Nematodes are recommended for use whenever larvae or grubs are present. Generally, this is during the spring and fall months. Because larvae feed on plant roots, beneath the soil surface, severe damage can be done before realizing there is a problem.
When should you apply nematodes?
Nematodes should be applied when light levels are low. They are light sensitive, so apply them in the very early morning or at dusk.
Is there a downside to nematodes?
Most nematodes are harmless, but a handful of troublesome species attack the outside surfaces of plants, burrowing into the plant tissue and causing root, stem, folar and even flower damage. Other nematodes live inside the plants for part of their lives, causing damage from the inside out.