We don't have much information on Pecan growing in Maryland, either commercially or at home. Their natural range (lime-green counties on the linked map) does extend relatively far north in latitude, but winter hardiness might still be an issue here, especially if they are grafted, as discussed in Oklahoma State's Pecan Varieties for Oklahoma article. Even though OK is further south than MD, they have essentially the same spread of USDA cold hardiness zones across the state as we do. They also provide a bit of information on variety pros and cons as it pertains to nut quality and overall tree disease susceptibility.

Attention has to be paid to choosing a compatible pollinator when growing pecans, as a single tree won't self-pollinate and some trees shed pollen earlier or later in the flowering season than others. (Either male flowers on a tree open and become fertile first, then the female, or vice versa.) Since Pecans are large trees compared to other tree types that produce a crop (fruits, mostly), this is a notable space requirement to consider.

We don't have a local recommended variety list, but you can explore other Extension web pages that discuss pecan cultivation, since they are a more significant crop in other areas. The resources below all provide useful information, even if a bit of it is specific to their local conditions:

• Washington State University – Growing Pecans in the Home Garden
• Kansas State University – Growing Pecans in Kansas
• Oklahoma State – Managing Pecans in the Home Landscape
• NC State – Growing Pecans in North Carolina
• Clemson University – Pecan Diseases

Miri