The concept of the 3 sister's garden has been around for hundreds of years. It is a great idea that can be modernized to suit the needs of today's busy gardener. The traditional 3 sister's garden has corn, peas and squash planted in a half barrel. I say its time for an overhaul that is long past due.
To get started you will need to have a base. Choose a larger plant such as a tomato or pepper plant and two medium plants such as squash, watermelon or strawberry. Find 2 smaller plants such as Marigolds for color. You can choose a full size larger plant, but when you choose the two medium plants try to find varieties that are pot friendly such as Sugar Baby watermelon or Minnesota Midget. Mix and match the smaller varieties. For this example I am going to use a Sugar Sweet Cherry tomato, an Ozark Beauty strawberry, a Sugar Baby watermelon and 2 Marigolds.
Buy a 5 gallon bucket from you local home improvement store and drill 5 quarter inch holes in the bottom. Cover the holes with mesh to prevent soil from seeping out. Fill the bucket with potting soil leaving about 2 inches of space. Plant your seeds or plants according to their directions with the tomato in the center a strawberry on one side and the melon on the opposite side. In between plant you're Marigolds. So when you're done you should see a tomato in the center ringed by the other plants. This gives plenty of room for the tomato to get water and nutrients.
Once the plants have taken root place 1 inch of mulch inside the container to help keep the water from evaporating. Water the plants in either early morning or evening. Keep the bucket on a hard surface such as a deck or patio. This will allow proper drainage for the plants. Soon you will be enjoying up to 3 different fruits or veggies.
Please experiment and see what works well for you. I recommend trying one or two buckets to start each with different varieties. These mini gardens are perfect for decoration, saving money and space.