Referring to a plant’s active growth behavior.
When used in horticulture terms, aggressive means that a plant is a really good grower. It’s not quite invasive but it will tend to spread in the garden. When you hear this term, ask someone who has had experience with the plant in question, as this term can be very relative and dependent upon the person’s perspective!
AGRICULTURE
The art and science of cultivating land for production of food and for other uses by humans.
ALKALINE
Soil with a pH of 7.1 to 14.0. (See: pH)
ALTERNATE
Generally referring to leaves that are arranged on the stem in alternating fashion. (See: Leaf Pattern)
Asimina triloba (Pawpaw)
AMEND/AMENDMENT
Anything added to your soil to improve plant growth.
In a perfect world our garden soil would be the ideal mix of sand, silt and clay, nutrients, and pH, and we would never have to amend the soil. But the reality is that more often than not, we need to help our soil by adding materials that either enhance its physical and chemical properties or provide additional nutrients. You add organic matter to the soil as an amendment in order to improve root growth and thus plant health. Amending the soil improves the structure and its ability to perform functions such as water retention, permeability, water infiltration, drainage and aeration. You can also add nutrients to amend the soil in order to improve plant growth.
Amending the soil can be accomplished through different methods. You might hear of gardeners “top dressing” their garden. This is simply adding or amending their garden with a layer, perhaps an inch or two, of organic material, such as leaf mold. Amending the soil when planting a new flowerbed, tree or shrub is also a common practice. By giving the newly installed plant an extra boost of good nutrients and rich, organic matter, the plant is more likely to take hold and thrive (not just survive) in the landscape.
Additionally, some amendments are designed to alter the pH of the soil, making it more acidic or alkaline.
ANAEROBIC
Without oxygen. (See: Aerobic/Anaerobic)
ANGIOSPERM
A flowering plant whose seeds are housed within an ovary.
Not a word you are likely to see on a plant tag or in a beginner’s gardening book, huh? Angiosperms run the full gamut of garden plants, from trees and shrubs to annuals and perennials, even grasses. Gardeners do not say, “I am off to find new angiosperms for the garden!” Rather, the term is most helpful when reading advanced garden books or keying out plants.
Asimina triloba (Pawpaw)
In contrast to angiosperm is a gymnosperm, a plant whose seeds are not protected in an ovary. Examples of gymnosperm plants include conifers such as pine, spruce, hemlock, and Ginkgo.
ANNUALS
Plants that complete their life cycle within one growing season.
For gardeners, mainly in northern colder winter climates, annuals are planted after spring’s final frost and last until they are killed by the first frost of autumn. This is different than perennials, whose growth from the soil line above is also killed by the frost, but will re-grow from the root system the following spring.
Zinnias are one example of an annual.
ANTHER
(See: Flower)
ARBOR
A permanent garden structure, often made of wood and enhanced with lattice or other material fashioned from cut branches or strips of lumber to create an open and airy yet shady spot in the garden.
Passing under an arbor, one often feels as if they are transitioning from one area of the garden to another, from the sidewalk to the front yard or into another garden space – or, if the arbor is large enough, it can be a shady spot in the garden to sit and rest a while. As a year-round, visually interesting element in the garden, arbors are priceless. As structures on which to grow vining plants such as Wisteria, Clematis or climbing roses, arbors are a gardener’s delight.
Arbors can be rustic and casual, like those in a cottage garden, or more refined and architectural in nature. They can be made of wood or even metal. More ornate arbors are often meant to stand alone without plants that may obstruct the arbor’s detail work.
ARBORIST
An individual trained in the art and science of planting, caring for, and maintaining individual trees.
ARCHING
(See: Habit)
AROMATIC/FRAGRANT
Having a pleasing scent from a plant and/or its parts.
What is that wonderful scent wafting through the garden? When we think
