WateringTimesWatering plan, $19
Sequoia sempervirens, WUCOLS IV

How often to water coast redwood in California

In July in the Central Valley, established coast redwood in loam needs a deep watering about every 5 days: about 55 gallons each time under a 10 foot canopy, about 76 gallons a week. Coast redwood is a towering evergreen conifer with shallow, wide-spreading roots built to catch fog drip in its native coastal belt. Away from that fog, a landscape tree depends on irrigation to replace moisture the air no longer supplies. It struggles through prolonged heat and dry soil, especially in its first years in the ground.

TreeCalifornia nativeRated for 3 of 6 zones

How often to water coast redwood, month by month

Your city
Canopy width
10 ft
Your soil

Type your city above and the days between waterings and the gallons appear here, worked out from your city's climate table. Or read the figures by climate zone further down.

Every month, on your water days. The personal plan prints this for coast redwood and the rest of your yard, on the days your water supplier allows.Get the plan for $19

How this is worked out: established roots fill the top 1.5 feet of soil, and you water again when that soil has dried halfway. Loam soil holds about 1.5 inches of water per foot. Water the whole area under the branches, and skip a watering after a good soaking rain.

Which soil do you have?

Dig down a few inches, take a handful of moist soil and squeeze it.

  • Sandy: gritty, falls apart when you open your hand, will not form a ball.
  • Loam: forms a soft ball that crumbles when you poke it.
  • Clay: forms a firm, sticky ball and squeezes out into a ribbon between thumb and finger.

Still not sure? Pick loam. Most garden beds sit between sand and clay.

How to measure canopy width

A tree with its canopy width marked across the widest branches and the circle under it shaded blue

Measure across the branches, from the tips of the outer leaves on one side to the tips on the other. A tape works, or pace it out.

Water the whole circle under the branches, shown in blue. The gallons here cover that circle.

A wider canopy means more gallons each watering, not more waterings. While the tree is young, measure again each spring.

How to tell it needs water

  • Dry soil a foot down across the wide root spread signals a young coast redwood needs a deep soak
  • Foliage turning dull gray or browning at the needle tips during summer heat can indicate the shallow roots have dried out
  • Stalled height growth through a long hot stretch often traces back to a dry root zone on a tree still establishing
  • Yellowing foliage paired with soft, dark bark at the trunk base in soggy ground can point to root rot from overwatering
  • A redwood planted inland needing more frequent soil checks than one near the coast reflects the missing fog, not a problem with the tree

How to water it

  • Water the full spread of surface roots out beyond the branch tips rather than close against the trunk
  • Soak the root zone a foot or more deep, then let the top few inches dry before watering again
  • Use drip emitters or a soaker hose laid in a wide ring instead of a single point at the trunk
  • Keep a thick layer of wood chip mulch over the root zone to slow evaporation and moderate soil temperature
  • Move emitters outward each year as the canopy and root spread grow wider

Through the seasons

Keep a newly planted coast redwood evenly moist through its first several summers while its shallow roots establish. Established trees still need steady moisture: unlike their native groves, most California yards offer no summer fog to replace what the foliage loses. This conifer stays evergreen year round, with water mattering most from late spring through fall. Winter rain can cover the cool months on the north-central coast and in the Central Valley. WUCOLS rates coast redwood high water on the north-central coast, in the Central Valley and in South Inland. WUCOLS marks it as not suited to the south coast, the high desert and the low desert.

In pots

A young coast redwood can spend a few years in a large container before its wide-spreading roots need open ground. Check the mix several inches down often in summer heat, since potting mix dries faster than garden soil and this tree has little drought tolerance to fall back on. Water until it drains through the holes, then empty the saucer. Give it some shade from hot inland sun rather than full exposure. In winter, water less often as growth slows, but never let the root ball dry out completely.

1 Your climate zone six WUCOLS zones, each from its own reference city
4.27gal per sq ft in JulyHigh water use in the Central Valley zone
A year
27.38 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
1.12.13.24.30.64JAN1.04FEB1.74MAR2.43APR3.32MAY3.97JUN4.27JUL3.82AUG2.88SEP1.88OCT0.89NOV0.55DEC1.12.13.24.30.64JFM2.43AMJ4.27JAS1.88OND
Gallons per square foot per month, Central Valley. Peak 4.27 in Jul, 27.38 a year.

Monthly water need by climate zone

Coast Redwood: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.60.64–1.24––
Feb0.841.04–1.39––
Mar1.391.74–2.08––
Apr1.882.43–2.58––
May2.333.32–3.12––
Jun2.583.97–3.67––
Jul2.584.27–4.02––
Aug2.383.82–3.72––
Sep1.982.88–2.98––
Oct1.391.88–2.13––
Nov0.740.89–1.44––
Dec0.50.55–1.09––
Year19.227.38–29.46––

How this is worked out: the WUCOLS water rating for each zone times that zone’s climate for the month. A dash means WUCOLS does not rate the plant there. The figures are what the plant uses, before sprinkler losses.

Plants with the same water needs 16

Rated high water in the Central Valley, like coast redwood. Plants that drink alike can share one valve and one schedule.

Big Leaf MapleAcer macrophyllumhigh water, Central Valley4.27 gal/sq ft in JulyWhite AlderAlnus rhombifoliahigh water, Central Valley4.27 gal/sq ft in JulyRed AlderAlnus rubra (Alnus oregona)high water, Central Valley4.27 gal/sq ft in JulyRiver BirchBetula nigrahigh water, Central Valley4.27 gal/sq ft in JulyWater BirchBetula occidentalishigh water, Central Valley4.27 gal/sq ft in JulyEuropean White BirchBetula pendulahigh water, Central Valley4.27 gal/sq ft in JulyWhite-Barked Himalayan BirchBetula utilis var. jacquemontiihigh water, Central Valley4.27 gal/sq ft in JulyEuropean BeechFagus sylvaticahigh water, Central Valley4.27 gal/sq ft in JulyBlack CottonwoodPopulus trichocarpa (Populus balsamifera)high water, Central Valley4.27 gal/sq ft in JulyCarolina PoplarPopulus x canadensishigh water, Central Valley4.27 gal/sq ft in JulyWeeping WillowSalix babylonicahigh water, Central Valley4.27 gal/sq ft in JulyPeking WillowSalix matsudanahigh water, Central Valley4.27 gal/sq ft in JulyVine MapleAcer circinatumhigh water, Central Valley4.27 gal/sq ft in JulyHydrangeaHydrangea macrophylla & cvs.high water, Central Valley4.27 gal/sq ft in JulyBlueberriesVaccinium hybrids and cvs (CA native and non- native spp.)high water, Central Valley4.27 gal/sq ft in JulyShell GingerAlpinia zerumbethigh water, Central Valley4.27 gal/sq ft in July

Similar plants that need less water 16

Rated lower than coast redwood in the Central Valley. Worth a look for a new bed or a lawn replacement.

Citrus TreesCitrus spp.moderate water, Central Valley2.67 gal/sq ft in JulyJapanese MapleAcer palmatummoderate water, Central Valley2.67 gal/sq ft in JulyAvocado TreesPersea americanamoderate water, Central Valley2.67 gal/sq ft in JulyMagnolia TreesMagnolia grandiflora ssp. & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyPalm TreesSyagrus romanzoffiana (Arecastrum romanzoffianum)moderate water, Central Valley2.67 gal/sq ft in JulyApple TreesMalus spp. (edible) e.g, 'Anna' (low chill variety for low desert)moderate water, Central Valley2.67 gal/sq ft in JulyPeach TreesPrunus spp. ediblemoderate water, Central Valley2.67 gal/sq ft in JulyPersimmon TreesDiospyros kakimoderate water, Central Valley2.67 gal/sq ft in JulyAmur MapleAcer ginnalamoderate water, Central Valley2.67 gal/sq ft in JulyFernleaf MapleAcer japonicummoderate water, Central Valley2.67 gal/sq ft in JulyBox ElderAcer negundomoderate water, Central Valley2.67 gal/sq ft in JulyNorway MapleAcer platanoidesmoderate water, Central Valley2.67 gal/sq ft in JulyRed MapleAcer rubrummoderate water, Central Valley2.67 gal/sq ft in JulyChinese MapleAcer truncatummoderate water, Central Valley2.67 gal/sq ft in JulyRed BuckeyeAesculus paviamoderate water, Central Valley2.67 gal/sq ft in JulyRed HorsechestnutAesculus x carneamoderate water, Central Valley2.67 gal/sq ft in July
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes coast redwood, your sprinkler type and the month, and gives the minutes per water day for that supplier's schedule. Or put it in a zone of the personal watering plan and get all twelve months printed.

Questions people ask

How often should I water coast redwood in summer?

In July, established coast redwood in loam needs a deep watering about every 5 days in the Central Valley 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.

How much water does coast redwood need per day?

In July in the Central Valley, established coast redwood needs about 11 gallons a day under a 10 foot canopy and about 43 gallons a day under a 20 foot canopy. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Does watering for coast redwood change across California?

Yes. WUCOLS rates coast redwood separately for each of the six California climate zones: high water in the North-Central Coastal zone, high water in the Central Valley zone, not suited to this region 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.

Can a coast redwood survive on rainfall alone in California?

Only near the coast, where summer fog adds moisture the roots can use. Inland or in a dry yard, rainfall alone leaves the tree short through summer. Plan on supplemental water for the life of the tree, not just while it establishes.

Why is my redwood lifting the sidewalk or patio?

Coast redwood roots spread wide and shallow, often farther than the branches reach. Keep new trees well back from paving and foundations. Moving water away from hardscape will not redirect roots already growing toward it.

Can I grow coast redwood in a hot inland yard?

It can survive there with consistent irrigation, but prolonged heat and dry soil stress the tree more than its foggy native range does. Expect more frequent checks than a coastal planting needs. Choose a site with some afternoon shade if one is available.

Does mulch help a young redwood more than extra water?

Both matter together. Mulch slows evaporation and keeps the shallow root zone cooler, but it does not replace a missing deep soak. Use mulch to stretch the time between waterings, not to skip them.

Why are the lower branches on my redwood dying back?

Branch dieback and dropping debris are common signs of stress in redwoods grown away from the coast. Check soil moisture at the drip line and across the wide root zone first.

Is coast redwood a good choice for a small yard?

Its wide roots and eventual large size make it a poor fit near foundations, pools or narrow lots. Consider the space the roots will need many years from now before planting one as a specimen tree.

More plant watering guides

Vine MapleHydrangeaBlueberriesBig Leaf MapleJapanese Sweet FlagWhite AlderRed AlderRed Ginger

Sources