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Gardener’s Glossary

Annual: Plants are classified by the number of growing seasons required to complete a life cycle. Annuals pass through their entire life cycle from seed germination to seed production in one growing season and then die.

Biennial: Biennials are plants which start from seeds and produce vegetative structures and food storage organs the first season. This group, which includes most of the root crops, grows vegetatively the first season. During the first winter a hardy evergreen rosette of basal leaves persists. During the second season flowers, fruit, and seeds develop to complete the life cycle. The plant then dies. Carrots, beets, cabbage, celery, and allium family are biennial plants. Foxglove, Hollyhock, Canterbury Bells, and Sweet William are biennials which are commonly grown for their attractive flowers.

Dicot, Dicotyledons: The dicotyledons, also known as dicots, are a group of flowering plants (angiosperms) whose seed typically has two embryonic leaves or cotyledons.

Monocot, Monocotyledons: Monocotyledons, also known as monocots, are one of two major groups of flowering plants (or angiosperms) that are traditionally recognized, the other being dicotyledons, or dicots. Monocot seeds typically have one cotyledon (seed-leaf), in contrast to the two cotyledons typical of dicots. Grass, corn, alliums are monocots.

Side Dressing Fertilizer

“Side-dressing” refers to giving growing plants, especially vegetables, an extra dose of fertilizer, beyond whatever food you may have applied when you planted them. Side-dressing keeps plants growing well and can result in a better harvest.

Crops that most benefit from side-dressing are corn and onions. Legumes, lettuces and root crops such as carrots and beets generally don’t need it. Others such as tomatoes, broccoli and peppers may appreciate it.

When to side-dress:
Tomatoes, peppers and okra: when they bloom.
Cabbage, broccoli and cauliflower: when heads begin to form.
Corn: when plants are knee high and when silk begins to show.
Onions: when plants are 6 inches tall, continuing every few weeks until bulb begins to swell.
Cucumbers, squashes and melons: while plants are still small and not yet spreading.

How to side-dress:
Side-dress individual plants by applying the fertilizer to the soil and gently scratching it into the soil around each plant, about 6 inches from the stem taking care not to overwork the soil too much. If you are working with a large plant or a shrub, scratch the fertilizer in a circle under the drip line (the outermost leaves). Water.

To side-dress a row of plants, scratch the fertilizer into the soil about 6 inches from the row, down the whole length. Water the plants.



No, it’s not just ‘dirt’. The unconsolidated mineral or organic material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants. Soil is formed by the physical, chemical, biological weathering of the parent material. Four components of soil: 25% air, 25% water 45% mineral components: sand, silt, clay. Remaining 5% is organic material and soil micro organisms which live in the air portion of soil.

Soil Profile:

A vertical section of a soil mass, showing the nature and sequence of various layers, as developed by natural or mechanical means.

Source: Secrets to Great Soil, pg.4, Stell

Soil Parent Material:

Rubble that hasn’t weathered enough to look like soil.

Soil Tilth:

The term soil tilth refers to the soil’s general ability to support plant growth and root growth. Tilth is technically defined as “the physical condition of soil as related to its ease of tillage, fitness of seedbed, and impedance to seedling emergence and root penetration.” A soil with good tilth has large pore spaces that allows for sufficient air and water movement. (Roots only grow where the soil tilth allows for adequate levels of soil oxygen.) It also holds a reasonable supply of water and nutrients. Soil tilth is a function of soil texture, structure, fertility, and the interplay with organic content and the living soil organisms that help make-up the soil ecosystem. Source: Colorado Master Gardeners Program, Colorado Gardener Certificate Training, Colorado State University Extension.

Soil Texture:

Texture refers to the size of the particles that make up the soil. The terms sand, silt, and clay refer to relative sizes of the individual soil particles. Sand is made up of the largest sized particles. Silt is medium sized and Clay has the smallest sized particles.

Soil Structure:

Structure refers to how the soil particles hang together, how much of the soil particles form into clods or crumbs. No matter what your soil texture, loose crumbs and clods ensure ample pore space Keep in mind that good soil structure can compensate for less-than-perfect soil texture. Abundance of organic matter is the main indicator of good soil structure. Organic matter may be all you need powdery soil or large, hard clods.


Sand, being the larger sized particles, feels gritty. There is a major difference in soil characteristics between fine sands and medium to coarse sands. Fine sands add little to the soil characteristic and do not significantly increase large pore space. An example of fine sand is the bagged sand sold for children’s sandboxes. For a soil to take on the characteristics of a sandy soil it needs greater than 50-60 percent medium to coarse size sand particles. Sandy soils have good drainage and aeration, but low water and nutrient holding capacity. Source: Colorado Master Gardenersm Program Colorado Gardener Certificate Training Colorado State University Extension.


Silt has a smooth or floury texture. Silt settles out in slow moving water and is common on the bottom of an irrigation ditch, riverbed or lake. Silt doesn’t add much to the characteristics of a soil. Water holding capacity is similar to clay.


Clay particles are very small. Clay feels sticky to the touch. Soils with as little as 20% clay size particles behave like a sticky clayey soil. Soils with high clay content have good water and nutrient retention ability, but the lack of large pore space restricts water and air movement. Clayey soils are also rather prone to compaction issues.


Technically, loam refers to a specific, well-balance soil texture. Gardeners will often use this term more loosely to describe “ideal” soil. Loam, therefore has a mixture of different sized soil particles that allow it to resist compaction, allow air and water movement, retention of nutrients and…of course, has plenty of organic material. In other words…we as gardeners strive for a “loamy” soil.

Soil Food Web:

The soil food web is the community of organisms living all or part of their lives in the soil. As organisms break down complex materials, or consume other organisms, nutrients are converted from one form to another, and are then released into the soil for the benefit of plants and to other soil organisms. All plants – grass, trees, shrubs, edibles – depend on a healthy food web for their nutrition.

Once you realize the importance of all those ‘creepy crawlies’ wandering through the top 3 inches of your soil, you’ll never say “eeeewwww” again! I promise! Yes, we’re taking care of much more than just plants when we garden. That’s why it is so important to take care not to use any synthetic chemicals and to try to avoid using even ORGANIC pesticides that would harm or disturb the delicate balance of this soil eco-system whenever possible.

“There’s an incredible diversity of organisms that make up the soil food web. They range in size from the tiniest one-celled bacteria, algae, fungi, and protozoa, to the more complex nematodes and micro-arthropods, to the visible earthworms, insects, small vertebrates, and plants. As these organisms eat, grow, and move through the soil, they make it possible to have clean water, clean air, healthy plants, and moderated water flow. There are many ways that the soil food web is an integral part of landscape processes. Soil organisms decompose organic compounds, including manure, plant residue, and pesticides, preventing them from entering water and becoming pollutants. They sequester nitrogen and other nutrients that might otherwise enter groundwater, and they fix nitrogen from the atmosphere, making it available to plants. Many organisms enhance soil aggregation and porosity, thus increasing infiltration and reducing runoff. Soil organisms prey on crop pests and are food for above-ground animals.” Source: Soil Biology, USDA, Natural Resources Conservation Service

Organic Matter:

Organic matter consists of plant and animal material that is in the process of decomposing.


Humus is organic matter in its final stage of decomposition. It is a fine, dark substance that is chemcially very complex. Humus gives rich, fertile soil its dark color. It promotes healthy plant growth in many ways, from keeping existing soil nutrients available to enhancing soil structure for good root growth.