The mention of engraved bricks reminded me that there are companies (you can find a number of them on the Internet) that make glazed ceramic tiles from any graphic you send them. I had a set of tiles so made with Latin verses from Ovid's "Metamorphoses" that describe the transformation of people into plants, for a planned section of the garden that would feature these myth-related plants. The tiles are made by a photographic process that creates a transfer, which is applied to the tile under the glaze, and you can get them in different standard sizes. These would presumably long outlast the plants, and the gardeners as well. I've also recently seen laser-engraved rocks (presumably some softer stone such as soapstone) with sentimental words and phrases meant to be set in the garden, but I did also see some beautiful and tasteful ones done from professional calligraphy several years ago. Jane McGary Portland, Oregon, USA