The best time to be there is in spring and in the late summer. In Spring you will find loads of peachtrees and appletress or cherrytrees in full blossom. In late summer - e.g. in August you can enjoy one of the many folk festivals around wine. All of the winemakers are usually to be found on these folk festivals and you can try all that tasty stuff from around the area.
Heidelberg is not too far and a trip to the famous Heidelberg castle is easy and quick to make from here. Also quite close is the Frankfurt airport. As Frankfurt is the second largest airport in Europe, you will find direct flights from all big cities around Europe and elsewhere.
If you want to taste something from around the area, go for "Fleischwurst" and "Apfelwein". I cannot show you the Fleischwurst (it is sort of a sausage being heated up) because where I live right now it is impossible to buy it. There are some shops offering "Fleischwurst" all around Germany, but the hessian one is different and cannot be compared to what you can buy elsewhere. So try it only if you are in Hessia - nowhere else.
The Apfelwein (wine made of apples) is something that needs getting used to it. I never will, because the taste is extremely sour and dry. But give it a try and see for yourself. It's typical hessian. If you do not like it; you will certainly find some regular wine made from local winemakers. And, oh .... do not try to get a Weisswurst in Hessia.