WateringTimesWatering plan, $19
Banksia ericifolia, WUCOLS IV

How often to water heath-leafed banksia in California

In July on the north-central coast, established heath-leafed banksia in loam needs a deep soak only about once a month or less: about 8.8 gallons each time for a plant 4 feet across. Heath-leafed banksia is a fast-growing evergreen shrub from sandy coastal soils of southeastern Australia, 6 to 12 feet tall and wide. Its short, needlelike leaves are dark green above. In fall and winter, tall, candle-shaped spikes of tiny red-orange flowers rise along the branches. It wants sun, excellent drainage and only occasional water once established.

PerennialShrubRated for 2 of 6 zones

How often to water heath-leafed banksia, month by month

Your city
Plant width
4 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 heath-leafed banksia 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 the plant covers, 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 plant width

A shrub with its width marked from one side to the other and the circle under it shaded blue

Measure across the plant, from the tips of the leaves on one side to the tips on the other.

Water the whole area the plant covers, shown in blue. The gallons here cover that area.

A wider plant means more gallons each watering, not more waterings. While it is young, measure again each spring.

How to tell it needs water

  • New shoots on heath-leafed banksia wilting while the soil is dry several inches down mean it needs water
  • Yellowing new leaves in alkaline soil can point to iron deficiency, not thirst
  • A plant that stays limp in soggy soil points to poor drainage
  • Firm, dark foliage through a dry summer means the plant has enough water

How to water it

  • Water deeply around the root zone, then let the soil dry well before the next soak
  • Plant in full sun in sandy, well-drained soil with good air circulation
  • Cut back to rare summer soaks once it is established
  • Mulch lightly with coarse material, keeping it off the stems
  • Widen the watered area as the shrub fills its wide spread

Through the seasons

Water a new plant through its first dry season so roots spread through the soil. Once established, it needs little water and handles dry summers well. It is evergreen, and the flower spikes come in fall and winter as rain usually returns. Avoid frequent shallow watering, which keeps roots near the surface. WUCOLS rates heath-leafed banksia low water on the north-central coast and on the south coast. WUCOLS marks it as not suited to the Central Valley. WUCOLS has not evaluated it for South Inland, the high desert or the low desert.

In pots

Compact heath-leafed banksia forms can grow in a large container for a few years. Use a coarse, well-drained mix. Water when the top couple of inches are dry, until it drains out the base. In summer, check every few days. Keep the saucer empty so roots do not sit wet. In winter, water only when the mix dries, and move the pot to shelter if a hard frost is due.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Heath-Leafed Banksia for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Heath-Leafed Banksia as not suited to this region for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Heath-Leafed Banksia: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.15–0.31–––
Feb0.21–0.32–––
Mar0.35–0.46–––
Apr0.47–0.56–––
May0.58–0.64–––
Jun0.64–0.69–––
Jul0.64–0.79–––
Aug0.6–0.74–––
Sep0.5–0.6–––
Oct0.35–0.46–––
Nov0.19–0.33–––
Dec0.12–0.26–––
Year4.8–6.2–––

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 not suited to this region in the Central Valley, like heath-leafed banksia. Plants that drink alike can share one valve and one schedule.

Chenille PlantAcalypha hispidanot rated, Central Valleyno Central Valley ratingCopperleafAcalypha wilkesiananot rated, Central Valleyno Central Valley ratingDesert RoseAdenium obesumnot rated, Central Valleyno Central Valley ratingYellow Bell BauhiniaBauhinia tomentosanot rated, Central Valleyno Central Valley ratingMagic FlowerCantua buxifolianot rated, Central Valleyno Central Valley ratingClustered Fishtail PalmCaryota mitisnot rated, Central Valleyno Central Valley ratingHawaiian TiCordyline fruticosa (Cordyline terminalis)not rated, Central Valleyno Central Valley ratingFilbertCorylus maximanot rated, Central Valleyno Central Valley ratingPoinsettiaEuphorbia pulcherrimanot rated, Central Valleyno Central Valley ratingWeeping Chinese BanyanFicus benjaminanot rated, Central Valleyno Central Valley ratingRubber PlantFicus elasticanot rated, Central Valleyno Central Valley ratingFranklin TreeFranklinia alatamaha (Gordonia alatamaha)not rated, Central Valleyno Central Valley ratingKahili GingerHedychium gardnerianumnot rated, Central Valleyno Central Valley ratingJungle GeraniumIxora coccineanot rated, Central Valleyno Central Valley ratingAlpine ToadflaxLinaria alpinanot rated, Central Valleyno Central Valley ratingSkunk CabbageLysichiton americanusnot rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes heath-leafed banksia, 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 heath-leafed banksia need per day?

In July on the north-central coast, established heath-leafed banksia needs about 0.3 gallons a day for a plant 4 feet across and about 1.0 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.

Does watering for heath-leafed banksia change across California?

Yes. WUCOLS rates heath-leafed banksia 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, low 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.

When does heath-leafed banksia bloom?

Its red-orange spikes appear in fall and winter. Some selections keep blooming into spring and summer. The spikes look like tall candles on the branches.

Is heath-leafed banksia good near the beach?

Yes, it accepts salt spray and suits windy seaside gardens. It is native to coastal areas. Give it sun and fast drainage.

How big does heath-leafed banksia get?

It grows fast to 6 to 12 feet tall and wide. Compact forms stay 4 to 6 feet tall. Use the larger form as a screen.

Why are my banksia leaves yellow?

In alkaline soil, yellow new leaves can mean iron deficiency. Check drainage too, since soggy soil stresses roots. Water less if the soil stays wet.

Where does the name banksia come from?

The genus honors Sir Joseph Banks. He collected the first banksia specimens in Australia in 1770, including this species. The species name compares its leaves to heath.

More plant watering guides

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Sources