Question
Hi Mike,
 First off i would like to say thanks for your time. My first question is what defines a vegetable and a fruit? Also i live in Pennsylvania and was wondering if it possible to grow cucumbers and/or potatoes where i live (20 minutes north of Philadelphia) and how? Thanks a bundle i hope your willing to answer any more questions i have.
  -Barrett  

Answer
Barrett, believe it or not, a fruit and vegetable are distinguished only by how it is defined by the U.S. government.  For instance, a tomato is by definition a fruit, yet classified as a vegetable.  

A fruit is defined by any fleshy growth on either a bush or tree that covers a seed or group of seeds.  A vegetable is defined more by its leafy growth.  Therefore, botanically a tomato is a fruit, but horticulturally it is classified as a vegetable.  This is due to it being an annual and grown on a non-woody plant.  Fruits on the other hand are perennials grown only on woody plants or vines.

To complicate matters even further, the Supreme Court actually made a ruling in the late 1800's to classify certain plants as vegetables.  These included fleshy edible plants such as tomatoes, peppers, and eggplant.  The reason they got involved was to protect U.S. farmers from having to compete with imports classified as fruits that were not subject to taxes.  Imported vegetables were taxable which made it more feasible for consumers to purchase U.S. bred vegetables.

In response to your second question, you can grow both potatoes and cucumbers in your area.  I live in Ohio where our weather is not much different than yours, and both plants grow great.  

You want to plant these after the last expected frost date, which is normally around May 15th.  Cucumbers take 50 days to harvest; potatoes take 75 to 90 days depending on the variety.  Just be sure to grow these and all vegetables in a well amended soil that includes compost, aged manure, shredded leaves, and peat moss.  These organic supplements add nutrients to the soil, protect against insects and disease, and improve drainage in the soil.

I hope this helps.  Enjoy the rest of the summer.

Regards,

Mike