Large containers allow you to grow vegetables even if you don't have a good area for a garden. Tubs work well for vegetables because they can hold many gallons of soil, they are compact, and they can even be portable. You can choose from large plastic totes or half wine barrels to unusual containers such as wheelbarrows and bathtubs. Just make sure your tub has at least one drainage hole or the roots of your veggies will rot and the plants will drown.
Drill several evenly spaced drainage holes in the bottom of your tub if it doesn't have any. Use a large drill bit, at least 3/8 of an inch in size. Then place your tub or other container in an area that receives as much full sun as possible. Prop it on top of three or four bricks to improve drainage.
Fill your tub with either a good all-purpose potting soil, or combine topsoil with compost and other organic materials such as dried leaves or grass clippings. You can use up to 50 percent compost and other amendments---the richer the soil, the better.
Water the soil well by running a hose at a slow drip for about one hour, or until water flows out the drainage hole(s).
Dig small planting holes for your vegetables that are large enough for their root systems. Depending on the size of your tub, you can plant several varieties of vegetables in each tub. Just leave about 6 inches of space between them. Water well, and then water once a week, or whenever the soil at a 2-inch depth feels dry to the touch. Container-grown vegetables might need more frequent watering than those in the ground---but don't overwater.
Fertilize your vegetables once a month with a balanced plant food, such as one having an N-P-K ratio of 10-10-10. You can also spread a layer of compost on top of the soil as mulch---this will give your plants continuous nourishment every time you water and will also help keep weeds away.