When to water, how much to give and how to read the soil, for garden beds, lawns and trees

Root Zone is about getting water to the roots and stopping there, whether the roots belong to a vegetable bed, a lawn or a young tree.

The three sections

• Watering covers how much to give and how often, and how to read a plant that looks wrong.

• Water quality and soil covers what is in the water and how the soil it lands on takes it in and holds it.

• Crops, drought and climate follows particular crops and the dry and wet years that decide how much watering a season takes.

First reads by subject

• Garden beds: telling overwatering from plain thirst

• Lawns: letting a lawn go dormant in summer and a water audit of the sprinklers

• Trees: a new tree’s first two summers and watering trees in winter

• Soil moisture: how sand and clay take in and hold water

• Drought and saving water: what causes drought and plants that get by on little rain

Rules that hold in most gardens

• Check the soil before watering. A finger or a trowel pushed a few inches down says more than the calendar, and a soil moisture sensor does the same job for a bed on a timer.

• Water the root zone deeply, then let it dry a little. A soak that wets the soil where the roots are builds deeper roots than a daily sprinkle that wets the top inch.

• Let the soil and the weather set the timing. Sand needs smaller, more frequent waterings than clay, and how much of a storm reaches the roots decides whether the next run is needed.

• Mulch bare soil. Two to three inches over the root zone slows drying between waterings.

No single schedule fits every garden. The plant, the soil, the weather, the age of the planting and any local watering rules all change the answer, so the pieces give ranges and the reasons behind them. Every piece is dated, and the full list, newest first, is under all pieces.