You just need to grate a bit of a cucumber (with a grater) Dont aim for too much as remember - it is a fruit, so you only want to do this just to coach him into eating his new weeds. But a little drizzle, a bit of rind, and mix up with your fingers should do the trick, nice and moist. Then dust with nutrobal or your suppliment. The moisture on the leaves will make the suppliment stick so its a really good trick xx
