Glossary

Potassium Soap or Agricultural Soap

Contact insecticide based on potassium salts of fatty acids. Aphids, whiteflies, and young mealybugs.

NPK

The three numbers on the package: leaf, root/flower, and fruit. How to read them without magic.

Drainage in Pots

Without water drainage, even the most expensive substrate turns into a swamp with yellow leaves.

Seedling Tray

Container and technique for germinating with moisture control and separated roots.

Weed Control Fabric

Permeable fabric that blocks light to weeds while allowing air and water through.

Agricultural Hydrogel

Polymer that stores irrigation water and releases it to the roots when the substrate dries.

Expanded Clay or Arlite

Lightweight expanded clay balls for drainage, hydroponics, and preventing waterlogged root balls.

Vermiculite

Expanded mineral that retains water and cations. Ideal for overly dry terraces.

Perlite

Expanded volcanic rock that aerates the substrate and prevents compact root balls.

Soil pH

pH determines if the plant absorbs nutrients or just looks at them. Definition and useful ranges.

What is a plant support?

Definition of plant support: its purpose, materials (bamboo, steel), and when to place it in the garden.