Most plants grow 1-3 feet tall with similar spread. There are a few varieties that will grow 3-5 feet tall and wide, I have a giant blue hosta, the leaves are very large. It took three seasons for the plant to mature and grow to four feet wide.
Fertilize the 3-4 times during growing season. Use very light mulch or pine needles to control slugs, to retain moisture, and to control weeds. Don’t mulch over 2 inches as it may increase the garden pests; vole, slug and snail.
Remove pests by hand daily and repel pests naturally with coffee grounds. Scatter the spent coffee grounds around the plants. Coffee will also deter cats from your hosta garden.
Hosta will grow and multiply but never become invasive. Divide clumps every 3-4 years in spring.
Do not plant in an area of dense shade as they do need some light from the sun to grow well. My hosta garden gets part sun in the morning and all are very healthy.