Asparagus can be badly damaged by slugs. You first notice the damage when the spears appear to grow curved to one side. The slugs chew the tissue on one side of the spear causing it to grow distorted as the side opposite the damage continues to grow.
At Rosemoor we use a number of methods to control slugs but one of the most effective on asparagus is a biological control using a nematode, sold as Nemaslug. This can be very effective providing the soil is wet enough for the nematodes to spread through the soil in search of food i.e. slugs. It does not work on snails.
Because the nematodes require plenty of soil moisture to be effective we apply the solution in the rain, and when the next few days are also forecast wet – the wetter the better.
Applying Nemaslug on wet ground to control slugs on the Asparagus bed.