Plants need air too, not just soil

A sometimes overlooked necessity for plant life is air (and not just carbon dioxide). Without air, plants struggle and perish. Yes, the free oxygen in the air is part of the photosynthesis recipe, produced by the plants themselves, but another practicality is even more visible here. Air movement around your plants prevents disease, especially fungal diseases that gain a foothold when the air is too “close” and humid and when wet leaves can’t dry or don’t dry quickly.
Underground, oxygen between the particles of soil is important. Plant roots, or more accurately, their little root hairs, are busy. They take in that oxygen, absorb water, and then release carbon dioxide. If this process is thwarted, as in waterlogged soil, the roots can’t function properly, they begin to rot, and the plant surely suffers.
I’m not suggesting you set up a fan out there in your garden, but here’s what you can do to make sure your plants are getting plenty of air:

• Don’t let soil get compacted. If it’s quite wet, don’t walk on it or dig in it. Loose soil is airy soil.
• The addition of organic matter, especially in dense clay soil — something I keep harping on, I know, but it’s so important — helps keep it aerated.
• Never kill an earthworm. Earthworms help break up and aerate your soil. Rejoice in their presence! Welcome them!
• Make sure your garden is well-drained (see the preceding section on drainage).
• Don’t crowd your plants together in the garden bed if they’re susceptible to mildew or black spot. Give everyone a little elbow room!