Draw an object-oriented data-model

Draw an object-oriented data-model, with all appropriate notation, to represent the following situation. In a particular region there are a number of gardens. One attribute of GARDEN is its LOCATION. A method must be included in GARDEN to calculate its acreage (CalculateAcreage). Each garden is a collection (or assembly) of plants. Attributes of PLANT include NAME and DATE PLANTED. There must be a method to calculate the age of a plant (CalculateAge). At the present time, there are two subtypes of plants: FLOWER, and VEGETABLE. This list is not exhaustive, since other subtypes may be added at a later date. COLOR is an attribute of FLOWER, while YIELD is an attribute of VEGETABLE. There are two (and only two) subtypes of FLOWER: ANNUAL and PERENNIAL. DATE TRANSPLANTED is an attribute of PERENNIAL.