OFFSET – A young plantlet which appears on a mature plant.
OPEN POLLINATED – Any plant that has been pollinated in the field.
ORGANIC – Fertilizers and chemicals that have been obtained from a source which is or has been alive. A type of gardening using no chemical or synthetic fertilizers or pesticides.
ORNAMENTAL – A plant that is grown strictly for its foliage or flower rather than for food or any other economic use.
OVER POTTING – Repotting a plant into a pot which is too large to allow successful establishment.
OVERSEEDING – Planting on top of an existing garden or lawn. Rye grass over lawns for winter. Wildflower seed in meadows.
PARASITE – Any plant that grows upon another.
PARTERRE – Ornamental garden beds that have been geometrically designed and separated by walkways.
PEA GRAVEL – Gravel about the size of a pea.
PEAT – The preserved and compressed remains of dead bog plants.
PEBBLE TRAY – A tray filled with pebbles to create humidity in the environment.
PELLETED SEEDS – Seeds that have been coated with an inert material just to make the handling of the seed easier.
PERENNIAL – A plant which will live for three years or more under normal conditions.
PERFOLIATE – Paired leaves which fuse around the stem.
PERGOLA – Sometimes called an arbor, or walkway covered with trellis work.
PERLITE – Granular volcanic rock, used to improve the aeration in potting soil. No nutrient value.
PERMACULTURE – A very advanced system of trying to grow and provide food by using perennial plants instead of the annuals the agriculture world uses now for most of our food.
PETAL – One of the divisions of the corolla – generally the showy part of the flower.
pH – The scale where the acidity and alkalinity of soil is measured. It starts at “1″ for acid and goes to “14″ for alkali. Most gardens will fall between 5.5 – 8.6.
PHOTOPERIODISM – The response of plants to the length of a day and night .
PINCH OUT – Pinching with the fingers to remove the tip of a growing shoot to encourage lateral growth.
PIONEER PLANTS – The very first species to grow of the soil has had a traumatic occurrence, like a fire, flood, earthquake.
PIP – Used in propagation. The side offshoot of a rootstock. A good example is lily of the valley.
PLANTLET – A small plant off the original plant.
PLANT LICE – This is a reference to aphids found in British publications.
PLEACHING – a popular technique of training and pruning shrubs and trees into a wall.
PLUG – A small but well-rooted seedling raised in a cellular tray for covering large areas as in ground covers or lawns.
POCKET GARDEN – A small growing area planted with miniature and dwarf varieties.
POLLEN – The yellow dust produced by the anthers.
POT BOUND – A plant growing in a pot which is too small to allow proper leaf and stem growth.
POTPOURRI – A mixture of sweet smelling leaves, petals, blooms to create a perfume in a room.
POTTING UP – Taking the young seedlings or transplants into a specific container for mature growth.
PRE-EMERGENT WEED KILLER – Using a herbicide to kill the weed seeds to prevent them from germinating.
PRESSURE TREATED LUMBER – Lumber that has been treated with chemicals to prevent rotting.
PROPAGATION – Refers to the many different ways of starting new plants.
PRUNING – The cutting off leaves or branches within limits in order to remove dead or diseased foliage or branches.
RADICUMS – These plants are special in that their stems have roots that will cling as they grow vertically or grow over the ground.
RAISED BED – Any ornamental or vegetable bed that has soil higher than the surrounding immediate area.
REED – Tall grasses that grow in shallow water.
REMONTANT – Plants that will bloom more than once a year.
RE-SEEDING – Plants that drop their seeds for next season.
RESTING PERIOD – A period of dormancy where energy is restored to the plant.
RETAINING WALL – A wall that has been built on a slope to keep the soil from sliding or eroding.
REVERT – Sometimes a particular cultivar might change back to one of its original species.
RHIZOME – A thickened stem which grows horizontally below or on the soil surface, as in iris rhizomes.
ROCK GARDEN – An area constructed of larger rocks arranged to look natural.
ROOT BALL – Matted roots plus enclosed soil within the pot of a container grown plant or when plant material is transplanted.
ROOT-BOUND – Often, when plants are left too long in their container, the roots become entangled and begin to grow in circles.
ROOT CROPS – Any vegetable that the roots are edible: i.e. carrots, potatoes, turnips.
ROOT CUTTING – Plants that grow away from the mother plant and root, can be dub up and transplanted.
ROOTING HORMONE – A chemical in powder or liquid form which promotes the formation of roots at the base of a cutting.
ROOT PRUNING – This is done in two instances. One when repotting from one pot to another, roots that have grown in a circle are trimmed to promote future growth.
ROOT ROT – Quite common in plants that are effected by fungus diseases and have poor drainage.
ROOTSTOCK – The roots and stems arise from this part of the plant.
ROOT ZONE – The entire area where roots are growing below the plant.
ROTATION – Specifically towards crop rotation: changing the plants in the same growing area.
ROTENONE – Material used a lot by organic gardeners.
RUNNER – A creeping stem which produces small plantlets along its length.