It depends on the layout. By field edge I assume you mean the edge of a woods. Switch will grow at the edge of a woods, but it won't be as thick and nice due to tree roots sucking away moisture and nutrients. Also, sunlight is a factor. The north edge of a woods is notorious for being even tougher growing conditions, because of reduced sunlight.
Shrubs that fit the soil type and available sunlight are the best bet for right next to the timber. A hearty shrub in my area for those conditions is Arrowwood Viburnum. It makes great edge screening, and deer browse it really well. Rough leaf dogwood and some of the other bushy dogwoods have also done well for me - however, it appears that I'm too far south for Red Osier Dogwood. Any space left open where I live will soon fill up with wild blackberry. Some of that is okay, but it can take over. Best wishes.