How often to water weeping bottlebrush in California
In July in the Central Valley, established weeping bottlebrush in loam needs a deep watering about every 20 days: about 55 gallons each time under a 10 foot canopy, about 19 gallons a week. Weeping bottlebrush is a fast-growing Australian evergreen, a large shrub or small tree with long, hanging branches and bright red, bristly flower spikes. In the wild it grows along creeks, yet California gardens have long grown it in drier spots. Young plants need regular deep soaks. Established plants are fairly drought tolerant, though desert heat calls for more water.
How often to water weeping bottlebrush, month by month
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.
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.
How to tell it needs water
- Soil dry 4 inches down at the edge of a young bottlebrush's root ball means it is time for a deep soak
- The branches hang by nature, so judge thirst by limp, soft shoot tips over dry soil rather than by the weeping form
- Pale yellow leaves over soil that stays wet point to too much water, a known problem for the dwarf Little John
- Small crusty bumps on twigs and leaves point to scale insects, a pest of this plant rather than a watering fault
- Leaf drop after a hard freeze is cold damage, not thirst, so wait for new growth before changing the watering
How to water it
- Water a young weeping bottlebrush over its root ball and a band of soil beyond it, then widen that band as the crown spreads
- Soak slowly until water reaches about 18 inches down, then let the top few inches dry before the next soak
- Move drip emitters out toward the edge of the branches as the plant grows, keeping water off the trunk
- Plant in full sun or part shade, in almost any soil that drains, and avoid low spots where water stands
Through the seasons
Give a new weeping bottlebrush deep soakings through its first summer or two, widening the wet area as roots spread. After that it is fairly drought tolerant. This evergreen flowers mainly from spring into fall, with scattered spikes at other times, so summer soil checks matter most. WUCOLS rates it low water on the north-central coast, in the Central Valley, on the south coast and in South Inland. On the coast and in the Central Valley, winter rain covers the cool months. It rates moderate water in the high desert and the low desert. There, check the soil in dry winter spells, and protect young plants from hard frost.
In pots
Weeping bottlebrush grows into a large shrub or small tree, so only a young plant or the dwarf Little John suits a pot for long. Little John forms a dense, rounded mound a few feet tall. Use a large container with open drainage holes. Check the mix 2 inches down every few days in summer heat, and daily in desert heat waves. Water until it drains from the holes, then empty the saucer, since soggy mix can turn the leaves yellow. In winter, let the mix dry a little more between waterings.
- A year
- 6.84 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Weeping Bottlebrush: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.15 | 0.16 | 0.31 | 0.31 | 0.74 | 0.78 |
| Feb | 0.21 | 0.26 | 0.32 | 0.35 | 0.93 | 0.93 |
| Mar | 0.35 | 0.43 | 0.46 | 0.52 | 1.46 | 1.52 |
| Apr | 0.47 | 0.61 | 0.56 | 0.64 | 1.89 | 1.95 |
| May | 0.58 | 0.83 | 0.64 | 0.78 | 2.39 | 2.45 |
| Jun | 0.64 | 0.99 | 0.69 | 0.92 | 2.85 | 2.79 |
| Jul | 0.64 | 1.07 | 0.79 | 1 | 3.04 | 2.85 |
| Aug | 0.6 | 0.95 | 0.74 | 0.93 | 2.79 | 2.6 |
| Sep | 0.5 | 0.72 | 0.6 | 0.74 | 2.14 | 2.08 |
| Oct | 0.35 | 0.47 | 0.46 | 0.53 | 1.46 | 1.49 |
| Nov | 0.19 | 0.22 | 0.33 | 0.36 | 0.93 | 0.96 |
| Dec | 0.12 | 0.14 | 0.26 | 0.27 | 0.65 | 0.68 |
| Year | 4.8 | 6.84 | 6.2 | 7.37 | 21.27 | 21.08 |
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 low water in the Central Valley, like weeping bottlebrush. Plants that drink alike can share one valve and one schedule.
Olive TreesOlea europaea ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Fig TreesFicus carica ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Crape MyrtleLagerstroemia spp., hybrids & cvs.low water, Central Valley1.07 gal/sq ft in July
AloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Pomegranate TreesPunica granatumlow water, Central Valley1.07 gal/sq ft in July
EucalyptusEucalyptus polyanthemoslow water, Central Valley1.07 gal/sq ft in July
Pine TreesPinus canariensislow water, Central Valley1.07 gal/sq ft in July
JunipersJuniperus spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Texas Red OakQuercus buckleyilow water, Central Valley1.07 gal/sq ft in July
Portuguese OakQuercus faginealow water, Central Valley1.07 gal/sq ft in July
Soapbark TreeQuillaja saponarialow water, Central Valley1.07 gal/sq ft in July
Necklace TreeSophora affinislow water, Central Valley1.07 gal/sq ft in July
Bailey AcaciaAcacia baileyanalow water, Central Valley1.07 gal/sq ft in July
Silver WattleAcacia dealbatalow water, Central Valley1.07 gal/sq ft in July
Green WattleAcacia decurrenslow water, Central Valley1.07 gal/sq ft in July
Sydney Golden WattleAcacia longifolialow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes weeping bottlebrush, 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 weeping bottlebrush in summer?
In July, established weeping bottlebrush in loam needs a deep watering about every 20 days in the Central Valley, about every 27 days on the south coast and about every 22 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 weeping bottlebrush need per day?
In July in the Central Valley, established weeping bottlebrush needs about 2.7 gallons a day under a 10 foot canopy and about 11 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 weeping bottlebrush change across California?
Yes. WUCOLS rates weeping bottlebrush separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, low water in the South Coastal zone, low water in the South Inland zone, moderate water in the High and Intermediate Desert zone, moderate water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
Is weeping bottlebrush a Callistemon or a Melaleuca?
Both names are in use. In 2006 a botanist moved nearly all bottlebrushes into Melaleuca, so this plant is now Melaleuca viminalis. Many nurseries still sell it as Callistemon viminalis.
How big does weeping bottlebrush get?
The species usually reaches 15 to 20 feet tall and about 15 feet wide, and it can grow taller. Slim is a narrow form, 8 to 12 feet tall and 4 to 6 feet wide. Little John starts as a mound 3 to 5 feet tall, and older plants can grow larger.
Can weeping bottlebrush take frost?
Its common selections are rated hardy to about 20 to 25 degrees F. A harder freeze can strip the leaves. Little John is reported to regrow after losing its leaves in the teens, but plants in cold inland spots need protection in a hard freeze.
Does weeping bottlebrush attract hummingbirds?
Yes. The red flower spikes make nectar that draws hummingbirds and bees. Bloom peaks from spring into fall, depending on the selection, and scattered spikes appear at other times.
When should I prune weeping bottlebrush?
Prune right after a flush of flowers and cut off most of the spent spikes. The branch keeps growing past each spike, which later holds small woody seed capsules. Light pruning then keeps the weeping shape tidy.
Is weeping bottlebrush safe for pets?
It is listed as non-toxic for cats, dogs and horses. Bees visit the flowers, so keep it back from paths and play areas.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Callistemon viminalis & ssp. & cvs., the University of California survey California agencies use for landscape plan reviewRead August 23, 2026 on wucols.ucdavis.edu
- Model Water Efficient Landscape Ordinance, adopted text and appendices, effective 2025-01-02 · monthly reference evapotranspiration per city, Appendix CRead August 23, 2026 on water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/Water-Use-And-Efficiency/MWELO-Rulemaking/Final-MWELO-Text-and-Appendices_20250103.pdf
- UC Statewide IPM Program, irrigation scheduling using evapotranspirationRead September 30, 2026 on ipm.ucanr.edu/PMG/GARDEN/ENVIRON/evap.html
- Shaw and Pittenger, Landscape Irrigation System Evaluation and Management, UC Cooperative Extension, 2009Read September 30, 2026 on ucanr.edu/sites/default/files/2013-02/160836.pdf
- Pittenger, Water Management in Gardens and Landscapes, UC Riverside, 2017Read September 30, 2026 on ucanr.edu/sites/default/files/2017-03/258022.pdf