How often to water Egyptian star flower in California
In July on the north-central coast, established Egyptian star flower in loam needs a deep watering about every 22 days: about 1.5 gallons each time for a plant 2 feet across, about 0.5 gallons a week. Egyptian star flower, often sold as pentas, is a tropical shrubby plant from East Africa, grown as a perennial where frost is rare and as an annual elsewhere. Clusters of star-shaped flowers in violet to pink bloom from spring into fall, and red kinds draw hummingbirds. It usually stays about 2 feet tall and wide in well-drained, organically rich soil.
How often to water Egyptian star flower, 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 foot 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 the plant covers, and skip a watering after a good soaking rain.
How to tell it needs water
- Soil dry 2 inches down beside the plant tells you Egyptian star flower can be watered
- Leaves drooping in late afternoon heat can indicate the soil has dried too far
- Fewer new flower clusters during a long dry spell can follow a dry root zone
- Fine speckling and webbing under the leaves point to spider mites, not water
How to water it
- Water consistently, letting the soil dry between waterings
- Soak the root zone about 6 inches deep, then let the top couple of inches dry
- Plant in full sun in well-drained, organically rich soil
- Allow some shade if needed, though sun gives more bloom
- Remove faded flower clusters to keep it tidy
Through the seasons
Water new plants consistently while roots establish, letting the soil dry a little between waterings. Established plants have moderate to high drought tolerance, though steady water keeps the flowers coming from spring into fall. Frost ends its season, so it is often replanted each year. WUCOLS rates Egyptian star flower low water on the north-central coast. On the south coast it carries a moderate water rating. WUCOLS marks it as not suited to the Central Valley, the high desert or the low desert, and has not evaluated it for South Inland.
In pots
Egyptian star flower is a popular pot plant for sunny patios. Use a well-drained, rich mix. Water when the top inch or two is dry, until it drains through. A pot in full summer sun may need water every day or two. Empty the saucer. Pinch off spent clusters to keep new ones coming. In winter, keep the pot in a bright, frost-free place and water only when the mix dries.
- A year
- no figure
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
WUCOLS lists Egyptian Star Flower as not suited to this region for the Central Valley zone, so no monthly figure is computed here.
Monthly water need by climate zone
Egyptian Star Flower: 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 | – | 0.78 | – | – | – |
| Feb | 0.21 | – | 0.81 | – | – | – |
| Mar | 0.35 | – | 1.15 | – | – | – |
| Apr | 0.47 | – | 1.4 | – | – | – |
| May | 0.58 | – | 1.61 | – | – | – |
| Jun | 0.64 | – | 1.74 | – | – | – |
| Jul | 0.64 | – | 1.98 | – | – | – |
| Aug | 0.6 | – | 1.86 | – | – | – |
| Sep | 0.5 | – | 1.49 | – | – | – |
| Oct | 0.35 | – | 1.15 | – | – | – |
| Nov | 0.19 | – | 0.84 | – | – | – |
| Dec | 0.12 | – | 0.65 | – | – | – |
| Year | 4.8 | – | 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 10
Rated not suited to this region in the Central Valley, like Egyptian star flower. Plants that drink alike can share one valve and one schedule.
Desert RoseAdenium obesumnot rated, Central Valleyno Central Valley rating
Kahili GingerHedychium gardnerianumnot rated, Central Valleyno Central Valley rating
Alpine ToadflaxLinaria alpinanot rated, Central Valleyno Central Valley rating
Skunk CabbageLysichiton americanusnot rated, Central Valleyno Central Valley rating
Swedish IvyPlectranthus verticillatusnot rated, Central Valleyno Central Valley rating
Solomon's SealPolygonatum odoratum (japonicum)not rated, Central Valleyno Central Valley rating
Painted DaisyTanacetum coccineum (Pyrethrum roseum)not rated, Central Valleyno Central Valley rating
Wandering JewTradescantia fluminensis (SHADE)not rated, Central Valleyno Central Valley rating
Moses-in-the-CradleTradescantia spathacea (Rhoeo spathacea)not rated, Central Valleyno Central Valley rating
Heath-Leafed BanksiaBanksia ericifolianot rated, Central Valleyno Central Valley ratingTurn this into minutes on your water days
Every city page has a calculator that takes Egyptian star flower, 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 much water does Egyptian star flower need per day?
In July on the north-central coast, established Egyptian star flower needs about 0.1 gallons a day for a plant 2 feet across and about 0.3 gallons a day for a plant 4 feet across. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.
Does watering for Egyptian star flower change across California?
Yes. WUCOLS rates Egyptian star flower separately for each of the six California climate zones: low water in the North-Central Coastal zone, not suited to this region in the Central Valley zone, moderate water in the South Coastal zone, not evaluated 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.
Does Egyptian star flower attract hummingbirds?
Red kinds attract hummingbirds. Plant them where you can watch. Steady water keeps it blooming.
Is Egyptian star flower a perennial?
It is perennial where frost is rare. Elsewhere it is grown as an annual or houseplant. Frost damages it.
Does Egyptian star flower need full sun?
Full sun encourages the most bloom. It tolerates some shade. Expect fewer flowers in shade.
Do deer eat Egyptian star flower?
It is seldom damaged by deer. Caterpillars may chew the leaves. Spider mites and aphids also appear.
Can I grow Egyptian star flower from seed?
Yes, it grows easily from seed started indoors 8 to 10 weeks before the last frost. Keep seedlings lightly moist. Plant out after frost.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Pentas lanceolata, 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