Why are the leaves on my Lily of the Valley shrub turning brown? I have only had it for a few months, it is planted in the right place and I have been watering it every night.

• Lily of the Valley (Pieris) prefers a slightly acid soil, similar to gardenias, azaleas and camellias.
• A position with cool moist root run with either early morning sun or late afternoon sun is ideal. 
• Feed with a balanced fertiliser for acid loving plants, Tui Enrich Rose, Camelllia, Azalea, Gardenia  controlled release fertiliser is perfect and will feed plants for up to 6 months.
• These plants have fibrous surface feeding roots, if fertiliser is over applied it can cause foliage to burn, always apply fertiliser according to pack directions.
• Mulch around the plant to keep the roots cool and moist use Tui Mulch & Feed, apply in spring and again in autumn.
• If your soil is poorly drained, such as a heavy clay soil, then that can cause root disorders and the leaves to brown. Improve drainage by creating a raised bed or by digging in organic matter to the soil.
• Reduce the watering to 2-3 times a week in summer. Avoid watering the foliage, only water the soil around the tree.
• Another cause of leaves turning brown is insect pests such as thrips, talk to your local garden centre or hardware store about a suitable insect control product.