As for giant size containers for tomatoes: In 30 years of off-and-on container growing (I prefer square footing in dirt if I can) I've never resorted to such huge containers and my tomatoes have always yielded more than I could use. Possibly putting them in extra-large containers like that would have yielded even more, but when you already have an excess, a larger excess isn't necessary. I usually only grow one of each type of tomato I want when growing in containers. I grow only determinate types for the past 20 years; before that I most often planted indeterminate types and have found them not to be worth the trouble. Again - when you already get more than you can use, an excess of excess is really not required. If you're growing indeterminate types then a larger container like that would be useful just from the point of view of not wanting your 8' tall vines to tip the container over. But it is not NECESSARY to growing plenty of good tomatoes. as for 4' long tomato roots - possibly, if you count vertical growth. But I personally have not ever had a tomato put down any significant amount of roots past about 18" - that could be deeper in sandy soil, but not the clay loams I have typically gardened in. And yes, I HAVE dug them up to check root depth. I used to be a fan of deep planting of new tomato plants. I would dig, double dig, "work in organic matter". (NOTE: Don't do that. Let the worms do it for you. Encourage worms to work for you by planting cover crops and deep mulching when cropping). Then when the bed was ready I would dig a hole deep enough to bury the entire plant except for the top couple of pairs of leaves, pinch off all leaves and branches on the way up, and bury the plant to its eyeballs. The plants always seemed to grow just fine, but one day I came across an article that stated that planting tomatoes this way wasn't very useful because anything below about 10" to 12" just ended up never putting out any roots and sort of amputates itself off, and it's only the upper part of the stem that roots out. This doesn't really HARM the plant generally, but it doesn't exactly speed the development. So the proposed method of planting instead is trench planting, fairly shallow comparatively. Humph humph, sez I, generations of tomato-planting lore can't be so far wrong! So the next year I planted half my tomatoes the "traditional" way (at least for my family) and half the doubtless silly and unhelpful new-fangled way. And sure enough, the (relatively shallow) trench-planted tomatoes were sturdier, bloomed and fruited earlier, had fewer of the few problems I typically ever have with tomatoes, handled both torrential downpours and dry spells better, and eventually yielded more. When I dug up the plants at the end of the year, sure enough, those traditional, deep-planted tomatoes had only rooted out of the upper 8" or so of the stem (the rest being the existing root ball). In many cases the perfectly preserved lower parts of the stem, including the original peat pots, were still to be found, like archaeological evidence in deeper layers. When I say "fairly shallow" I mean that I never dig down more than 10" to 12" and plant the plant at an angle or on its side in the trench so that just the top 2 leaves are showing. I support the stem with dirt (backfill under the stem when it's at an angle) and bury the entire stem, but no part of that stem is any deeper than about 8" tops. (remember not to count the rootball, just the length of the stem, which is usually 6" to 8" by the time the ground where I lived was warm enough to put tomatoes out). The truth is that the vast majority of root growth for a tomato in the ground (not in sandy soil but in moderately good clay loam) is in the top 12" of the soil. Tomatoes growing naturally (eg in the wild) sprawl, and root along their stems - eg ROOT SHALLOWLY. You'd be hard pressed to find roots below 18" to 24", and not many at that depth. (Again, ignoring sandy soils, which I have never grown in). Now container growing NOT EQUAL growing in the ground. In the super light container mix that one should be using in a container roots undoubtedly do penetrate deeper. But tomato plants do not need 4' of soil depth for proper root growth. They are a relatively shallowly rooted plant. Now clovers, by comparison, are a different matter. A well established stand of some kinds of clover can have roots extending 5' or even more - at least one variety has had measured root length of 20'. Keep in mind though that that's total root length, a lot of which is horizontal - so 5' long roots do not necessarily extend 5' DEEP, and 20' roots CERTAINLY do not. Clovers are, however, a very deeply rooted plant. That's why (when I was still dirt-gardening) I liked to use clover as a cover crop when preparing a new bed - first cover with cardboard to kill turf (weighted so it won't blow away of course) from fall into the next spring. Then dig out the dead turf and compost it, do just enough tilling to break up the top 8" or so of soil, broadcast seed buckwheat, mow, broadcast seed again, usually I could manage 3 buckwheat crops a season. The following year till again (now much easier due to the organic matter from the buckwheat stems and roots and incursions of earth worms) and sow a good clover. Let that go at least a year, two if I could manage it, mowing I think in the early spring (it depended on what clover I was using). One more visit with the tiller and I had a great garden bed. I would switch between 2 or at most four plots (depending on where I was at the time and how much space I had), using cover crops on the fallow bed(s). Anyway. I don't dirt garden anymore, I am just not physically able and my son has zero interest. So it's pretty much containers all the way for me these days. Though when we're no longer in rental properties I would very much like to have a small square foot garden for things like icebox watermelon and other space-hungry things that just don't do well in containers. Garlic, some perennial herbs. Anyway anyway. I don't think there is anything WRONG with planting in such large containers, but at my age, at my size (I used to be ALMOST 5' 2" and have definitely reached that point in my life where shrinking begins, if it isn't already well advanced, LOL!) and in my physical condition - those containers are far to large for me to manage. I get more tomatoes than I can handle from much smaller, easier to manage containers. I don't grow indeterminate varieties so I don't need the extra anchoring effect from such a large container. And I won't throw away potting mix after one use, won't use it unsterilized more than one season, and can't handle the weight and quantity just one of those trash cans holds. It isn't NECESSARY to use such large containers. If you want to and can manage it, or if you are determined to grow an indeterminate variety in a container, then more power to you. It sure isn't likely to HURT anything (excluding possibly your back, LOL!). But it isn't NECESSARY. People grow good tomatoes in 5 gallon buckets. Personally I think that's too small, I think the earthbox type containers are too small as well, but lots of people grow good tomatoes in pretty small containers. I like a container that's at least 16" deep and at least that high and wide. That has been plenty big for the non-determinate tomatoes I most frequently grow. Now if you're after beefsteaks - you can grow in that size container but you PROBABLY won't get optimal size fruit. Most of the better beefsteaks (IMHO) are indeterminate varieties (in fact probably ALL of them are) so that type of tomato would benefit from a larger container. I don't think there's really anything wrong with giant sized containers, I just know they aren't necessary. Indeterminate or large-fruited tomatoes would benefit from a larger container though I can't say you would have to go THAT large - but they are certainly cheap, so why not, if you can physically handle a container that size and tomato vines 10' up in the air. But don't get scared and think you HAVE to grow in containers that big. Any indeterminate variety, and many determinate varieties as well for that matter (if you don't mind regular pruning and redirecting of vines) can be grown in a MUCH smaller container. Actually, taking one of those trash can containers and cutting the top off (so what's left is 16" to 18" deep) wouldn't be a bad idea either, since you can usually find those size cans for around $8 to $10. That would certainly be easier to handle. I may have to try that after we get moved. It'd probably make an excellent potato "bucket" too.

I found that my 5-1-1 pots where staying entirely too wet; and that was only with rainwater. Of course, I don't have full sun either. I went through the same head spinning thing reading the soil/water dissertations - and then hit a brick wall stalemate finding the large many cubic feet bags of perlite. At any rate, I dumped mine out; added same coarse sand, grit and perlite; mixed it up; but it back in and replanted. I figure if it doesn't hold water well come heat time I'll either re-mix them or most probably add about 4" of mulch. I've also found using a spritz bottle on seedlings to be better than a watering can this time of year. Well, I can't actually carry a watering can; but I'm sure you get the idea. Now I just need more seedlings to grow up and get ready to move into toddler beds. ~dianne

In my experience, people tend to use the term "potting soil" as a generic for the stuff you buy in bags at the store (Miracle Grow, etc.), but if you read the label on those bags, a product that is intended for containers is actually called "potting mix". There is no "soil" or "dirt" in them. Thus experienced gardeners on this forum will emphasize that you want a soil-less mix for containers. True "soil" is too heavy for containers and will not drain properly. So what is in them, if not soil? Typically a mix of peat, shredded bark, sand, perlite, and/or compost. They may or may not include added fertilizers. Many people just buy the mix in bags, especially when they are starting out and if they don't have to fill a large number of pots. Others will buy the components and mix up their own, both to save money and control what goes into it. It depends on what quantities you need, how much money you have to spend, how much room you have to mix them together, and how much storage space you have. If you visit the Container Gardening forum here on GW, you will finds lots of threads that talk about various recipes for mixing your own. I'm not sure what products are available in Tokyo, but I think the research will help you evaluate the products you can find locally and decide which direction to go in. Good luck! Here is a link that might be useful: Container Gardening forum

There are many discussions of this question over on the Growing Tomatoes forum here and the search tool will pull up many more from the Container Gardening forum and several other local forums. Container Gardening has good discussions on what to fill them with. As a very general recommendation 5 gallons is the very bare minimum recommended and then only for the smaller varieties, the dwarf and compact determinate varieties. And even then there are problems keeping them fed and watered well enough to produce well. So as Zesty said above, the bigger the better when it comes to containers. Personally I use a few 10 gallon ones (have 6 of them for determinate tomatoes), several 15 gallon (have 12 of them for normal indeterminate tomatoes), and for the really big plants like Sun Gold and others 25 gallon (50 gallon drums cut in half). Dave