To enjoy lavender's scent at its best, remember this advice from Mountain Valley Growers: "The plant cools itself by releasing its fragrant oils, so the more heat they are exposed to the less oil, and fragrance, for you."
Lavandin (Lavandula x intermedia) represents an English and a spike lavender cross. Lavandin is used as a fragrance commercially, according to the Arizona Cooperative Extension, Mojave County. The extension lists the variety 'grasso' as probably the most fragrant lavandin.
Seal lavender is recommended by Mountain Valley Growers as highly fragrant and old-time favourite that makes good hedging.
English lavender (L. angustifolia), described as very fragrant by the Arizona Cooperative Extension, Mojave County, originates from northeastern Spain.
Provence lavender is best for potpourri because the buds come away easily and the flower dries well.
When looking for a fragrant type to grow at home, gardeners should be aware of the difficulties of growing lavender. Mountain Valley Growers warns that lavender seed takes a long time to sprout and demonstrates a low germination rate; the plants are slow to reach transplant size. The website also notes that lavandins, "either do not make seeds or the seeds are sterile."