Lavender for Oil

I am trying to determine what plants I want to order from you this year. I purchased your Provence and 'Lady' (360 plants) 2 years ago and I wish to enlarge my crop to 1,000 plants. I am looking for the best oil quality production. My Provence produced a good supply but I doubt the quality is there, altho I have not had it analysed as yet. The 'Lady' was not enough volumn to properly distill but even diluted I think it is of good quality. So, I am considering more 'Lady' but hear from Arthur Tucker from Delaware State University that he recommends 'Grosso' or ' Abrialii' from the Lavandin family. I am at 3200 ft., in northeastern Calif. - my plants survived 10 degrees below this winter. A hardy variety is critical. Please let me know when I need to order 5 plug trays to be delivered mid-to late May. I would also like to know if it is possible to add a 1/2 plug tray order of another variety? Do you recommend 'Lady' over your 'English Lavender'? I was very pleased with my plants and look forward to receiving more this spring.

The lavandins (Lavandula x intermedia) will never match the oil quality of the true english lavenders (L. angustifolia). 'Provence' and 'Grosso' are lavandins and they both possess an element of the spike lavender (L. latifolia) in their oil – a piney, camphorous element. But lavandins are by far the most important commercial varieties because of the bigger size, faster growth, bigger yields, and greater disease resistance (especially in the case of 'Grosso'). Both 'Provence' and 'Grosso' are very hardy; they survive our zone 5 winters reliably.
Among the english lavenders, 'Lady' has the advantage that it is easy to produce from seeds. It is not as hardy as other english lavenders, and may not even be as hardy are the lavandins; however it is a fast grower and will produce the large yields of all the english lavenders. TRhe quality of the oil will be more refined than lavandin oil, but the yield will be smaller.
We have noticed an increase in increase in commercial growing of lavender this year, so we expect that plugs will be in short supply. We suggest that you place order order as soon as possible. Sorry, we cannot mix more than one variety in one tray. We are set up for large scale production which makes it difficult to plant mix trays for individual customers.