How often to water hydrangea in California

In July, established hydrangea in loam needs a deep watering about every 5 days in the Central Valley, about every 11 days on the south coast and about every 5 days in the South Inland zone. Sandy soil holds less water, so waterings come closer together. Clay stretches them. Check the soil before each watering and skip one after a soaking rain.

In July in the Central Valley, established hydrangea needs about 1.7 gallons a day for a plant 4 feet across and about 6.9 gallons a day for a plant 8 feet across. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Yes. WUCOLS rates hydrangea separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, high water in the Central Valley zone, moderate water in the South Coastal zone, high water in the South Inland zone, not suited to this region in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

On hot days the huge leaves lose water faster than the roots can replace it, so afternoon drooping is normal and not proof of dry soil. If the plant perks up by evening and the soil is still moist an inch or two down, leave it alone, since watering a wilted plant in wet soil invites root rot. Only a plant that is still limp the next morning truly needs a drink.

Yes. Hydrangeas want moist soil, not waterlogged soil, and standing water pushes air out of the root zone until the roots rot. The warning signs are yellowing leaves that drop, a plant that wilts even though the bed is wet, and soil that never dries at the surface. Let the top inch or two dry before watering again, and improve drainage in heavy clay.

Keep the root ball itself evenly moist through the first summer, not just the surrounding bed, because a nursery root ball dries out faster than garden soil and roots cannot yet reach beyond it. Check by pushing a finger into the original root ball, water slowly at the base when it starts to dry, and mulch right away to protect the shallow roots.

Yes, drip suits them well as long as it covers enough ground. The root system is shallow and spreads wide, so use several emitters or a ring of in-line drip tubing around the dripline rather than a single emitter at the stem. Drip also keeps water off the leaves and flower heads, which cuts down on leaf spot and keeps blooms from flopping under spray.

In the ground, usually not. The plant is bare and dormant, and winter rain covers it across most of the state. Water only during a long dry spell between storms, and keep an eye on containers, which dry out faster than garden beds even in cool weather. Regular watering resumes as new leaves push out in spring.

Crispy brown edges usually mean the plant dried out between waterings or got scorched by hot afternoon sun, and the two often happen together in inland gardens. Give it a slow, deep soak, mulch the root zone, and add afternoon shade if the leaves face west. If leaves are yellowing rather than browning, look at overwatering or alkaline soil instead of thirst.