PMCGrady - I wonder if the cement tiles were used as a method of blanching the celery, instead of planting in a furrow and backfilling or mulching. I have read of people covering with cardboard sleeves, but they tend to not weather very well, or succumb to mild/mildew... The cement would keep the suns rays away, and also hold moisture.
__________________
"He who has a library and a garden wants for nothing." -Cicero
|