Container gardening glossary

The availability and movement of air in the growing medium around roots.

A plant in the Araceae family, which includes Monstera and many common indoor foliage plants.

The total quantity of a growing mix prepared at one time.

In coir preparation, treating the material to adjust the ions held on its exchange sites.

A carbon-rich material sometimes included in mixes; its role and suitability depend on the product.

Material made from coconut husks, used in growing media in forms such as pith, fibre and chips.

Compressed dry coir that expands when water is added.

A medium becoming more tightly packed, reducing useful pore space.

Decomposed organic material used as a mix ingredient or soil amendment.

Seed leaves present in a seed's embryo, distinct from the true leaves that develop as the plant grows.

The movement of excess water out of a growing medium and container.

Openings in a pot that let excess water escape.

Electrical conductivity, used as an indicator of the concentration of dissolved salts in water or feed.

A tube used to add water to a planter's reservoir.

Mineral soil used in the ground; it behaves differently when confined in a pot.

The material around plant roots that provides support and holds air and water.

Growing plants with nutrients supplied in water, with or without a solid supporting medium.

A settling test that gives an approximate view of mineral-soil particle proportions, with important limits.

Lightweight expanded clay aggregate: fired clay pellets used as a growing medium.

Water containing dissolved plant nutrients.

Graded bark used to provide coarse structure and air spaces around roots.

An opening that limits water level so a planter's intended air space is not flooded.

Relative volumes in a mix recipe, measured with the same scoop or container.

Partly decomposed moss material used to hold moisture in growing mixes.

Volcanic glass expanded by heat into light particles used to add air space in mixes.

A measure of how acidic or alkaline a growing medium or solution is.

A blend made for growing plants in containers, often without mineral soil.

Moving a plant into a larger container when its roots and growth need more space.

A porous volcanic rock used as a relatively stable, airy potting ingredient.

The part of a self-watering planter that stores water below or beside the growing medium.

Getting a dried growing medium to take up water again.

The proportions of sand, silt and clay in mineral soil.

Describes a growing mix made without mineral field soil.

Moss used live or dried in horticulture; long-fibre sphagnum differs from decomposed peat.

Reducing the number of seedlings growing together so the remaining plants have more space.

Leaves formed after the seed leaves, with features more like the mature plant's leaves.

A heat-expanded mineral used in growing mixes to help hold moisture.

The ability of a medium or ingredient to hold water after excess water drains away.

An absorbent material that carries water from a reservoir toward the potting mix.

Material produced by earthworms processing organic matter, used in small amounts as a mix amendment.