I planted alyssum a few years ago and have enjoyed it, but it is time for a change. I have pulled most of it but it comes back. Other then pulling the new growth how can I rid my garden of it?
It is likely that you have alyssum seeds in your soil and they will continue to pop up when conditions are right for several years. Make sure you don't allow this year's plants set seed! I suppose a pre-emergent herbicide would suppress germination of those seeds but that seems excessive given how easy it is to pull/hoe the plants when they appear. It's up to you.