned) but these are normally in inches, which means I have to convert it to feet.

Unfortunately space is a problem I have a very limited amount of it to work with.

With the size containers you recommended, the 2' x 4' and the 3' x 5' generally how many gallons are these (40, 50, etc.) As stated above if you specify the capacity they're able to hold rather then their dimensions with length, width, and height in feet, it'll just make them easier to find as that's how they're normally listed when I buy them. (In gallons). Also are these available at places such as Walmart, or a local hardware store (Lowe's or Home Depot for example).

One last thing, I know this is totally offtopic, but I grew 2 squash plants in a 10 gallon container. Somebody told that is too small to grow a squash plant in (mine were just zucchini). That if you overcrowd squash plants,
you're more likely to get more male than female flowers on the plant, and that this causes a problem with pollination too? I did get squash on them but they were very small, and then they just shriveled up and died. I'm wondering if the problem was because of growing too many plants in too small a container, lack of pollination by bees, insufficient fertilization or a combination of all three?

I don't know what caused them not to fruit properly, as there a number of reasons that could've caused the problem. I don't know if it's one problem, or multiple problems.

thisisme - glad you liked it. The link has been posted here many times before and while it isn't perfect it is plenty of information for starting basic gardening.

Regarding the containers, I'd love to invest in larger sizes, but I don't know where to find these. Normally the containers I find they specify how big they are with the capacity they're able to hold with gallons, not their dimensions in measurements such as feet,yards, etc. This isn't to say they don't give those measurements, but normally those measurements (length, width and height with regards to the feet size you mentioned) but these are normally in inches, which means I have to convert it to feet.

Simple. Just take a measuring tape with you when shopping for containers and measure them.

I can only tell you what is available around here but yes, Walmart, Lowe's, Home Depot, and most garden nurserys will carry containers that are 2' x 4' (24" x 48") or in that ballpark. Larger than that usually has to be ordered (and yes any nursery will order them) or built. There are many places online where you can order them but shipping is high

Walmart also carries hundreds of plastic storage containers that can easily be converted to planters. One example is the Underbed Storage boxes that are 2x4 and 3x4 and 6" deep. With multiple holes drilled in the bottom of them they work fine. There are also all sorts of the larger Rubbermaid Totes sold in most any store including Dollar Stores that can be made into planters. Shop the plastic storage asile rather than the garden center.

Walmart was selling off all their Halloween and Christmas ornament storage totes that are huge for only a couple of dollars here after the holidays. As long as you didn't mind their yucky colors they were perfect. And there are always Earthboxes and all the similar copycat containers available.

You have to learn to think creatively, to think outside the box so to speak. You also need to quit thinking in "gallons". With the exception of the really large plants like cucumbers, indeterminate tomatoes, squash, etc. "gallons" isn't usually relevant.

I grew 2 squash plants in a 10 gallon container. Somebody told that is too small to grow a squash plant in (mine were just zucchini). That if you overcrowd squash plants, you're more likely to get more male than female flowers on the plant, and that this causes a problem with pollination too? I did get squash on them but they were very small, and then they just shriveled up and died.

A 10 gallon container IF it was at least 2'x4' is ok for two squash plants IF they get really good feeding and very careful watering. But if not then yes it is too small. Or if it is only 1'x2' and really deep then it isn't big enough for 2 plants. Some plants spread out and some grow tall. Tall plants need depth. Spreading plants don't.

But the size of the container is only one factor. Like already said repeatedly container gardening requires proper soil, proper watering, and proper feeding. Any of those factors is far more likely to cause you problems than the size of the container. The most likely cause of problems with squash is BER which is just what you describe OR lack of pollination so you have to hand pollinate. There are FAQs here about both.

Container gardening is unique (the main reason it has its own forum on all gardening websites). It isn't just a "little mini garden" in a box. It is a totally different way of gardening than that done by most of us who garden in the ground. It is more complex, requires far more care and attention to detail - especially watering and feeding, it has much less room for error, and it is generally less productive. So most information available about gardening applies to in-ground gardening, not to containers.

You do much better if you focus on information specific to gardening in containers or Sq. Foot Gardening (which is just gardening in a bigger container) and there is tons of it available on the web.

Dave

kawaiineko_gardener the last time I was at Home Depot in the section where they have concrete they had 24"X36"X8" Black Plastic Utility Tubs. At the time I thought they would make a great container to plant an herb garden in if they had some holes in them. I looked online and they do not have them on their web site.

There are some being sold just like them though at the link below. I would check at your local Home Depot and Lowe's.

Here is a link that might be useful: Black Plastic Utility Tubs

I've taken to following the square foot gardening guides for planting my vegetables in containers. As far as the spacing for plants or seeds go, I only consider the surface area of the container. If it's 12 inches in diameter, I equate that to the square foot rule and plant according to their recommendations.

As for failures, there are no guarantees in the garden. I failed with each planting of beets last year, although I sure loved the greens. Will I try them again this year? You bet. They're one of my favorite crops. Perhaps I'll let the soil warm up more before planting this year, or maybe not. For sure I'll fertilize them, which is something I failed to do last year. As one poster said, gardening is to some extent trial and error. Or as the kids say today, it has a steep learning curve. :(

Best of luck with the new gardening season, may all of our crops be bountiful!

kawaiineko_gardener - you said 'Unfortunately space is a problem I have a very limited amount of it to work with'. Can you tell exactly us how much space you do have? I am wondering if you could have some in-ground beds which would help you avoid all these continer-related complications. At the top of this post you say you are using container sizes up to 30 gallons. I would have thought that if you are using that size plus others they would be sitting on an area big enough to put in a small raised bed, either dug out of the ground or on top of it, which would be a lot easier for you to manage. Easy and cheap to build out of scrap wood or blocks.

It takes a long time to learn to think like a plant! :) And then you have to learn how to think like about 40 different kinds of plant... Yup, gardening is hard to master! But where would the fun be without the challenge?

For what it is worth, I once converted one of those clear plastic storage containers into a planter for some herbs. It worked great, but I neglected to bring it in and the plastic shattered the next spring. I think the other colored types of containers have hardier plastic, though. As for the fruit drop on the squash, that sounds like plant stress, though it could be lack of pollination too. Even when you have a whole garden to plant in, it can be very tempting to try to stick in a few more seeds/transplants than you really have room for. But I've come to find that if you give the plants enough space, one thriving plant gives you more produce than two crowded, suffering ones!

well with such a place like Walmart, would they carry the larger varieties of containers recommended (the 3' x 5')

Also somebody suggested that I divide my space up into
square foot blocks. How exactly would I do this? And then when I do, if a container contains more than one square foot, is that how you would do your plant spacing according to what the packet specifies?

The thing I'm confused about is the formula somebody told me for square footage was length x width. They then said 'this for volume, what you need is the area'. So what is the formula for square footage for area not volume?! I don't know! If I did, I wouldn't be asking.

I'm still extremely confused about the square footage formula. can somebody just tell it to me again in plain English, cause I tried to figure it out just by skimming thru the posts, but it makes no sense to me.

When this formula is specified, please do so with the area, as somebody told me this is how you find the square footage of something.

An example is some of my containers are like
That is the formula given to me, is that the formula for finding square footage? It makes no sense to me. it's geometry, which I don't understand at all. It's basic math to many people here but it's clear-as-mud to me. I'm horrible at math, especially geometry and formulas.

Somebody said that with the dimensions of my containers, they're all between "2 and 4 square feet". For somebody who knows how to find square footage can you please tell
me the square footage of each? the reason I ask is this is because I"d like to use the link given to figure out how much can be planted in each of my containers, but I can't do that unless i know the square footage for them, which I don't.

also what would be the square footage for the larger containers that were recommended (the 3' x 5' and the 2' x 4')
Area=Pi X R X R where Pi=3.14159 R=radius of the circle. So a 14" diameter pot is basically 1 sq. foot for all practical purposes (1.05629

Area is not going to help so much that you need to get it that precise. Some crops are shallow rooted (baby lettuce) and others really, really deep (beets). The extra depth of a tall container isn't really going to help the lettuce.

Part of the art of french intensive gardening is matching these plants together in a way that allows each plant the most room it needs and best conditions possible while getting as many plants on one place as possible.

I won't attempt to give you specifics since I have never gardened anywhere as cold as zone 5, and different plants and varieties react very different in different places. Every gardener's experience is different, so keeping reading and asking questions, but accept that there's no exact formula for success. Even every year brings something new.

If your situation permits you to set up a permanent garden space and conditions, you will be able to experiment from year to year better. Even if not, keep careful notes. What plant variety went in what kind of container of what kind of size in what spot with how many hours of sunlight on July 1st... etc. Then while you are dreaming of spring during the dark of winter, you can review what worked -- and what didn't -- and then make plans for next year.

P.S. - The formula for the SURFACE area of a rectangle is length x width. To get the total area, it's length x width x height.

As explained in great detail above the square footage of any container is its length multiplied by its width. A 3'x5' container has 15 square feet. A 2'x4' container has 2x4 or 8 sq. feet. Take a 12" (1 foot) ruler and lay it out on the top of the soil in the container. A 3'x5' container will be 5 feet long and 3 feet wide. This is the most basic math there is.

I even computed the square footage for you of the containers you posted above.

We also addressed the issue that for square foot planting volume and depth are not relevant. Volume is not relevant to sq. foot planting. You do not worry about volume. Forget about volume. It doesn't matter. Can't say it any plainer than that.

You really are WAY over-complicating this very simple issue.

Draw a 3'x5' box out on paper. Go to the Sq. Gardening website. They have pictures posted on many of them.

Dave

kawaiineko_gardener gardening is almost as much of an art as it is a science as it is a game of chance. You can have all the variables worked out up one side and down the other and still fail. Another person can sometimes do everything wrong and succeed beyond their wildest imagination. Two different people and sometimes even the same person can do the same thing in two different places and have two totally different results. Sometimes its the same person doing things the same way in the same place and the crops just fail when before they had total success. They don't know why it does not work in one place or why it worked before and no longer does. All they know is they have to learn how to do it differently to make it work.

We all study hoping not to fail at anything but every good gardener has some crops fail or not do well. They learn something from it and make corrections the following season. You can think and think and think and think and think and I am not telling you not to think. But there are some things you can only learn from doing and doing and doing and doing and doing. Then you think about what you did and what the results were and what you can do to make it better. And the next season you make it better and the next season you make it better and the next season you make it better and the next season you make it better and the next season you make it better.

There is no way to skip ahead five or ten seasons. You are going to have to do it and take notes and get better just like the rest of us. Yes it helps to ask questions and yes you have to plan ahead. Just don't get so caught up in trying to do it perfect. You will have failures and successes no matter how much thought you put into it. Gardening is one of those things you learn by doing. In time you will have more successes and less failures.

As time goes by there will be some things you will decide not grow because they are too much work or fail to often or take to much space. Some things you will grow just because they are easy. Some things you will grow just for the fun of it. Some things you will grow just for the challenge. Some insects will learn to hate. With some learning and asking some questions and with a little luck and some hard work in time you you just may learn to really love gardening. That one thing will be all you will need to keep you studying and learning and asking questions and keep you taking notes so that next season your garden will be better than the last.

Lastly there is no perfect way. Pick a way to do it and learn from it. If it works think of how you can make it work better. If it does not work think about ways to make it work next time. One thing for sure. You are not going to become a master Gardener by thinking about it. Master gardeners get that way by doing better each time they do it. I have watched certified master Gardeners talk about their crop failures and how they could not figure out why they failed. Then they talk about trying different varieties for years and doping thing differently until they get it right. Even they could not jump ahead to success. They got there by doing and learning from doing and so will you.

Sorry this was so long and preachy. I guess its the preacher in me.

There's a great book called _The Bountiful Container_.
It has two authors, Stuckey & McGee. Published 2002.

They go through a list of crops and give container size recommendations and tips for each crop individually. They cover vegetables, fruit, herbs, and edible flowers. They also direct the reader to specific varieties which are well-suited for container gardening. This is the best book I've seen so far on growing edibles in containers. It will be most helpful to those people growing the same crops covered in the book.

Last year I planted vegetables in buckets on my porch and had a small in-ground garden, and I completely agree with everyone who says it's a whole different type of gardening.

Check the library to see if they have or can get you a copy. My local library didn't have it so I requested the copy owned by another library in my state. Was able to pick up and drop off at my home library.

Hope this helps someone!

Edie

I live in the Phoenix, AZ metro area. The soil here ranges from a compact clay to caliche (a compact cement like soil). Some folks are lucky enough to have a thin layer of topsoil that could manage a garden. So many people around these parts rely on raised bed and container gardening. As such, the University of Arizona's Master Gardener's Manual recommends different methods of growing in containers. (Sorry...this is a long winded and winding response). Anyhow, the manual is online and it has recommendations for spacings of intensive plantings like you might plant in a raised square foot bed or in a container. The link is below.

Here is a link that might be useful: Arizona Master Gardener Manual on Intensive Gardening Methods

alabamanicole misspoke there, lenght by width by height is VOLUME, the same thing that gallons measure. We've established that you only care about the flat top part of that (AREA) for plant spacing, which is measured in sq ft, among other units. I only mention this because I can see how much confusion that one sentence could cause!

Maybe you should Stop trying to think in terms of Square Foot Gardening. That is just one method of thinking about how to grow your garden that happens to be popular right now. It also seems to be a method of thinking that does not work for you. Everybody thinks differently.

Let's go back. Last year you got lettuce and Pak Choi, that's great! Try to plant them the same way this year. Maybe add a few other Asian greens and grow them that way too. Like Misome, Tatsoi, Mizuna...

Otherwise, don't try to do math in your head or on paper. Just go to one of the helpful links above like the one from brismith70 and find the vegetable you want to grow listed in the table. See the spacing they recommend, use the larger number. Get your ruler out and some little sticks (pencils?) and go sit with your pots and stick the sticks to mark where you would put plants and see how many you can fit in a pot, measuring between them to be sure. What about the edges of the pot? Treat them like another plant and leave the same space between the sticks and the edges as between the sticks, though you can put the plants a LITTLE bit closer to the edges than to each other. Leave the sticks there so you know where to put your plants when the time comes, heck even lable the pot for which plant it is you want in that pot. Voila, square foot gardening with no math.

Cheers!

sunnibel is right, I misspoke. For some reason I was thinking you already had the surface area and wanted to add in depth.

Although sq ft gardening is based on area, volume matters. In the sq ft garden, you basically have a low, bottomless container, so root growth in not limited. I have found that even though some things grow better for me in containers - like peppers - I need to use large containers. 30 gallons or more in order to ensure that they don't dry out too fast.

I could not see that you were limited to a balcony, so if weight doesn't matter, you might try to build your own containers. I just use scrap building lumber to make attractive containers that are as large as I want them. Of course, they are where they are. As large and heavy as I make them, moving them without emptying them really is not an option.

And yes, I can relate to the other comments regarding the container garden forum. It's been a long time since I have bothered looking in there, but I think of the forum as The Cult of Al.

Well, as for your math problems, you'll probably do better if you forget all of the terms that have been tosses at you ("area") and just think in terms of dimensions (visualize it). You have two dimensional issues (length and width without regards to depth - think of a sheet of paper) and you have three dimensional issues (length, width, and depth - think of a cardboard box). Most of the problems you're looking at (how close to plant different items) are largely two dimensional issues - you don't care about depth because the container either is or isn't deep enough for what your planting. Regardless of whether you're dealing with a two dimensional issue or a three dimensional issue, you can always find the total space occupied by multiplying the dimensions involved (2D is Width X Length. 3D is Width X Length X Depth)

To address some your questions though there are a few things you need to realize about gardening (I'll probably get a lot of objections at this point, but such is life):

1. A plant doesn't care how much space it has to grow. It cares if it has the inputs it needs (water, light, nutrients) and enough physical space to fit what it's growing in (you can't make two carrots occupy the exact same physical space - they're side by side or some other setup. You can't violate the laws of the universe...)

2. Because we don't know exactly (we know roughly) what any given plant needs, and given the logistics and expenses involved, it's pretty much impossible to grow plants side by side smashed into each other with no space in between and still provide for their needs. This given, there has to be some space involved. How much space becomes a trade-off which is dependent upon your growing environment. The better you provide for your plants needs, the closer you can plant them. Given that you're not going to do it perfectly (or even close in most cases) - none of us do - there will have to be a reasonable amount of space. If you space your plants somewhat too close together, this means they're going to have less of the things they need (light, carbon dioxide, oxygen, nitrogen, etc.) and they won't produce as well. On the other hand, if you space them too far apart, you reach a spacing where adding additional space does not benefit the plant any further and production does not improve.

3. Square foot gardening (which isn't a good fit for container gardening, but there are some good things we can learn from it) hinges on the principle of production per space. It tries to maximize NOT YOUR PRODUCTION PER PLANT, but your production per given amount of space to grow in. If you space wider than typical square foot gardening recommendations, you can get better production per plant, but probably won't have as good of production per given area of space. So with square foot gardening principles, your accepting less production per plant so you can cram them in closer together and get a higher production per given area of space.

That said, in the guidelines for square foot gardening, there's also an assumption made about the space requirements for a given category of plant. As any of us know that plant heirlooms, there is an infinite variety within any particular vegetable you care to grow - tomatoes, peppers, eggplant, you name it. Some of these varieties have very different space requirements. I've grown some tomatoes where the plant was so small and compact I could comfortably fit about 4 plants in a square foot. I've had other monster tomato plants that would have been more at home in a 2x2ft square - but only if I was growing vertically and let it go about 7ft straight up.

4. At the end of the day, you have to know the plant you're planting to have a real good idea about how much space it's going to need. How good you intend to take care of it will be important to how close you can space them.

5. Realize, that other than your root crops, many of your vegetables do most of their "underground work" in the top 6-8 inches of space. A foot depth is plenty for just about everything even including a decent number of root crops. Anything beyond a foot is usually a waste representing excess unused soil in the bottom of the container. If you find yourself with extra deep containers - strongly consider cutting some holes in the sides of the containers and planting something in the sides of the containers. Take a look at some of the strawberry planters available and you'll get the idea.

6. Don't forget about light. For your fruit producing vegetables (and really the others too), there's going to be a direct (very direct, very obvious) correlation between the amount of light your plants get and the amount of produce they provide. If you don't provide enough light, it's possible you'll have what looks like a very nice, very healthy, very big plant that doesn't produce a single fruit. Not one. I speak from experience. The first house I started gardening in as an adult looked like it had been dropped in the middle of a forest with no thought for a clearing. The only "clearing" I had was the road out front, so any planting I did I had to do on the front of my property. I had more moss than grass in my yard. I had a fenceline that went out to the front of the house that I grew tomatoes along. The closer you got to the road, the more light they received and the more tomatoes they produced. About 10 ft back from the front of that fence I had some really nice looking plants, but no tomatoes. I've had other examples of this as well. Proper sunlight is essential to crop production. Pay attention not only to your container placement in relation to the sun, but also in relation to the crop(s) in them - you don't want some of your crops shading the others enough they can't get proper sunlight.

7. You can grow crops of any size in containers - just be prepared to deal with the results. If it's a big melon, it's going to vine out over the sides and take up some space unless you arrange for it to go vertical. Big crops are also typically going to require more inputs, so make sure you're keeping enough of what it needs in that container (starting with water). If you're going to grow very high vertically, and you're outside, wind may be an issue. Be prepared to tie down, stake, etc. that container in some way so that it doesn't tip over when it has your seven foot tomato hanging out of the top (voice of experience).

Some spacing I've done when container gardening which may be of value to you:

typical 5 gallon bucket - 1 or 2 peppers.

Square pot roughly 1.5x1.5ftx1.5ft - I put one large vining tomato in the center and one pepper in each corner. This is a bit tricky and crowded, but it can be done successfully.

Shallow flower planters roughly 3ft long by 0.5ft wide by 0.5ft deep - 3 to 4 peppers, a row of strawberries, or 3 really small, compact tomatoes.

Hope this helps.