Black Eyed Susan
Roses make great companion plants with lavender. Pink roses are a wonderful choice. Shrubs and floribunda varieties grow well with lavender.
Coneflowers, as they are also called, can blend in or stand out with lavender, based on the colors they bloom in.
Alliums smell great and will bring in plenty of pollinators for you to enjoy in your garden.
Various herbs, such as mint, rosemary, and basil also make great plants to grow with lavender.