University of Maryland Extension

How do I keep out deer?

UMD Extension has an excellent guide to "Managing Deer Damage in Maryland," by Jonathan Kays. It includes a particularly helpful section on different fence designs. If possible, build your deer exclusion system BEFORE planting. Once deer know that something delicious is behind a fence, they become much more determined to get past that fence.

When building fencing, also take local zoning rules into account.
Baltimore City's zoning and building codes are online here: https://legislativereference.baltimorecity.gov/city-codes#search  
The section on fencing rules is in this document called "BUILDING, FIRE, AND RELATED CODES," under "SECTION 3114 FENCES," on page 103 (p. 129 of the file).
For other urban parts of Maryland, here are links to your local zoning authority: https://extension.umd.edu/learn/land-use-regulations-and-zoning 

 
Maintained by the IET Department of the College of Agriculture and Natural Resources. © 2020. Web Accessibility

University programs, activities, and facilities are available to all without regard to race, color, sex, gender identity or expression, sexual orientation, marital status, age, national origin, political affiliation, physical or mental disability, religion, protected veteran status, genetic information, personal appearance, or any other legally protected class. If you need a reasonable accommodation to participate in any event or activity, please contact your local University of Maryland Extension Office.