Simply mix with water & apply with a watering can. The nematodes that they contain are naturally occurring microscopic organisms that seek out & kill the pests. Long-lasting & weather-proof too! Vine Weevil is a nightmare pest whose larvae kill plants by eating their roots, & adults decimate foliage. Apply when the larvae are active: March-May & July-November (whenever the soil temperature is above Approx. 5C/40F). (12m Pack.) Pack contains living organism, & should be kept refrigerated on arrival, & used before the expiry date, Approx. 3 to 4 weeks from date of despatch. Please allow 7-10 days for delivery. (Please note: This product is not available in Eire.)