How Much Light Does a Lavender Plant Need?

Types

• Between 30 and 40 species of wild lavender species exist. Over the years, horticulturists crossbred some of the more ornate species to create hybrid species and dozens of cultivars. While all lavender plants need abundant sunlight to prosper and bloom well, tolerances to heat, drought, soil moisture and air circulation differ among the species. Some species display silver, woolly foliage with fernlike lobes while others' leaves are oval lances and simple light green. Root and stem fungal rots tend to kill lavender plants when summer heat is accompanied by high humidity, lots of rain and overly moist soil.

Sunlight Needs

• Ask an experienced herb or rock gardener or consult a horticultural book, and you'll always see lavender plants discussed in landscapes with a full sun exposure. Plant lavenders where no less than eight hours of direct sunlight reaches plants daily. Lavender plants may survive in lower light levels, but stem growth may be spindly, flowering absent or plants slow growing and stunted in size.

Benefit of Full Sunlight

• Sunlight shining on lavender plants improves growing conditions. The warmth of the sun heats the soil, dries morning dew or lingering rain droplets from leaves, and helps keep the inner, lower stems and soil dry. Lack of sunlight slows the warming of soil in spring, which coaxes lavenders to start growing and produce their flowers. Too much shade, from nearby trees or buildings, also slows evaporation of moisture and can promote fungal diseases to attack lavender plant tissues. Blackened leaves often result from buildup of fungi such as mildew on stems and leaves, eventually killing the lavender plant.

Shade May Be Helpful

• While full sun locations promote healthiest growth and flowering on lavenders, a midafternoon break from hot, intense sunlight can be beneficial. In lowland desert areas or where summer temperatures readily climb above 90 degrees Fahrenheit, dappled shade on lavender plants from approximately 2 to 5 p.m. lessens their water needs and prevents plant wilting. Moreover, plants grown in containers heat up and dry out faster than those grown in the ground. Providing a few hours of afternoon shade keeps container soil and lavender roots cooler, diminishing the need for as much irrigation.