Dwarf varieties usually require less soil than full sized plants. A full sized tomato plant needs at least a five gallon pot, where a dwarf tomato plant can grow in a 3 gallon pot. Cages are required for most larger and vining type vegetables. Peppers, bush cucumbers, dwarf tomatoes, peas, broccoli, beans and carrots can all be grown in 3 gallon pots. Leafy vegetables can be grown in window boxes, or 1 gallon pots.

 For root vegetables, deeper pots are better than shallow pots. I have successfully grown Red Pontiac potatoes in a five gallon bucket. Don't use regular garden soil in your containers, this can become compact, instead use a soilless mix. Container gardens need more fertilizer than in the garden, because the roots are contained to a limited area. . I recommend using a balanced time release fertilizer mixed in your soil such as Osmocote and fertilizing with a liquid fertilizer weekly after your plant is established.