Few endangered plant species are available for purchase or planting, in part because wild populations are too sensitive to support seed collection that would reduce their ability to reproduce. The Wildlife and Heritage Service within the MD Department of Natural Resources is the agency that identifies, protects, and manages rare, threatened, and endangered plants ("RTE") and their plant communities in Maryland. They list a contact person for the program on the DNR website (see link). There are legal prohibitions pertaining to RTE plant species, though enforcement may be limited since clearly some of the species on the threatened plant list we link to are widely sold at nurseries. You would have to get more feedback about this issue from the DNR directly. Conservation biologists tend to not support growing RTE plants outside of their current range so genes from one population don't "contaminate" the gene pool from another, in case that makes their seedlings less able to survive the unique challenges of where they are still growing.

We don't know what you mean by "self sustaining greenhouse"...can you elaborate? Plants grown in greenhouses tend to be tropical species, or the greenhouse is only used for providing minimal protection in winter for hardy plants grown in containers, where the roots are more vulnerable to freeze damage. While UMD Extension doesn't have much information about home greenhouse design and construction, we can share some web resources that might be of interest:

• The Hobby Greenhouse -- Oklahoma State University
• Hobby Greenhouses -- University of Georgia
• Hobby Greenhouse Design Notes -- University of Oregon

Endangered species rely on the community of plants and animals that they interact with, and saving one species from that environment won't conserve much without the entire ecosystem being protected as a unit. Therefore, endangered insects can't really be taken out of their ecosystem to another area for preservation (zoo animal breeding programs aside). Instead, it's best to increase protections for natural areas that still harbor any RTE species.

It might be easier and more rewarding to use your property to cultivate native plants (not rare species, just those that are well-suited to your site conditions), eliminate pesticide use, and grow a diverse range (where practical) of plant species so they can in turn support as many insects, birds, and other animals as possible. If neighbors can be convinced, especially through demonstration, that native plant gardening can be attractive and functional, then the more properties in the area that convert traditional yard spaces like lawn and over-planted non-native species (including invasive species) to a mix of site-appropriate natives, the greater the ecosystem benefit can be. Perhaps you can encourage local businesses or public spaces (libraries or schools, for example) to install pollinator gardens or other native plant-focused plantings to help others see the value of preserving and using native plants in our landscapes. We agree that continued habitat loss is frustrating and demoralizing, though perhaps getting local officials to recognize the value of land preservation and "smart" development will reduce those impacts going forward.

Miri