Hostas are easy to propagate by division in spring, just as they’re starting into growth. One large clump can be divided into several new plants. Potted up and grown on in a sheltered spot or cold frame, these new plants will be ready to plant out later in the year year.
To keep slugs off your hostas, focus on growing strong, healthy plants that will be more able to withstand attacks. You can also lay sacrificial comfrey leaves around the base of plants, mulch with grit, create beer traps, mulch with bran or use copper barriers. Make sure you’ve created habitats for toads, frogs, hedgehogs and birds, too, which eat slugs and snails.