Any organism that causes disease, generally applied to bacteria, viruses, and less correctly, fungi. Peat Partially decomposed mosses and sedges harvested from bogs and used as a component of soilless mixes. Peat pots Planting pots made from compressed peat. These are used for plants that resent disturbance, as at transplanting time the entire pot can be set out in the garden and the young plants roots will grow through the walls of the pot. Pebble tray Grouping potted plants within a shallow, pebble filled tray in order to maintain humidity in an environment with central heating.
Water is poured into the pebbles and evaporates up and around the plants.
The stem of a flower. Perennial Any plant that lives more than three years. Perlite Small globules of heat expanded volcanic rock used to increase the porosity and drainage of potting mixes. Often used in the rooting of cuttings as it is both inert and sterile. Petal A specialized leaf that surrounds the reproductive parts of a flower.