How to aerate your lawn Aeration relieves soil compaction, allowing air, water, and nutrients to penetrate the soil making your grass stronger and supporting drainage You want to go in 4 to 5 inches deep, plunge it in and then pull it back a little. Pull it out and repeat every 6 inches across the garden. You can leave the holes open or fill it with horticultural sand for drainage #gardening | The Michael Griffiths