A very detailed study of about 1500 accounts of tours of Wales has shown that the custom of placing of flowers on graves was practiced over most of Wales probably as early as the 17th century and definitely during the 18th and 19th centuries. There is very little evidence for this custom in England, Scotland and Ireland until it became popular in England from the 1830s, probably as a result of the opening of large non-denominational cemeteries on the edge of towns. There were two distinct customs relating to the placing of plants and/or flowers on graves in Wales. The first was practiced immediately after burial and then at intervals afterwards. The second custom was practiced on the Saturday before Palm Sunday (Sul y Blodau, Flowering Sunday) or occasionally for Easter Sunday and Whitsunday. This seems to have become very popular in south-east Wales and just over the border in England from the middle of the 19th century. By the early 20th century, it appears to have spread into much of Wales where it is still practiced today, but apparently not in England.