It's important, isn't it, to think of the garden as a wonderful place to be, full of wonders, (not necessarily rarities) and enchantments at all seasons. Some mischief has been done, probably, by calling the garden an "outdoor living room," as if any living room in the world had such wonderful things in it as a garden has. And as for "plant material," that is one of the supremely vulgar phrases of this language, and I hope if anybody has been using it, he will stop immediately. It is a barbarism. Plants are not "material." The phrase is commonly used by people of careless habits, indifferent brains, and, I suspect, no morals whatever. We do not want, therefore, any "plant materials" in any "outdoor living room," but we do want bushes, herbs, flowers, water-plants, and so on, and while we all have sense enough not to expect the impossible, we have a right to expect the magical. [From "Reflections on Gardening" in The Essential Earthman.]
I hate the term "plant material" as much as I hate the term "text." It's not "plant material;" it's a plant! It's not a "text;" it's a book! "Text" and "plant material" sound like things that have no life of their own.