How often to water Korean mint in California
In July in the Central Valley, established Korean mint 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. Korean mint, or wrinkled giant hyssop, is a perennial from the mountains of eastern Asia, where it often grows along stream banks. Spikes of showy purple flowers draw bees, butterflies and hummingbirds, and the leaves have a licorice scent that gives it names like blue licorice. Deer and rabbits tend to leave it alone.
How often to water Korean mint, 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: 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.
How to tell it needs water
- When the soil around Korean mint has dried a few inches down in summer, it is ready for water
- Flower spikes thinning out in a long hot spell can follow dry soil
- Lower leaves yellowing in heavy, soggy soil point to too much water
- Leaves smelling of licorice when brushed is normal, not a sign of stress
How to water it
- Soak the root zone, then let the upper soil dry before watering again
- Plant in full sun in soil that drains well
- Group several plants at the front of a border
- Cut spent spikes to keep the plant tidy
- Use it along walkways or in small spaces
Through the seasons
Water new plants regularly until roots settle. Established plants want moderate water through summer bloom, with deep soaks rather than frequent sprinkles. Stems die back in winter and regrow in spring, so water only lightly while it rests. Korean mint gets a moderate water rating from WUCOLS on the north-central coast and the south coast, and in the Central Valley and South Inland. WUCOLS marks it as not suited to the low desert. The high desert has no WUCOLS evaluation for it.
In pots
Korean mint grows well in a large pot near a seat, where you can brush its fragrant leaves. Fill it with a well-drained mix. Water once the upper couple of inches have dried, until it runs from the bottom. In summer, check every few days, since flowering plants in pots dry quickly. Keep the saucer empty. Cut spent spikes to tidy it. In winter, after the stems die back, water only lightly.
- A year
- 17.11 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Korean Mint: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.37 | 0.4 | 0.78 | 0.78 | – | – |
| Feb | 0.53 | 0.65 | 0.81 | 0.87 | – | – |
| Mar | 0.87 | 1.09 | 1.15 | 1.3 | – | – |
| Apr | 1.18 | 1.52 | 1.4 | 1.61 | – | – |
| May | 1.46 | 2.08 | 1.61 | 1.95 | – | – |
| Jun | 1.61 | 2.48 | 1.74 | 2.29 | – | – |
| Jul | 1.61 | 2.67 | 1.98 | 2.51 | – | – |
| Aug | 1.49 | 2.39 | 1.86 | 2.33 | – | – |
| Sep | 1.24 | 1.8 | 1.49 | 1.86 | – | – |
| Oct | 0.87 | 1.18 | 1.15 | 1.33 | – | – |
| Nov | 0.47 | 0.56 | 0.84 | 0.9 | – | – |
| Dec | 0.31 | 0.34 | 0.65 | 0.68 | – | – |
| Year | 12 | 17.11 | 15.5 | 18.41 | – | – |
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 Korean mint. Plants that drink alike can share one valve and one schedule.
DahliasDahlia spp.moderate water, Central Valley2.67 gal/sq ft in July
FernsNephrolepis cordifolia (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in July
DayliliesHemerocallis spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in July
BegoniasBegonia & ssp. & cvs. (shade in the desert)moderate water, Central Valley2.67 gal/sq ft in July
Calla LiliesZantedeschia aethiopica SHADE IN DESERTmoderate water, Central Valley2.67 gal/sq ft in July
SageSalvia officinalis and cvs.moderate water, Central Valley2.67 gal/sq ft in July
Bicolor MonkshoodAconitum cammarummoderate water, Central Valley2.67 gal/sq ft in July
Garden MonkshoodAconitum napellusmoderate water, Central Valley2.67 gal/sq ft in July
Carpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in July
Snowdrop WindflowerAnemone sylvestrismoderate water, Central Valley2.67 gal/sq ft in July
Mountain SandwortArenaria montanamoderate water, Central Valley2.67 gal/sq ft in July
Swamp MilkweedAsclepias incarnatamoderate water, Central Valley2.67 gal/sq ft in July
Orange MilkweedAsclepias tuberosamoderate water, Central Valley2.67 gal/sq ft in July
Greater MasterwortAstrantia majormoderate water, Central Valley2.67 gal/sq ft in July
Hardy BegoniaBegonia grandismoderate water, Central Valley2.67 gal/sq ft in July
Wax BegoniaBegonia semperflorensmoderate water, Central Valley2.67 gal/sq ft in JulySimilar plants that need less water 16
Rated lower than Korean mint in the Central Valley. Worth a look for a new bed or a lawn replacement.
AgapanthusAgapanthus orientalislow water, Central Valley1.07 gal/sq ft in July
GeraniumsPelargonium x hortorum and cvs.low water, Central Valley1.07 gal/sq ft in July
SalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in July
IrisesIris germanicalow water, Central Valley1.07 gal/sq ft in July
SucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Russian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
YarrowAchillea millefolium (non-native hybrids)low water, Central Valley1.07 gal/sq ft in July
Mountain AlyssumAlyssum montanumlow water, Central Valley1.07 gal/sq ft in July
Silver SageSalvia argentealow water, Central Valley1.07 gal/sq ft in July
Purple MulleinVerbascum phoeniceumlow water, Central Valley1.07 gal/sq ft in July
Silvery YarrowAchillea clavennaelow water, Central Valley1.07 gal/sq ft in July
Fern Leaf YarrowAchillea filipendulinalow water, Central Valley1.07 gal/sq ft in July
California Native YarrowAchillea millefolium (CA native cultivars)low water, Central Valley1.07 gal/sq ft in July
Woolly YarrowAchillea tomentosalow water, Central Valley1.07 gal/sq ft in July
Perennial HollyhockAlcea rosea cvs.low water, Central Valley1.07 gal/sq ft in July
Mountain Lady's MantleAlchemilla alpinalow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes Korean 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 Korean mint in summer?
In July, established Korean mint 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 Korean mint need per day?
In July in the Central Valley, established Korean 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 Korean mint change across California?
Yes. WUCOLS rates Korean mint 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, not evaluated in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
Does Korean mint attract pollinators?
Yes, its purple flowers attract bees, butterflies and hummingbirds. It suits pollinator gardens. Plant it in groups.
Do deer eat Korean mint?
It tolerates browsing from deer and rabbits. That suits gardens near wild areas. Pollinators still visit freely.
Why is it called blue licorice?
Its leaves have a licorice scent. Other names include Indian mint and purple giant hyssop. Brush the leaves to smell it.
Where does Korean mint grow wild?
It grows in mountain regions of eastern Asia, especially along stream banks. In gardens it wants full sun and drainage. It fits small spaces well.
Does Korean mint come back each year?
Yes, it is a perennial that dies back in winter and regrows in spring. Water lightly while it rests. Cut old stems in late winter.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Agastache rugosa, 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