WateringTimesWatering plan, $19
Ophiopogon japonicus SHADE in desert, WUCOLS IV

How often to water mondo grass in California

In July in the Central Valley, established mondo grass in loam needs a deep watering about every 5 days: about 1.5 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Mondo grass, or dwarf lilyturf, is an evergreen, grass-like groundcover from Japan, Korea and China that grows 6 to 12 inches tall. It spreads by runners and tuberous roots into a soft mat. Pale lilac summer flowers hide in the leaves, followed by more noticeable blue berries. It is very salt tolerant and resists deer and foot traffic.

PerennialRated for 6 of 6 zones

How often to water mondo grass, month by month

Your city
Plant width
2 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 mondo grass 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 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.

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

  • When the mat lifts easily and the soil beneath is dry a couple of inches down in summer, mondo grass needs water
  • Leaf tips browning and curling in hot sun point to too much sun and dry soil
  • Leaves chewed with ragged edges point to slugs, not water
  • Patches yellowing in soil that stays soggy point to overwatering

How to water it

  • Water deeply, then let the top inch or two dry
  • Plant in shade inland, or in sun along the coast
  • Use moist, well-drained soil
  • Mow or shear it once a year to refresh a lawn-like planting
  • Divide clumps to spread it into new areas

Through the seasons

Water new plantings regularly until runners spread. Established mats want occasional to regular water, more in sun and heat. It stays evergreen, flowers in summer and sets blue berries. WUCOLS adds a note that it needs shade in the desert. WUCOLS rates mondo grass moderate water on the north-central coast and in the Central Valley. The south coast, South Inland, the high desert and the low desert share that moderate water rating, so the same routine works statewide with shade added in the deserts.

In pots

Mondo grass makes a tidy edging in pots and a soft skirt around container trees. Use a moist but well-drained mix. Water when the top inch dries, until it drains through. In summer, check pots every few days. Empty the saucer. Keep pots in shade inland. Divide crowded clumps to start new pots. In winter, water when the mix dries and rain falls short.

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

Mondo Grass: 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 mondo grass. Plants that drink alike can share one valve and one schedule.

Similar plants that need less water 16

Rated lower than mondo grass 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 mondo grass, 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 mondo grass in summer?

In July, established mondo grass in loam needs a deep watering about every 5 days in the Central Valley, about every 7 days on the south coast and about every 6 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 mondo grass need per day?

In July in the Central Valley, established mondo grass needs about 0.3 gallons a day for a plant 2 feet across and about 1.1 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 mondo grass change across California?

Yes. WUCOLS rates mondo grass 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.

Can mondo grass replace a lawn?

Yes, it works as a turf alternative in shady areas and tolerates foot traffic. Mow it once a year. It needs less mowing than a lawn.

Can mondo grass grow in sun?

It takes full sun along the coast but needs shade inland and in the desert. In sun it needs more water. Leaf tips burn in hot sun.

Is mondo grass a true grass?

No, it is a grass-like plant related to asparagus. It stays evergreen. It forms mats by runners.

Is mondo grass good under trees?

Yes, it is ideal around the base of trees where many plants struggle. Water it deeply to compete with tree roots. Mulch helps.

Does mondo grass tolerate salt?

Yes, it is highly salt tolerant. That suits coastal gardens. It also resists deer.

More plant watering guides

Sources