Abstract: Restoration efforts are attempts at creating and assembling local communities that have vanished. Recent studies have shown the importance of using local ecotypes of species as building blocks in these assemblies and the need for including information on genotypic differentiation has been stressed. Large portions of brackish east coast marshlands have been invaded by non-native, European genotypes of the common reed, Phragmites australis. As a result, only a small fraction of the NJ Hackensack Meadowlands is now dominated by native marsh species and only isolated patches of Spartina patens remain. As these patches vary in size and seem to resist encroachment by Phragmites differentially, we are investigating (a) whether larger patches are able to resist invasion more than smaller patches and (b) whether large-patch clones are better suited for restoration efforts. In a combined approach that includes surveys of permanent transects, common garden transplant experiments and genetic analysis, we are monitoring border dynamics and assessing genetic identity and performance of clones of different patch sizes. Current results of the ongoing project indicate that (a) border zones between the invader and Spartina tend to be more defined in large Spartina remnant patches than in small patches and (b) Spartina increases in dominance at large-patch borders but decrease in small-patch borders. There appears to be large genetic differences between adjacent large- and small-patch clones that are often more pronounced than differences between clones of different regions. In contrast, small-patch clones grow faster than large-patch clones in a common garden setting.