WateringTimesWatering plan, $19
Mentha spp. (CA native and non-native spp.), WUCOLS IV

How often to water mint in California

In July in the Central Valley, established mint in loam needs a deep watering about every 8 days: about 2.2 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Mint covers a group of aromatic perennials, from garden spearmint and peppermint to California's native field mint. Square stems spread fast by runners and rhizomes, rooting wherever they touch moist ground. Most mints come from damp fields and stream edges, and they grow lush with steady moisture but struggle in dry soil.

Ground coverPerennialCalifornia nativeRated for 6 of 6 zones

How often to water mint, 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 mint 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 an inch or two down in a mint bed signals that it needs water, since mint wilts quickly in dry soil
  • Leaves drooping by midday in summer heat point to soil that has dried too far
  • Orange or brown powdery spots under the leaves point to rust, a common mint disease, not thirst
  • Yellow lower leaves and blackened stem bases in soggy, poorly drained soil can signal root trouble
  • Runners appearing in nearby beds mean the planting needs containment, not more water

How to water it

  • Water at the soil line rather than overhead, which helps limit rust and leaf spot
  • Soak the top 8 to 12 inches of soil, then water again when the top inch dries
  • Grow it in a container, a raised bed or behind a buried barrier, which also keeps the water where you want it
  • Give it organically rich, moist but well-drained soil in sun or part shade
  • Shear plants after flowering, then water if the soil is dry to push fresh leafy growth

Through the seasons

A new mint planting needs steady moisture while its runners root in. Established beds grow fast from spring through summer and want regular water, since mint does poorly in dry soil. Flowers come in late summer, and shearing afterward brings fresh leaves. Growth slows in winter, when rain usually covers its needs on the coast and in the Central Valley. WUCOLS rates mint low water on the north-central coast. In the Central Valley, on the south coast and in South Inland it rates moderate water. The high desert and the low desert share that moderate water rating.

In pots

A pot is the easiest home for mint, since it keeps the runners from escaping. Use a wide container and rich, well-drained mix. Check the mix an inch down daily in summer heat, because a root-packed pot of mint dries fast, and water until it drains through. Empty the saucer so the mix does not stay soggy. Divide and repot the clump in spring once it fills the pot.

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

Mint: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.40.780.780.740.78
Feb0.210.650.810.870.930.93
Mar0.351.091.151.31.461.52
Apr0.471.521.41.611.891.95
May0.582.081.611.952.392.45
Jun0.642.481.742.292.852.79
Jul0.642.671.982.513.042.85
Aug0.62.391.862.332.792.6
Sep0.51.81.491.862.142.08
Oct0.351.181.151.331.461.49
Nov0.190.560.840.90.930.96
Dec0.120.340.650.680.650.68
Year4.817.1115.518.4121.2721.08

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 mint. Plants that drink alike can share one valve and one schedule.

Similar plants that need less water 16

Rated lower than mint 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 mint, 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 mint in summer?

In July, established mint 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 mint need per day?

In July in the Central Valley, established mint 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 mint change across California?

Yes. WUCOLS rates mint separately for each of the six California climate zones: low 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.

How do I stop mint from spreading?

Grow it in a pot, a raised bed or behind a soil barrier sunk deep enough to stop the rhizomes. Its stems also root wherever they touch moist ground, so trim runners that flop over the edge. Pull strays promptly.

Why does my mint have rust spots?

Rust and leaf spot are the common fungal diseases of mint. Water at the soil rather than over the leaves, cut out spotted stems and give the plants room for air. Rust does not mean the plant is thirsty.

Should I cut back mint after it flowers?

Yes. Shearing off the flower spikes after bloom stimulates fresh leafy growth. Water the bed afterward if the soil is dry so the new shoots come quickly.

Is there a California native mint?

Yes. Field mint grows wild across much of North America, including California, and Mentha canadensis grows in damp places from northern Canada to Mexico. Both like moist soil, just as garden mints do.

Is mint safe for pets?

Mint is listed as a possible problem plant for cats, dogs and horses. Keep pets from grazing on it, especially indoors where a potted mint is within reach.

More plant watering guides

Sources