WateringTimesWatering plan, $19
Cuphea hyssopifolia, WUCOLS IV

How often to water false heather in California

In July in the Central Valley, established false heather in loam needs a deep watering about every 8 days: about 8.8 gallons each time for a plant 4 feet across, about 7.6 gallons a week. False heather, also called Mexican heather, is a small, dense evergreen shrub from Mexico, Guatemala and Honduras, up to 2 feet tall and wide. Tiny glossy leaves line its many stems, and small lavender flowers bloom along them until frost. It is not a true heather. It handles high summer heat and some drought but grows best with regular moisture.

ShrubRated for 6 of 6 zones

How often to water false heather, 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 false heather 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

  • Soil dry 2 inches down around the plant in summer means false heather needs water
  • Leaves drooping and flowers thinning in heat point to a dry root zone
  • Stems dying back after a frost point to cold damage
  • Yellowing leaves in soggy soil point to poor drainage

How to water it

  • Water regularly, letting only the top inch or two dry
  • Plant in full sun in well-drained soil
  • Use it as edging, low hedging or in containers
  • Replant every year or two, since young plants look best
  • Mulch to hold moisture in hot inland gardens

Through the seasons

Water new plants regularly until they fill out. Established plants want steady, moderate moisture through the long bloom season, which runs until frost. It is moderately salt tolerant and stands up to summer heat. Many gardeners replant every year or two, since young plants look best. WUCOLS rates false heather moderate water on the north-central coast and in the Central Valley. The south coast, South Inland, the high desert and the low desert carry the same moderate water rating.

In pots

False heather is a natural for pots, window boxes and patio planters, where its tiny lavender flowers last for months. Use a well-drained mix. Water when the top inch dries, until it drains through. In summer, small pots may need water every day. Empty the saucer. In cold areas, move the pot indoors to a warm, sunny spot for winter, and water only when the mix dries.

1 Your climate zone six WUCOLS zones, each from its own reference city
2.67gal per sq ft in JulyModerate water use in the Central Valley zone
A year
17.11 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.761.52.33.00.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.761.52.33.00.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

False Heather: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.780.740.78
Feb0.530.650.810.870.930.93
Mar0.871.091.151.31.461.52
Apr1.181.521.41.611.891.95
May1.462.081.611.952.392.45
Jun1.612.481.742.292.852.79
Jul1.612.671.982.513.042.85
Aug1.492.391.862.332.792.6
Sep1.241.81.491.862.142.08
Oct0.871.181.151.331.461.49
Nov0.470.560.840.90.930.96
Dec0.310.340.650.680.650.68
Year1217.1115.518.4121.2721.08

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 moderate water in the Central Valley, like false heather. Plants that drink alike can share one valve and one schedule.

Similar plants that need less water 16

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

Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes false heather, 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 false heather in summer?

In July, established false heather in loam needs a deep watering about every 8 days in the Central Valley, about every 11 days on the south coast and about every 9 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 false heather need per day?

In July in the Central Valley, established false heather needs about 1.1 gallons a day for a plant 4 feet across and about 4.3 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 false heather change across California?

Yes. WUCOLS rates false heather 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, moderate 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 false heather a real heather?

No, it resembles heather but belongs to a different family. That is why it is called false heather. It is also called Mexican heather.

Can false heather take heat?

Yes, it withstands high summer heat and some drought. It still grows best with regular moisture. Mulch helps.

When does false heather bloom?

Small lavender flowers bloom profusely along the stems until frost. Regular water keeps it flowering. Light trims keep it neat.

Is false heather invasive?

It has naturalized and become weedy in Hawaii. In gardens it stays small. Remove seedlings if they appear.

Can false heather grow in pots?

Yes, it is often grown as a container plant. It can come indoors to a warm, sunny spot. Check pots daily in summer.

More plant watering guides

Sources