All plants have a natural form that they will grow into with time. As a mature plant, hostas each have a form and this should be used in the landscape to "play off" against other forms to relieve monotony and provide contrast.

It is important to remember that this factor applies to a mature clump of hostas. Many types will show one form of the other as a juvenile plant or seedling but, in a few years' of growth will transform into its mature form. Generally, it takes 5 or 6 years for a hosta plant to be considered a mature clump.

Generally speaking, hostas have two major categories of form and several sub-forms including:

1. Dome (rounded) Shaped

2. Upright (vase) Shaped

3. Rhizomatous

4. Irregular Shape

1. Dome Shaped Hostas - The majority of hosta species fall into this category. They form a rounded mound of foliage that is often as wide as it is high.

Sub-forms would in cultivars that form a flat mound. These plants are wider than they are  high. Hostas with the species, Hosta longipes in their background fall into this category.

Another sub-form would be what is often called a "cubed" mound. These plants are taller than they are wide but do not have the extra long petioles that characterize the upright hostas. H. 'Summer Fragrance' would be an example of this type.

Finally, some hostas spread by rhizomes (not stolons as is commonly thought) and tend to hug the ground as they spread out and eventually form a rounded mound of many individual plants.

2, Upright Shaped Hostas - Plants in this category resemble an upright vase when in a mature clump. This is mostly do to the fact that they produce very large, tall petioles which hold the leaves up high and point them toward the sky. The classic example of this type of hosta is H. 'Krossa Regal' and another is H. 'Yellow River'.

A sub-form would include members of the Hosta sieboldii species that have shorter petioles but the leaves tend to aim upward in an erect form.

3. Rhizomatous Hostas - Certain plants develop underground stems called rhizomes which move out away from the plant and have the ability to start offshoots. Some, mostly smaller hostas, propagate this way and are divided by simply pulling apart the mass of rhizomes.

4. Irregular Shaped Hostas - Most hostas have some regularity to their form whether it is mounded or upright. However a few cultivars do not have such discipline and seem to be like untidy teenagers that throw their leaves around in all directions without any thought.