billt, for a barrel cut in half, here is an old Iredell County, NC trick from an old farmer, take a 20oz empty plastic soda/water bottle. Punch small holes in the bottom third of the bottle. Like 6d nails, 8d.....kinda small. Bury the bottle up to the neck with just the top inch and a half showing.
Good ol Black Cow, Black Chicken if you can find it, mixed with any good potting soil, will do well. twice a month, take the liquid tomato food mixture, and pour it in the top of the partially buried bottle. The nutrients get directly to root level and is like an I.V. of the good stuff.
For AZ, the previous posts about some type of cover are warranted. An old piece of screen, like for patios, on a 4 point cover, just to break the sun's intensity off a bit. of broken sun, semi covered patio, etc,...
Also get the suckers. They are sprouts that appear at the "V" of the stems, kinda like a new growth out of the armpit of the branches.... just pluck/ pinch them off.
Make sure the cut barrel is well draining. Tomatoes love water, but hate long soaked roots, which will lead to root rot, and a weak plant. Gentle misting of the leaves with a couple drops of dish detergent or cayenne pepper in a little spray bottle will keep pests away.
I love my .45 caliber Beefsteaks, and Heirlooms , every year. It's not anything fancy just homegrown "mater's"....

Solus, for hard sandy soil, find some chicken crap, or manure, from a farmer, or mix topsoil and the native soil in a wheelbarrow, pick the spot, and plant with the tweaked soil, Garden Lime, in modest amounts help hard soils, and partial shady areas, will help keep the soil from drying to rock hard consistency.
Just my .02 cents,....my wife is actually the mater junkie,...I just reap the rewards of making her smile when I come in with a big.............
tomato
