We frequently get questions on Plants Map asking about the accession number field when adding a plant. Accession numbers are a numbering system so that each plant can be inventoried individually.
Imagine you planted a Dawn Redwood in 2013 and then you planted another one in 2014 near the first one. In several years they would appear roughly the same size. If you were trying to keep records on each specific tree you might get confused on which one was planted first.
If you labeled the tree and used accession numbers, each tree would have an ID that you could tie back to your records.
My method of creating a system for accession numbers was simply to use the four digits for the year followed by four digits for the order in which I purchased that plant or group of plants in that year. For instance, 20140051 is the 51st plant I acquired and I acquired it in 2014. I actually bought and planted 3 of them so in this case, they all got the same accession number and on the record I noted in the quantity field that I acquired 3 of the same plant.
Before I started using Plants Map Tags, I would include the accession number on each plant tag or label but now that I can scan the QR code and it takes me directly to the listing on the site, the accession number is less important but I still like to record the order in which I acquired my plants.
Many people using accession numbers have quite extensive systems allowing them to glance at a number and quickly learn a lot of information about that tree. I can’t begin to decipher Jerry Kral’s system but he knows what all of these characters represent. For his conifer Abies concolor ‘Kinky’ he uses GPK07ST3012AA. He created his own system and I bet that the first three letters are his initials and each part of the number means something to him when he glances at his tags.
The Arnold Arboretum accession number system (.pdf file) starts with the year, then a number for every plant in the order it was received. If multiple plants of the same kind are received at the same time, they add a letter. Following that, they use codes such as GR for ‘grafted plant’ or SG for ‘seedling’. They also include a letter for the source of the plant such as the letter W to denote ‘wild’ or the letter G for nursery or garden. Plant 376-2001-A is an Abies koreana or Korean Fir and it was the 376th plant received in 2001.
If you start to put an accession number ID system in place for your landscape records, my advice is to keep the code simple. A search for accession numbers in use at arboretums will yield the key to decode most of the systems they use.
Now, with the ability of a smartphone to scan a QR code on a plant identification tag that takes you directly to the listing in a database such as Plants Map, the accession number isn’t as important as it was when records were being kept on paper. I’ll keep using my system but I no longer need the number to be printed on the plant label. I just scan the Plants Map Tag!