The 70/30 rule in gardening means keeping about 70 percent of your yard as plants and lawn, with paving, decking, and structures limited to roughly 30 percent. The split keeps a yard from feeling like a parking pad, lets rainwater soak in instead of running off, and usually costs less, since hardscape runs $15 to $100 per square foot while planted beds run $5 to $20.
Some designers flip the ratio inside the planted area: 70 percent structural evergreens and reliable shrubs, 30 percent seasonal color, so the garden still has a backbone in February.
Neither version is law. Small urban courtyards often need more hardscape to be usable at all. To find the balance that suits your lot, mock up a few different ratios with AI landscape design.