Lavender is wonderfully versatile in the garden. The mounded foliage serves as a backdrop to flowering plants when the lavender itself is not in bloom, but oh!, when the lavender is in bloom... Take advantage of the height that lavender provides, and the blooms being borne aloft, release their scent as they sway on the breeze. Because of the scent and the ‘sway’ we like to plant Lavenders in small groupings of 3 to 5 plants to get the maximum impact.”
For companion plants we like to use other heat tolerant plants that can the handle the “Mediterranean” style of care that so many Lavenders enjoy think sunny and dry. Other herbs that like sun and similar conditions are Rosemary and Oregano. If you are using tall Lavenders types such as L. dentata then the Rosemary and Oregano can be planted in front.
With flowers we like to use heat loving Penta or Gazania with Lavender. Portulaca as a spreader looks nice in the foreground and the new sun loving Coleus add great color contrast to the often grey-green foliage of many Lavenders. Other good choices include Echinacea, Arctotis, Euryops and Scabiosa
Lavender's color and shape go nicely in many situations. Combine lavenders with other varieties of lavender, with herbs in a kitchen garden, and with a host of favorite blooms, such as Pentas, Celosia, Rudbeckia, Pentas, and Cuphea. Lavenders can also make a wonderful set of bookends with bright flowers such as Gerbera and Delphinium.