WateringTimesWatering plan, $19
Polygonatum odoratum (japonicum), WUCOLS IV

How often to water Solomon's seal in California

In July on the north-central coast, established Solomon's seal in loam needs a deep watering about every 6 days: about 1.5 gallons each time for a plant 2 feet across, about 1.8 gallons a week. This is fragrant Solomon's seal, a shade-loving woodland perennial that spreads slowly by rhizomes into colonies of arching stems. Pairs of greenish white, lily-scented bells hang beneath the leaves in late spring. It wants humus-rich soil that stays moist but drains, and it dislikes hot summers.

PerennialRated for 2 of 6 zones

How often to water Solomon's seal, 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 Solomon's seal 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 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.

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 1 to 2 inches down among the stems means Solomon's seal needs water
  • Leaves browning at the edges and stems flopping in summer heat point to dry soil, too much sun, or both
  • Leaves turning yellow in fall as the stems die back is normal before the winter rest
  • Leaves chewed away in late spring usually mean slugs or Solomon's seal sawfly larvae, not thirst
  • Soft, rotting shoots in cold, waterlogged soil point to poor drainage around the rhizomes

How to water it

  • Water at the base of the clump with a soaker hose, keeping the arching leaves dry
  • Soak the soil about a foot deep and keep it evenly moist through spring and summer
  • Plant in part to full shade in humus-rich soil that holds moisture but drains
  • Mulch with leaf mold or compost each year to keep the rhizomes cool and moist
  • Water less once the stems yellow in fall, and cut them back to the base late in autumn

Through the seasons

Keep new plants moist while they root in, and expect slow spread at first. Shoots rise in spring, flowers dangle in late spring to early summer, and blue-black berries follow in fall as the leaves turn yellow. After the stems die back, the dormant rhizomes need little water, and winter rain usually covers them near the coast. WUCOLS rates Solomon's seal high water on the north-central coast and moderate water on the south coast. It is marked not suited to the Central Valley and South Inland. WUCOLS has not evaluated it for the high desert or the low desert.

In pots

Solomon's seal grows well in a deep, wide container in shade, where its rhizomes have room to spread. Use a humus-rich mix that drains. Check it an inch down every day or two in summer, since potting soil dries fast and the plant dislikes heat. Water until it drains out, then empty the saucer so the rhizomes do not sit wet. Through winter, give the pot only enough water to keep the dormant rhizomes from drying out.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Solomon's Seal for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Solomon's Seal as not suited to this region for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Solomon's Seal: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.6–0.78–––
Feb0.84–0.81–––
Mar1.39–1.15–––
Apr1.88–1.4–––
May2.33–1.61–––
Jun2.58–1.74–––
Jul2.58–1.98–––
Aug2.38–1.86–––
Sep1.98–1.49–––
Oct1.39–1.15–––
Nov0.74–0.84–––
Dec0.5–0.65–––
Year19.2–15.5–––

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 10

Rated not suited to this region in the Central Valley, like Solomon's seal. Plants that drink alike can share one valve and one schedule.

Desert RoseAdenium obesumnot rated, Central Valleyno Central Valley ratingKahili GingerHedychium gardnerianumnot rated, Central Valleyno Central Valley ratingAlpine ToadflaxLinaria alpinanot rated, Central Valleyno Central Valley ratingSkunk CabbageLysichiton americanusnot rated, Central Valleyno Central Valley ratingEgyptian Star FlowerPentas lanceolatanot rated, Central Valleyno Central Valley ratingSwedish IvyPlectranthus verticillatusnot rated, Central Valleyno Central Valley ratingPainted DaisyTanacetum coccineum (Pyrethrum roseum)not rated, Central Valleyno Central Valley ratingWandering JewTradescantia fluminensis (SHADE)not rated, Central Valleyno Central Valley ratingMoses-in-the-CradleTradescantia spathacea (Rhoeo spathacea)not rated, Central Valleyno Central Valley ratingHeath-Leafed BanksiaBanksia ericifolianot rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes Solomon's seal, 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 Solomon's seal need per day?

In July on the north-central coast, established Solomon's seal needs about 0.3 gallons a day for a plant 2 feet across and about 1.0 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 Solomon's seal change across California?

Yes. WUCOLS rates Solomon's seal separately for each of the six California climate zones: high water in the North-Central Coastal zone, not suited to this region in the Central Valley zone, moderate water in the South Coastal zone, not suited to this region 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.

Is Solomon's seal poisonous?

Yes. All parts can cause discomfort if eaten, and it is listed as toxic to dogs. Wear gloves when you divide or cut it back.

When should I cut back Solomon's seal?

Cut the stems back to the base in late autumn, once the leaves have turned yellow. Water sparingly over winter while the rhizomes rest.

Can Solomon's seal grow in sun?

It prefers part to full shade and dislikes hot summers. Hot afternoon sun can scorch the leaves, so give it a shady spot and steady moisture.

How do I divide Solomon's seal?

Divide the rhizomes in spring, taking care not to snap the brittle new shoots. Water the divisions well and keep them moist while they settle in.

What is eating my Solomon's seal leaves?

Slugs, snails and Solomon's seal sawfly larvae are the usual culprits. Check under the leaves in late spring and pick off the larvae. The damage does not mean the plant needs more water.

More plant watering guides

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Sources