how old are the lupins? because new plants are more likely to be affected by aphid and mildew than old plants.
i once read that if lupins survive the first year of aphid and mildew attack, they build up an immunity, so by the second year the aphids and mildew should be less bother, if no bother at all. The plants can be helped by spraying, cut down the old growth about 2 inches from the base after the lupins have seeded, new growth should be less affected.
also look out for new plants that are not affected whilst others are. These plants will have a genetic immunity. Breed from these plants by sowing from their seed. The seedling should also have the genetic immunity.
all the best x
Last edited: 20 August 2016 13:50:22