How often to water oyama magnolia in California
In July in the Central Valley, established oyama magnolia in loam needs a deep watering about every 8 days: about 55 gallons each time under a 10 foot canopy, about 47 gallons a week. Oyama magnolia is a large deciduous shrub or small tree, about 26 feet tall and wide. Its nodding, fragrant, pure white flowers are centered on red stamens. Bloom starts in spring and continues off and on through summer, followed by pink fruits that split to show red seeds. It wants consistent moisture, rich acidic soil and morning sun with afternoon shade.
How often to water oyama magnolia, 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 2 to 3 inches down under the mulch in summer signals oyama magnolia needs water
- Leaves drooping and edges browning in afternoon sun can indicate thirst or too much heat
- Flower buds dropping before opening can follow a dry root zone
- Yellowing leaves with soggy soil point to poor drainage
How to water it
- Water the root zone under the canopy with drip or a soaker
- Soak about a foot down, then water again as the top couple of inches dry
- Plant in moist, rich, slightly acidic, well-drained loam
- Site it with morning sun and afternoon shade, sheltered from strong wind
- Mulch generously to keep soil cool and evenly moist
Through the seasons
Keep a new oyama magnolia evenly moist through its first summers. Established plants still need consistent moisture, since they do not tolerate dry, poor soil or hot sun. It is deciduous, with leaves turning golden yellow in fall. A late frost can damage spring flowers. WUCOLS rates oyama magnolia moderate water on the north-central coast, in the Central Valley and on the south coast. WUCOLS has not evaluated it for South Inland, the high desert or the low desert.
In pots
A young oyama magnolia can grow for some years in a large container in a sheltered, partly shaded spot. Use rich, acidic, well-drained mix and keep it evenly moist, watering when the top inch dries. In summer, check every day or two. Let it drain and empty the saucer. Keep the pot out of wind, since the branches are brittle. After leaf drop, water lightly through winter and shield the pot from hard frost.
- A year
- 17.11 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Oyama Magnolia: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.37 | 0.4 | 0.78 | – | – | – |
| Feb | 0.53 | 0.65 | 0.81 | – | – | – |
| Mar | 0.87 | 1.09 | 1.15 | – | – | – |
| Apr | 1.18 | 1.52 | 1.4 | – | – | – |
| May | 1.46 | 2.08 | 1.61 | – | – | – |
| Jun | 1.61 | 2.48 | 1.74 | – | – | – |
| Jul | 1.61 | 2.67 | 1.98 | – | – | – |
| Aug | 1.49 | 2.39 | 1.86 | – | – | – |
| Sep | 1.24 | 1.8 | 1.49 | – | – | – |
| Oct | 0.87 | 1.18 | 1.15 | – | – | – |
| Nov | 0.47 | 0.56 | 0.84 | – | – | – |
| Dec | 0.31 | 0.34 | 0.65 | – | – | – |
| Year | 12 | 17.11 | 15.5 | – | – | – |
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 moderate water in the Central Valley, like oyama magnolia. Plants that drink alike can share one valve and one schedule.
RosesRosa hybrids..bushmoderate water, Central Valley2.67 gal/sq ft in July
Citrus TreesCitrus spp.moderate water, Central Valley2.67 gal/sq ft in July
AzaleasRhododendron spp. (CA native and non-native spp.)moderate water, Central Valley2.67 gal/sq ft in July
CamelliasCamellia japonica (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in July
GardeniasGardenia spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in July
Japanese MapleAcer palmatummoderate water, Central Valley2.67 gal/sq ft in July
Avocado TreesPersea americanamoderate water, Central Valley2.67 gal/sq ft in July
Bird of ParadiseStrelitzia reginae (shade in desert)moderate water, Central Valley2.67 gal/sq ft in July
HibiscusHibiscus rosa-sinensismoderate water, Central Valley2.67 gal/sq ft in July
Magnolia TreesMagnolia grandiflora ssp. & cvs.moderate water, Central Valley2.67 gal/sq ft in July
Palm TreesSyagrus romanzoffiana (Arecastrum romanzoffianum)moderate water, Central Valley2.67 gal/sq ft in July
Sago PalmCycas revolutamoderate water, Central Valley2.67 gal/sq ft in July
Star JasmineTrachelospermum jasminoides and cvs.moderate water, Central Valley2.67 gal/sq ft in July
Apple TreesMalus spp. (edible) e.g, 'Anna' (low chill variety for low desert)moderate water, Central Valley2.67 gal/sq ft in July
Peach TreesPrunus spp. ediblemoderate water, Central Valley2.67 gal/sq ft in July
Persimmon TreesDiospyros kakimoderate water, Central Valley2.67 gal/sq ft in JulySimilar plants that need less water 16
Rated lower than oyama magnolia in the Central Valley. Worth a look for a new bed or a lawn replacement.
LavenderLavandula spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
RosemaryRosmarinus officinalislow water, Central Valley1.07 gal/sq ft in July
BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
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
LantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in July
AloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SucculentsEcheveria 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
Russian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes oyama magnolia, 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 oyama magnolia in summer?
In July, established oyama magnolia in loam needs a deep watering about every 8 days in the Central Valley and about every 11 days on the south coast. 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 oyama magnolia need per day?
In July in the Central Valley, established oyama magnolia needs about 6.8 gallons a day under a 10 foot canopy and about 27 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 oyama magnolia change across California?
Yes. WUCOLS rates oyama magnolia separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, moderate water in the Central Valley zone, moderate water in the South Coastal zone, not evaluated in the South Inland zone, not evaluated in the High and Intermediate Desert zone, not evaluated in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
Can oyama magnolia take full sun?
Not in hot summer climates. Give it morning sun and afternoon shade. Full sun inland scorches leaves and dries the soil.
When does oyama magnolia bloom?
It blooms in spring and keeps flowering here and there through summer. The fragrant white flowers have red stamens. A late frost can damage the first flowers.
Why are my magnolia branches breaking?
Its branches can be brittle. Plant it where it is sheltered from strong wind. Prune damaged limbs cleanly.
What are the pink pods on my magnolia?
They are the fruits, which split in fall to show orange to red seeds. They are ornamental and last into fall.
Does oyama magnolia have pest problems?
It has no known serious pests or diseases. Most problems come from dry soil or too much sun. Keep moisture steady.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Magnolia sieboldii, 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