Ask Mr. Smarty Plants

The first problem with your request is the "deer-resistant" stipulation. We have a list of deer-resistant plants; please read this disclaimer paragraph from the top of the list:

"Deer Resistant Species

Few plants are completely deer resistant. Several factors influence deer browsing including the density of the deer population, environmental conditions such as drought, and plant palatability. Deer tend to avoid plants with aromatic foliage, tough leathery and/or hairy or prickly leaves or plants with milky latex or sap. Try using some of the plants listed here to minimize deer damage to your landscape."

Further complicating this problem is the fact that there are only 346 plants on that list, and that constitutes the known native deer-resistant plants for North America, including Canada but not including Mexico. By the time we sort that list down to Pennsylvania,  there may be very few choices. Adding "evergreen" is another problem, as well as poor drainage and part shade. First, we will go to our list of Deer Resistant Species and then, using the Sidebar on the right-hand side of that page, we will select on Pennsylvania for the state, "shrubs" for Habit, "evergreen" for Leaf Retention and  6 to 12 ft. for the mature height. The search, using the same specifications can be un for for "tree" as the habit. Caution: You will need to read the whole webpage on each plant; some of the indicators will be "Highly Resistant" under deer resistance, some will only be "Moderately Resistant." Our examples are all Highly Resistant. We will also estabish that each plant will grow in Montgomery and Delaware Counties in the southeastern portions of Pennsylvania.

Before we even talk about specific plants, you need to deal with your poor drainage. Down here in Central Texas we have a lot of clay soils which do not drain well but we are also very drought-stricken so it isn't always too much of a problem, but a problem, nevertheless. From Better Homes and Gardens, here is an article on Improving Poor Drainage. We would suggest you address that situation before you start putting in plants. We will hope we can find enough shade tolerant plants that will live there.

Uh, oh, nothing at all. There were three that fit all the specifications but evergreen. They are:

Amorpha fruticosa (Indigo bush)

Cephalanthus occidentalis (Common buttonbush)

Rhus aromatica (Fragrant sumac)

Next, try going to our Native Plant Database. Using the Combination Search midway down that page, search on Pennsylvania, shrub, shade and part shade, wet soil and 6 to 12 ft. in height. We have eliminated the "evergreen" and the "deer resistant," but you can still read each webpage to find out the various characteristics of that particular plant. Again, these will be plants that will grow natively in Pennysylvania.

Okay, that gave us 41 results, including the 3 above. Now you can go through that list and see what comes closest. If ""evergreen" is most important to you, try running the list with that requirement but eliminate "deer resistant" by not using the Deer Resistance List. Now that you know how to use our Native Plant Database, you know how to prioritize what you want. Usually there are pictures on each plant webpage and clicking on a picture will give you an enlargement.