WateringTimesWatering plan, $19
Hyacinthus spp., WUCOLS IV

How often to water hyacinth in California

In July in the Central Valley, established hyacinth needs about 0.8 gallons a week for a plant 2 feet across. Hyacinths are spring bulbs from Eurasia and the Mediterranean, each bulb usually sending up one dense spike of sweetly scented flowers in mid-spring. Plants stand about a foot tall. They want organically rich, well-drained soil in full sun to part shade, and bulbs rot in soggy ground. All parts are mildly toxic, and handling bulbs can irritate skin.

BulbRated for 4 of 6 zones

How often to water hyacinth, 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 hyacinth and the rest of your yard, on the days your water supplier allows.Get the plan for $19

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.

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 inches down beside the leaves in early spring means hyacinth needs water while it grows
  • Flower spikes coming up short or flopping in a dry spring can follow dry soil
  • Leaves yellowing after bloom is the normal start of summer dormancy
  • Soft, smelly bulbs and no shoots point to bulb rot in wet soil

How to water it

  • Keep the soil moist right after planting to start roots
  • Water during dry spells in winter and spring while leaves are green
  • Taper off water after bloom as bulbs head into dormancy
  • Plant in organically rich, well-drained soil in sun to part shade
  • Remove spent flower spikes so bulbs do not put energy into seed

Through the seasons

Water bulbs right after planting so roots form, then let rain help through winter. Keep soil moist in dry spells until bloom in mid-spring. After flowering, taper off and let the leaves die back, since bulbs rest dry through summer. Flowers often get smaller and looser in later years. WUCOLS rates hyacinth moderate water on the north-central coast, in the high desert and in the low desert. The Central Valley carries a low water rating. WUCOLS marks it as not suited to the south coast and has not evaluated it for South Inland.

In pots

Hyacinths are classic container bulbs, outdoors or forced for winter bloom indoors. Use a well-drained mix and set bulbs close together. Water well after planting, then keep the mix lightly moist while roots and leaves grow. Water when the top inch dries, and let it drain. Empty the saucer to avoid bulb rot. After bloom, let leaves yellow and slowly stop watering. Keep the pot dry through summer.

1 Your climate zone six WUCOLS zones, each from its own reference city
1.07gal per sq ft in JulyLow water use in the Central Valley zone
A year
6.84 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.761.52.33.00.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.761.52.33.00.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.16––0.740.78
Feb0.530.26––0.930.93
Mar0.870.43––1.461.52
Apr1.180.61––1.891.95
May1.460.83––2.392.45
Jun1.610.99––2.852.79
Jul1.611.07––3.042.85
Aug1.490.95––2.792.6
Sep1.240.72––2.142.08
Oct0.870.47––1.461.49
Nov0.470.22––0.930.96
Dec0.310.14––0.650.68
Year126.84––21.2721.08

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 5

Rated low water in the Central Valley, like hyacinth. Plants that drink alike can share one valve and one schedule.

Star of BethlehemOrnithogalum arabicumlow water, Central Valley1.07 gal/sq ft in JulyIvy Leaf CyclamenCyclamen hederifoliumlow water, Central Valley1.07 gal/sq ft in JulySummer SnowflakeLeucojum aestivumlow water, Central Valley1.07 gal/sq ft in JulyWhite Rain LilyZephyranthes candidalow water, Central Valley1.07 gal/sq ft in JulySea SquillDrimia maritimalow 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 hyacinth, 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 water does hyacinth need per day?

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

Yes. WUCOLS rates hyacinth separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, low water in the Central Valley zone, not suited to this region in the South Coastal zone, not evaluated 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.

Should I water hyacinth bulbs in summer?

No, bulbs rest after bloom and rot in wet summer soil. Let the leaves yellow and stop watering. Resume when fall rains or planting time arrive.

Why are my hyacinth flowers smaller this year?

Bulbs grown as perennials often give smaller, more widely spaced flowers each year. Many gardeners plant fresh bulbs. Remove spent spikes to help bulbs.

Are hyacinths poisonous?

All parts are mildly toxic if eaten. Bulbs can also cause skin irritation. Wear gloves when planting.

Can I grow hyacinths in pots?

Yes, they are commonly grown in containers and forced for indoor bloom. Use a well-drained mix. Do not keep them as long-term houseplants.

How do I divide hyacinths?

Division is the usual way to propagate them and also eases crowding. Divide crowded clumps while the bulbs are dormant. Replant at the same depth.

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Sources