How often to water quaking grass in California
In July in the Central Valley, established quaking grass needs about 0.8 gallons a week for a plant 2 feet across. Quaking grass is a cool-season perennial grass that forms a neat, semi-evergreen tuft of narrow leaves. From late spring into summer, slender stems carry nodding, heart-shaped, purple-tinted flowerheads that shiver in the breeze and age to tan. It wants sun and well-drained soil and needs little water once established.
How often to water quaking grass, 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: the plant’s WUCOLS rating times your city’s climate for the month, over the area the plant covers. Skip a watering after a good soaking rain.
How to tell it needs water
- Soil dry 3 inches down at the edge of a young clump in spring signals that it needs a soak
- Leaf tips browning and the tuft thinning in summer heat can be the normal slowdown of a cool-season grass, so check the soil first
- Flowerheads fading to tan in summer are normal ripening, not drought
- A flattened, yellowing tuft with a soft base in soggy soil points to poor drainage, since it needs well-drained ground
How to water it
- Water at the base of the clump with drip or a soaker line rather than overhead
- Soak the root zone about a foot deep, then let the top few inches dry well before the next soak
- Plant in full sun or light shade in any well-drained soil, avoiding low spots that stay wet in winter
- Cut the flowerheads back in late summer to encourage fresh growth, then water only if the soil is dry
- Extend the watered strip slowly as the clump widens from its short rhizomes
Through the seasons
A new quaking grass clump needs regular moisture through its first growing season while roots settle. Established clumps need little water. As a cool-season grass, it grows mainly in the cool months, flowers from late spring into summer, and slows in summer heat. Winter rain covers the cool months on the coast and in the Central Valley. Give an occasional deep soak in a long dry spring or summer. WUCOLS rates quaking grass low water across its four rated zones: the north-central coast, the Central Valley, the south coast and South Inland. WUCOLS has not evaluated it for the high desert or the low desert.
In pots
Quaking grass suits a pot, where its nodding flowerheads sit near eye level. Use a free-draining mix and check it an inch or two down every few days in warm weather. Water until it drains through the holes, then pour off the saucer. In summer heat the clump slows down, so let the mix dry a little more between soakings. Over winter, rain may keep an outdoor pot moist, so check before adding water.
- A year
- 6.84 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Quaking Grass: 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 | 0.16 | 0.31 | 0.31 | – | – |
| Feb | 0.21 | 0.26 | 0.32 | 0.35 | – | – |
| Mar | 0.35 | 0.43 | 0.46 | 0.52 | – | – |
| Apr | 0.47 | 0.61 | 0.56 | 0.64 | – | – |
| May | 0.58 | 0.83 | 0.64 | 0.78 | – | – |
| Jun | 0.64 | 0.99 | 0.69 | 0.92 | – | – |
| Jul | 0.64 | 1.07 | 0.79 | 1 | – | – |
| Aug | 0.6 | 0.95 | 0.74 | 0.93 | – | – |
| Sep | 0.5 | 0.72 | 0.6 | 0.74 | – | – |
| Oct | 0.35 | 0.47 | 0.46 | 0.53 | – | – |
| Nov | 0.19 | 0.22 | 0.33 | 0.36 | – | – |
| Dec | 0.12 | 0.14 | 0.26 | 0.27 | – | – |
| Year | 4.8 | 6.84 | 6.2 | 7.37 | – | – |
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 6
Rated low water in the Central Valley, like quaking grass. Plants that drink alike can share one valve and one schedule.
Tufted HairgrassDeschampsia cespitosa and cvs.low water, Central Valley1.07 gal/sq ft in July
June GrassKoeleria macrantha (cristata)low water, Central Valley1.07 gal/sq ft in July
False Esparto GrassLygeum spartumlow water, Central Valley1.07 gal/sq ft in July
Blue FescueFestuca glauca ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Baltic RushJuncus balticuslow water, Central Valley1.07 gal/sq ft in July
Giant Needle GrassStipa gigantealow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes quaking 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 much should I water quaking grass in summer?
In July, established quaking grass needs about 0.8 gallons in the Central Valley, 0.6 gallons on the south coast and 0.7 gallons in the South Inland zone each week, for a plant 2 feet across. Water deeply and let the top of the soil dry before the next watering. Skip a watering after a soaking rain.
How much water does quaking grass need per day?
In July in the Central Valley, established quaking grass needs about 0.1 gallons a day for a plant 2 feet across and about 0.4 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 quaking grass change across California?
Yes. WUCOLS rates quaking grass separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, low water in the South Coastal zone, low water 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 should I cut back quaking grass?
No pruning is required, but cutting the flowerheads back in late summer encourages new growth. Leave the leafy tuft in place. Water the clump once afterward if the soil is dry.
Is quaking grass good for dried flowers?
Yes. The nodding, heart-shaped flowerheads are useful in dried arrangements. Cut the stems as the heads turn buff.
Does quaking grass spread?
It forms a clump that spreads slowly by short rhizomes, and it can also come up from seed. Pull unwanted seedlings while they are small.
Why is my quaking grass brown in summer?
As a cool-season grass it slows in summer heat, and its flowerheads age to tan as they ripen. Some browning is normal. Check the soil a few inches down, and soak only if it is dry.
Can quaking grass grow in part shade?
It grows best in full sun but tolerates part shade. Soil in shade dries more slowly, so check it before watering.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Briza media, 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