Willows, in botanical genus Salix, comprise nearly 300 different species of trees and shrubs. Fast-growing and winter deciduous, a willow grown indoors becomes problematic especially if you lack space, large soil containers and abundant sunlight.
Most willows are trees and shrubs too large to grow indoors unless you have a tall conservatory or atrium. Focus on dwarf varieties of shrub willows, such as those named Boydii, Wehrhahnii, Nana or Gracilis. Also, creeping willows (Salix repens and Salix reticulata) may be good choices.
All willows appreciate a fertile, non-alkaline soil and often favor moist to wet soils. When grown indoors with lots of light, their growth rate causes root constriction and health and vitality problems. Willows also hail from temperate or high elevation habitats and must endure a cool winter dormancy. This doesn't typically occur in an occupied building.
Besides fast growth and mature plant size, willows remain susceptible to many diseases and insect pests. If the willow is stressed for any reason, fungal diseases and blight may further harm it, and common indoor pests like aphids and scale frequent willow.