The cheapest way to landscape a backyard is to do the work yourself in phases, using mulch, seed, and small starter plants instead of mature stock. DIY landscaping typically runs $1 to $4 per square foot, against $10 to $20 or more for a professionally installed design.
Concrete savings add up fast. Buy perennials in small pots and let them grow in, divide plants you already own, and use wood-chip mulch, often free from local arborists, for paths and beds. Seed a lawn rather than laying sod. A pea-gravel seating pad costs a fraction of a paver patio. Tackle one zone per season so the spending spreads out over a year or two.
A clear plan prevents the most expensive mistake, which is redoing things. Mock up the whole yard on a photo with AI backyard design before you buy anything.