Texture relates to the amount of light reflected by the leaf top or bottom surface. Texture for the top of the leaf or the bottom of the leaf may be described as either dull, slightly shiny, very shiny or glaucous bloom. Glaucous means that the surface is covered with the waxy coating that reflects blue light.

Substance refers to the thickness of the leaf tissue as measured between the veins. Hostas with a thick substance, are stiffer and more rigid in how they present their leaves. Those with thin substance are more flexible and may be droopy to one extent or another.

Mr. PGC Comment: It appears that leaves with thin substance are the preferred diet for slugs. However, as with all generalities, this one too needs a bit of explanation. My observation has been that this is true in a garden with a "typical" level of slug population. Here, the tissue paper thin leaves of plants such as H. 'Eleanor Lachman' will be totally tattered by the end of the season while nearby, thicker leaved plants such as H. 'Sagae' will appear relatively undamaged.

However, in gardens where large amounts of organic mulches are used and the gardener irrigates a lot, the population of slugs will grow accordingly. Under these conditions, the slugs will need more food and will also chew on the thicker substance plants.

Lists of a few hostas with a) Thick Substance or b) Thin Substance.