Over the last month I have been updating the calendar at veggiegardener.nz Going back over the original data has been an interesting journey. I have been double checking everything by adding it to a massive database I am crating from of credible planting calendars and writing from New Zealand and abroad overlaid by my experience and knowledge.
The thing that struck me was that although most information on planting times agree, there are vast differences as well. Some say only plant certain seed in cold areas in November while others say only plant the same seed in warm areas in November. Having pinned down a good working model for the calendar I decided to do some research into the origins of the plant calendar times we use.
I traced the existing planting information back as far ancient Egypt around 4236 B.C, it was taken from here to China by tea traders to the valley of the Yellow River, during the Shang Dynasty (1600–1046 BC) for the gardens of the kings and noblemen. From China, the calendar was bought to France by astronomers and used extensively by André Le Nostre in the gardens of King Louis XIV. His enthusiasm for the calendar popularized it and bought it to the greater French population. (As with all the movements of the calendar the aristocracy often bought it into countries and spread the information from there). German peasants developing Hügelkultur took on the calendar taught by traveling French missionaries. (an awesome technique of a composting process employing raised beds constructed from decaying wood debris and other compostable biomass plant materials.)
The Egyptian calendar appeared again in the first botanic garden in England, the Oxford Physic Garden, in 1621. From there it became the leading planting calendar for England (with a few tweaks). It is this adapted calendar that was bought to the colonies and used by early New Zealand settlers. Nowadays it has evolved with some copying from more original calendars back in London and France. This provides the base of information for of what we read today in publications and online calendars.
Although the times and places I have written about here are derived from fact the story I have woven around them is not. The story however does hold true to my imagined history of how our calendar information has been formed. Fortunately I believe that we have a workable solution to this problem. When we release our updated diary in the next few months it will revolutionise the information available by using real data from real gardens. When you, our gardeners, use the diary it will be able to harvest planting information and feed it straight back to the communities (your community) that it came from. I love the idea that in a few years we could leave the primitive generic data behind and be working with a real time calendar tuned to local climate and environments.