Landmark Plastics True 1801 Sheet of Pots, Case of 100 For 30 years Landmark Plastic has been making life easier and less chaotic for growers, from propagation to patio. Our wide range of plastic containers, trays, packaging and growing systems for the horticultural industry were all designed with a deep understanding of what growers need. And what they don't. Our injection molded and thermoformed products can meet virtually any size, propagation, water conservation or transportation need.