WateringTimesWatering plan, $19
Melissa officinalis, WUCOLS IV

How often to water lemon balm in California

In July in the Central Valley, established lemon balm 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. Lemon balm is a bushy mint relative grown for its lemon-scented leaves. Established plants tolerate dry spells well, but the roots still need a deep soak once the soil dries out. Left unchecked, it spreads readily by rhizomes and self-sown seedlings.

Ground coverPerennialRated for 3 of 6 zones

How often to water lemon balm, 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 lemon balm 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 3 to 4 inches down at the clump edge signals established lemon balm needs a soak
  • Leaves wilting by midday in full sun can indicate the root zone has dried out
  • Flower spikes fading fast in hot weather can follow a spell of dry soil at the roots
  • Yellowing lower leaves over soggy soil can indicate the bed is holding too much water
  • Leggy, sparse growth in part shade does not by itself indicate a watering problem

How to water it

  • Water lemon balm at the base of the clump, soaking the root zone rather than the foliage
  • Let the top couple inches of soil dry between soakings once the clump is established
  • Grow it inside a bottomless buried container or root barrier if planted in open garden soil
  • Mulch around the clump to steady soil moisture through hot, dry stretches
  • Cut spent flower stalks back promptly to limit self-sown seedlings that need their own water

Through the seasons

A new lemon balm start needs even moisture while its roots establish through the first summer. Established clumps tolerate dry spells between soakings and often need little help once settled. Top growth dies back in cold weather and returns from the crown and spreading roots in spring. Irrigation matters most from spring through fall during active growth and flowering. Winter rain covers the cool months on the north-central coast, in the Central Valley and on the south coast, where WUCOLS rates it moderate water. WUCOLS has not evaluated it for South Inland, the high desert or the low desert.

In pots

Lemon balm suits a container well, since a pot also blocks its rhizomes and self-sown seedlings from escaping into garden beds. Check the mix a couple of inches down often during California summer heat, especially on a sunny patio. Water when it dries, let excess run through the drainage holes, then empty the saucer. Growth dies back in cold weather, so let the mix dry further and check before watering through winter.

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
0.671.32.02.70.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.671.32.02.70.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Lemon Balm: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.78–––
Feb0.530.650.81–––
Mar0.871.091.15–––
Apr1.181.521.4–––
May1.462.081.61–––
Jun1.612.481.74–––
Jul1.612.671.98–––
Aug1.492.391.86–––
Sep1.241.81.49–––
Oct0.871.181.15–––
Nov0.470.560.84–––
Dec0.310.340.65–––
Year1217.1115.5–––

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 lemon balm. Plants that drink alike can share one valve and one schedule.

DahliasDahlia spp.moderate water, Central Valley2.67 gal/sq ft in JulyStar JasmineTrachelospermum jasminoides and cvs.moderate water, Central Valley2.67 gal/sq ft in JulyHoneysuckleLonicera japonicamoderate water, Central Valley2.67 gal/sq ft in JulyFernsNephrolepis cordifolia (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in JulyDayliliesHemerocallis spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyBegoniasBegonia & ssp. & cvs. (shade in the desert)moderate water, Central Valley2.67 gal/sq ft in JulyIvyHedera helixmoderate water, Central Valley2.67 gal/sq ft in JulyCalla LiliesZantedeschia aethiopica SHADE IN DESERTmoderate water, Central Valley2.67 gal/sq ft in JulyStrawberriesFragaria spp. & cvs. (CA native and non-natives species)moderate water, Central Valley2.67 gal/sq ft in JulySageSalvia officinalis and cvs.moderate water, Central Valley2.67 gal/sq ft in JulyBicolor MonkshoodAconitum cammarummoderate water, Central Valley2.67 gal/sq ft in JulyGarden MonkshoodAconitum napellusmoderate water, Central Valley2.67 gal/sq ft in JulyCarpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in JulySnowdrop WindflowerAnemone sylvestrismoderate water, Central Valley2.67 gal/sq ft in JulyGreen Supreme ManzanitaArctostaphylos uva-ursi 'Green Supreme'moderate water, Central Valley2.67 gal/sq ft in JulyMassachusetts ManzanitaArctostaphylos uva-ursi 'Massachusetts'moderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

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

BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyAgapanthusAgapanthus orientalislow water, Central Valley1.07 gal/sq ft in JulyGeraniumsPelargonium x hortorum and cvs.low water, Central Valley1.07 gal/sq ft in JulyLantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in JulyIrisesIris germanicalow water, Central Valley1.07 gal/sq ft in JulySucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyJunipersJuniperus spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRussian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyYarrowAchillea millefolium (non-native hybrids)low water, Central Valley1.07 gal/sq ft in JulyMountain AlyssumAlyssum montanumlow water, Central Valley1.07 gal/sq ft in JulySagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in JulySilver SageSalvia argentealow water, Central Valley1.07 gal/sq ft in JulyPurple MulleinVerbascum phoeniceumlow water, Central Valley1.07 gal/sq ft in JulySilvery YarrowAchillea clavennaelow water, Central Valley1.07 gal/sq ft in JulyFern Leaf YarrowAchillea filipendulinalow water, Central Valley1.07 gal/sq ft in July
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes lemon balm, 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 lemon balm in summer?

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

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

Yes. WUCOLS rates lemon balm 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, not evaluated 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.

Why is lemon balm taking over my garden bed?

It spreads by both rhizomes and self-sown seedlings once established. Cut spent flower stalks before they set seed to slow the spread. A buried barrier or container keeps the roots from traveling further.

How do I water lemon balm after planting?

Keep the new root ball evenly moist while it settles into the bed. Expand the soaked area gradually as roots spread outward. Once established, let the surface dry between soakings.

Can lemon balm handle being planted in a hot, sunny spot?

Full sun works well on the coast, but afternoon shade helps in hotter inland gardens. Watch for leaves wilting by midday as a cue to check soil moisture. Part shade also slows how fast the soil dries.

Does lemon balm need water through winter?

The stems collapse once temperatures drop, and the plant needs little water at that point. Check that the crown is not sitting in soggy soil after rain. Growth resumes with regular checks once new shoots appear.

Why are my lemon balm leaves turning yellow?

Yellowing lower leaves paired with wet soil often point to a bed holding too much water. Let the surface dry before the next soak and confirm the bed drains well. Persistent yellowing in dry soil can instead suggest a nutrient or light issue.

Is lemon balm considered a thirsty herb in California?

WUCOLS rates it a moderate water user across the coastal and valley zones where it has been evaluated. It is not a plant marketed as drought proof. Established clumps still tolerate some dry stretches between soakings.

More plant watering guides

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Sources