Brown Leaves on Lily Plants

Watering

• Among the most common causes of brown leaves in lilies is improper watering. Overwatering has a negative effect on roots, and makes them unable to properly transport nutrients and water throughout the stems, leaves and flowers. If watering methods aren’t corrected, this root trouble will often result in browning of the leaves and eventually death of the plant. Too little water tends to trigger a stress response, which often results in brown leaf tips and, if prolonged, will result in plant health deterioration. The key to watering a lily is to do it slowly and not focus on one spot. Each type will have its own frequency needs, but a good rule of thumb is to keep the soil evenly moist, but not leave standing water around the base of the plant.

Fertilizer

• Fertilizer, particular liquid chemical fertilizers are a primary cause of browning leaves in lilies and most other plants. Over fertilizing is especially problematic, as fertilizer burn is a common result. Though a necessary part of plant life, nitrogen in excessive amounts is particularly harmful, and potentially fatal. Instead of fertilizer, thoroughly mix a well decomposed compost into the soil. This will help keep much-needed nutrients available without overloading on certain minerals and causing burns.

Pests and Disease

• Pests and disease are part of every garden, and are particularly harmful to plants which are not at optimal health or are under stress. A number of bacterial and fungal infections will cause browning of lily leaves, but root rot is among the worst. This is an illness in the roots caused by pathogenic bacteria which are most prevalent during seasons of heavy rain. The bacteria enter through the roots and colonize there, eventually turning them into a useless gray mush which is unable to function properly. Even if caught early, root rot is often fatal. Instead, regular treatment with a bactericide or fungicide, proper soil drainage and removing debris from the base of plants will greatly reduce the risk of infection. Several insects, when present in large numbers, will also cause leaves to brown. Among the most wide-spread are nematodes, caterpillars, aphids and spider mites. Maintaining overall plant help will greatly reduce the damage done by insects.

Nutrient Deficiency

• All plants require approximately 16 nutrients in order to thrive, among them are iron and nitrogen, both of which are key to chlorophyll production. Chlorophyll is the plant material which turns leaves green and without it, leaves will turn yellow then brown. If left uncorrected, nutrient deficiencies will result in reduced leaf size and will hinder flower production. Iron shortages will present with leaves that discolor at the margins and move steadily inward. This is repaired by aerating the soil and introducing an iron chelate. Nitrogen problems with present with a more all-over, even discoloration and is treated by mixing compost into the soil.