Don't mix the peppers (or even plant close together) & leave lots of room for the onions to grow under the soil. Tomatoes are best grown in a moisture controlled environment (whether it be the soil mix you use or an environment of your own). Everything else you need to know can be found here on GardenWeb. =)

I do a LOT of container gardening. My best rule of thumb is this: Select the container which you think you will use to grown your tomato, pepper or whatever, etc in........then put it aside and use one that is at least one size larger. The most common error people tend to make is using containers that are too small. It really doesn't make a huge difference what you use, as long as it is big enough and it has lots of drainage. I use everything from home-made planter boxes to giant plastic storage tubs. Basically, the plant needs to be fooled into thinking it is growing in the ground. You'll be happy with the big container when you realize you do not have to water it as often as the small ones, and that, as your plants become large, it does not tip over.

Here is my advice. I was a FOOL when I first started into the container gardens. Finally figured out if you go to the nursery you can buy those black containers (used) for cheap. Not telling you what I spent on terracotta-looking (plastic) pots at lowes. It gets expensive fast when you start out, cut corners where you can and save the money for GOOD soil.

Tomatoes : Least 5 gallon container (true 5 gallons) - but depends on variety. Indeterminates can get big, 10 gallon might be better.

Patio tomatos do great in 5 galls, I had them in 3.5 gals.

Sweet/hot peppers : 3.5 gallon take a while to get big.

Yellow/red onions : do not know

lettuce: I used small 3.5 gallons here to.

cucumbers: 5 gallon

sweet corn : do not know

Asrtd Herbs : Herbs are fine in 3.5 gallons as well. Even
smaller. Little 10 inch pots are fine.

Got to watch the fast growers like tomato. In 2 months they will be root bound. They are hard to switch pots after that.

Keep the water off the leaves. Use a dripping system like Mister Landscape.

For year one, just use Miracle Grow. Your just starting and got to feel your way to. The best way I say, get miracle grow, the pots and dripping system. Do not do to much math the first year, let nature go. They will grow and you can worry about doing it better in year two. Your not going to beat the pro's your first year out so do not bother trying. You will be setup for disappointment.

This is my third year in, and I have a good old time and allot of knowledgeable here are glad to help (and helped me allot).

Start their and have fun!

I highly recommend going to grocery stores and getting 5 gallon buckets from the bakery. Usually they will give them to you for free and you just have to clean them. Cleaning takes a bit of time and lots of dish soap, but you end up with large free pots.

You can also go to the dollar store. Sometimes they have real pots, but you can also try buckets or plastic dishpans.

Alice

Is there an easy formula to figure out how many gallons a container is in size? height [inches or centimeters] x diameter [inches or centimeters]= [ ]gallons?

Thanks Fern

Yes, there is, Fernsk, unfortunately they often don't apply because most containers don't conform to regular geometric shapes.

There are 7.5 gallons of soil/mix in 1 cubic foot.

So, how many gallons/cubic feet does an 18" container hold? No way to know because 18" only tells us the diameter of the container. Is it square or rectangular or is it a sphere? Is it tapered or straight? How tall is it?

You get the idea.

For square/rectangular containers without a taper use this:
L*W*H / 1728 = Volume (cu ft)
Replace 1728 with 231 to get gallons

For round containers without a taper use this:
R^2 * Pi * H / 1728 = Volume (cu ft)
Again, replace 1728 with 231 to get gallons instead of cubic feet.

If your containers have a taper you kind of need to figure an average to use.

I am new to vegetable gardening in containers. But I do know that it does not make sense to try to grow corn in anything but a really huge garden. For most varieties one huge corn plant only produces one ear of corn. It takes a lot of space to have even one short corn harvest.

Climbing to the top of Mt. Everest makes no sense either ..... Some do it simply for the challenge. ;o)

Al

Hi JAG,
R^2 mentioned above has me a bit confused.
? Radius with what factor application is " ^2 " ?

Radius squared. In other words the radius multiplied by the radius.

Take a typical 5 gallon bucket with a 12" diameter. The radius is half the diameter.

So, R^2 * Pi * H / 1728 = Volume (cu ft)

Let's break it down

Lets assume our container is 12" in diameter and 12" deep.

The container is R^2 (6x6=36) * Pi (3.14) * 12 (height)=1,356

If we were to divide by 1728 we would see it is less than a cubic foot. It is about 3/4th a cubic foot.

If we divide 1,356 by 231 we get: 5.9 gallons

Okay since I've just realized how mathematically challenged I am, I figured out that you gave me an easy answer: if 1 cubic foot of soil equals 7.5 gallons and alot of potting soils come in 1 cubic foot bags - ta da I'll just note how much of the soil fills each of my pots. I've only got 4 sizes so that will be easy. Thanks

Fernsk

I usually just buy the 5gal home depot or lowes buckets to use as containers. They are usually on sale for $2-3.

Firehouse subs offers their used 5 gallon pickle buckets for a $2.00 donation that goes 100% to firefighters. Its easy to get as many as you want at any time (I got 30) and its for a better cause than Home Depot, not that I'm not at the HD at least twice a weekend.... :o)

the HD buckets are $5 where I am, and Walmart is $4.

at the grocery store bakery they are FREE!

To figure out volume of a slanted round pot, I am doing:

measure how wide the top is. and how wide the bottom

average radius = (top width + bottom width) / 4;

measure the bottom to top of the container. Not along the slant, but straight up. Subtract 1 inch because you probably won't fill it to the top. Or you could leave the inch in if you think your soil will compact. Use this for the height.

So your cubic inches would be 3.14 x (average radius) x (average radius) x height.

Then convert to gallons by dividing with the 231 cubic inches listed above.

Volume = 2 Pi R squared x H.

Alice