Turf and tree decisions turn on a few numbers you can check: the soil temperature that triggers seed germination or crabgrass, the USDA hardiness zone a species survives in, the inches of water a lawn uses in a week, and the mowing height each grass tolerates. Our turf and tree guides take those numbers from university extension services, the National Turfgrass Evaluation Program and manufacturer manuals, and link each one with the date we checked it.
Each guide names the cultivars, products and rules it relies on, so you can look them up yourself. Where a question has a threshold, such as when to aerate or whether to overseed or start over, you will find it in a decision table near the end of the page. Our methodology explains how we compile and date the figures.
For prices, the cost guides cover the jobs these pages describe, from grass seed and sod to aeration and tree planting.