Harvesting time will be late December / early January for the angustifolia varieties and late January / early February for the lavandins (Grosso, Super etc) but can vary from district to district and from year to year as climatic conditions determine when the crop is ready.
It is a test for fitness if you harvest manually (and also a test of your friends). A mechanical harvester is a significant investment and is not really justified until you have a large area to harvest. There are herb harvesters available for purchase but some members have made their own versions of harvesters that they use.
Most people cut by hand using sickles, hedge trimmers or serrated edged knives (scissors and secateurs tend to become seized up from the resin in the stems). It is important not to allow the cut lavender heads to fall onto the ground as they must be kept free of other vegetable matter as this may affect the oil when it is distilled with the lavender. Pruning of the bushes can be carried out straight after harvesting or left until there is more time available, as long as they are pruned before the first frosts set in.
It is preferable to distil on the same day as harvest. In France they can leave the cut lavender in the fields for up to three days, though this practise would not be wise in New Zealand. The critical factor is that the crop must be dry (even of dew) when you harvest and it should be stored in conditions where it will not sweat. Some people have stored lavender in jute wool fadges or cotton duvet covers. Others spread their lavender out on the floor of a shed so that the field heat can escape until they can get it to the still. A still can be a major capital investment and unless you intend to be a major producer, it is probably better to get access to someone who will contract distil your crop for you. At present there are several stills available throughout the North and South Islands.
It is one thing to grow and distil oil successfully but the ultimate aim of most members is to make an income from oil production and that involves looking at marketing.
Some who produce oil do it for use in their own added-value products for sale and some sell to brokers as a commodity.
Though marketing is not the role of the Association, we assist with networking among members who may be able to help and also hold workshops at our Conferences.