When the plants bloom in late July, the flower spikes continue to lengthen for several weeks, extending their bloom. Their long stems and productive nature make them the first choice for many commercial flower growers, and they'll find favor in your garden, too. Despite what most consider an inferior fragrance, lavandins today account for most of the lavender oil produced in France because of their high yield per acre. The darkest lavandin is 'Grosso', which has a nice compact flower spike, excellent for drying. It also has a neat habit and a fragrance sweeter than that of many other lavandins.
Spanish lavender is a low, sprawling plant, with squat flower spikes and a hint of pine fragrance.
Hardy to Zone 8, it is often in full bloom as early as May in our Oregon garden. Silver Frost' is more cold and humidity tolerant than most wooly lavenders. French lavender has the same blocky flower spike as Spanish, but with a smaller tuft of bracts. Its leaves are slightly serrated along the margins, as if cut out with pinking shears. Both flowers and foliage are thickly resinous with the scent of lavender and camphor.