My hands are sore and swollen from working in the garden. Are there any supplements or food that can help?

Rest. You could have over worked your hands causing them to be sore and swollen. Rest can help and possibly otc anti-inflammatory medications. If this does not help you may need to go to the doctors to be evaluated and diagnosed.
Glucosamine/fish oil. Natural antiinflammatories help the whole body and fish oil is the best to use. Also look at foods with turmeric. Glucosamine is a good supplement to use for joint health but give it a couple of weeks of use before you look to notice a response.