Answer: Lavender is native to the Mediterranean and as such it requires extremely well-drained soil and full sun. Its roots will quickly rot in soil that stays too moist. So, if you pot it with other plants, they must have the same moisture and sun requirements. Rosemary, another Mediterranean herb, is an option.
Drip irrigation is preferable because overhead sprinkling can promote fungal disease. Another key to maintaining healthy vigorous plants is proper pruning. Until the plant is about 9 months old, pinch off all emerging flowers to put energy into the root system. Each year for the life of the plant and preferably after flowering, cut back 1/3 to 1/2 half the plant, just above where the wood begins. It seems drastic but is critical.
Enjoy your lavender!
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