Lavender is a beautiful, drought-tolerant plant that generally requires minimal water. Depending on the climate and the type of soil, lavender plants generally require supplemental watering once or twice a week, particularly during hot and dry summers. Before watering, check the soil for moisture; if the top two inches are dry, give the plant a thorough, deep soaking. Drip systems and soaker hoses are great for watering lavender. Make sure not to over-water, which can cause rot. Reduce watering during the winter months, when lavender plants are dormant.
