The other day I was mooching around a rather fabulous garden, where they had everything organised and cared for to a level that I can only aspire to. I happened upon these seed drills where they'd recycled some used water bottles to water-proof their drill labels. It's such a simple but effective idea.
Attach your label to a stick, and then house it in an upturned plastic bottle, and the rain's not going to wash away your ink: genius!
All the best for now,