PlantAeration.
The proportion of air-filled pore space in a growing medium and the exchange of oxygen and carbon dioxide between that space and the atmosphere.
What it means for your plants
Roots respire and need oxygen; in a saturated mix oxygen runs out within hours to days and root tips die first. Most foliage houseplants do well in mixes with roughly 15–25% air-filled porosity after draining, which coarse bark, perlite or pumice help provide.
IN PRACTICE
Adding one part perlite and one part fine bark to a bagged mix keeps an aroid’s root ball airy rather than soggy.
Put it into practice
Choose a suitable houseplant potting mix, understand bag labels and ingredients, and avoid drainage mistakes without relying on a universal soil recipe.
Potting mix vs. garden soil: what to use for houseplants
