Unless you have an outdoor table with built-in umbrella support, you are going to need a base to prevent damaging your lawn and to stabilize your umbrella. The minimum safe weight for an umbrella base is 50 lbs.; however, the larger the umbrella, the heavier the base needs to be.
Multiply the diameter of the umbrella by 10 to find the ideal base weight. For example, a 10-foot umbrella needs a base that weighs 100 lbs.