Pups should not be taken until a clump has at least three to four large plants to anchor it. When the pup is taken the cut must be into the mother plant enough to obtain some roots. Plant close to the surface. Large leaves are cut off of the pup leaving only the youngest leaves or no leaves at all. Some nurseries supply banana plants as container grown suckers.
Root rot from cold wet soil is by far the biggest killer of banana plants in our latitudes.
California is extremely fortunate in not having nematodes that are injurious to the banana. Gophers topple them, and snails and earwigs will crawl up to where they can get continuous water, but these pests do not bother the plant. Occasionally, a stalk will form in early summer and ripen before cold weather appears. The fruit can be harvested by cutting the stalk when the bananas are plump but green. For tree-ripened fruit, cut one hand at a time as it ripens.