WateringTimesWatering plan, $19
Coronilla valentina glauca, WUCOLS IV

How often to water glaucous scorpion vetch in California

In July on the north-central coast, established glaucous scorpion vetch in loam needs a deep watering about every 13 days: about 8.8 gallons each time for a plant 4 feet across, about 4.6 gallons a week. Glaucous scorpion vetch is a small, bushy evergreen shrub from the Mediterranean, in the pea family. Its blue-gray leaves are divided into leaflets, and heads of fragrant, rich yellow flowers open in spring and summer. It wants full sun, some shelter and soil that drains freely. Give it deep soaks spaced well apart, with the top of the soil drying in between.

ShrubRated for 2 of 6 zones

How often to water glaucous scorpion vetch, month by month

Your city
Plant width
4 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 glaucous scorpion vetch 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 inches down beside a young scorpion vetch means its small root ball is ready for a slow soak
  • Blue-gray leaflets that still hang limp in the cool of the morning, over dry soil, point to a thirsty shrub
  • Leaves that yellow and drop from inside the bush while the soil stays wet for days point to poor drainage, not thirst
  • A cluster of honey-colored mushrooms at the base of a failing plant can mark honey fungus, a root rot favored by waterlogged soil

How to water it

  • Water a new scorpion vetch over its root ball and a little beyond it, then widen the wet ring as the bush fills out
  • Soak slowly until water reaches about a foot down, then let the top few inches dry before the next soak
  • Use drip emitters or a slow hose at the base so the dense, low stems and the root crown stay dry
  • Plant in a sunny, sheltered spot, and set it on a low mound where heavy clay holds water after rain
  • Mulch with gravel or a thin layer of bark, kept a few inches clear of the stems

Through the seasons

Give a new plant deep soakings through its first summer, while its roots spread beyond the nursery ball. After that, longer gaps between soaks suit it. It stays evergreen all year and flowers from spring into summer, so spring and summer soil checks matter most. On the north-central coast, WUCOLS rates it moderate water, so summer soaks are still needed there. It rates low water on the south coast. Winter rain covers the cool months in both coastal zones. WUCOLS marks it as not suited to South Inland. WUCOLS has not evaluated it for the Central Valley, the high desert or the low desert.

In pots

This compact shrub stays under about 3 feet tall and wide, so it can live in a large pot on a sunny patio or beside a warm wall. Use a gritty, fast-draining mix and a pot with open drainage holes. Check the mix 2 inches down every few days in summer, and more often in a heat wave. Water until it runs from the holes, then empty the saucer at once. In winter, let the mix dry further between soakings, and move the pot under an eave if rain keeps it soggy.

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

WUCOLS lists Glaucous Scorpion Vetch as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Glaucous Scorpion Vetch: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.37–0.31–––
Feb0.53–0.32–––
Mar0.87–0.46–––
Apr1.18–0.56–––
May1.46–0.64–––
Jun1.61–0.69–––
Jul1.61–0.79–––
Aug1.49–0.74–––
Sep1.24–0.6–––
Oct0.87–0.46–––
Nov0.47–0.33–––
Dec0.31–0.26–––
Year12–6.2–––

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 not evaluated in the Central Valley, like glaucous scorpion vetch. Plants that drink alike can share one valve and one schedule.

Formosa Sugar PalmArenga englerinot rated, Central Valleyno Central Valley ratingChilean Feather BambooChusquea culeou (C. breviglumis)not rated, Central Valleyno Central Valley ratingBlackbrushColeogyne ramosissimanot rated, Central Valleyno Central Valley ratingWillowleaf CotoneasterCotoneaster salicifoliusnot rated, Central Valleyno Central Valley ratingMadagascar SagoCycas thouarsii (SHADE)not rated, Central Valleyno Central Valley ratingIrish HeathDaboecia cantabricanot rated, Central Valleyno Central Valley ratingButterfly PalmDypsis lutescens (Areca)not rated, Central Valleyno Central Valley ratingUmbrella BambooFargesia murielaenot rated, Central Valleyno Central Valley ratingBlue Fountain BambooFargesia nitida (Sinarundinaria nitida) (BAMBOO)not rated, Central Valleyno Central Valley ratingPrickly HeathGaultheria mucronata (Pernettya mucronata)not rated, Central Valleyno Central Valley ratingOtterbossieGossypium harknessiinot rated, Central Valleyno Central Valley ratingBox-leaved HollyIlex crenatanot rated, Central Valleyno Central Valley ratingBellyache BushJatropha gossypiifolianot rated, Central Valleyno Central Valley ratingMountain LaurelKalmia latifolianot rated, Central Valleyno Central Valley ratingBarbados CherryMalpighia glabranot rated, Central Valleyno Central Valley ratingSiberian CypressMicrobiota decussatanot 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 glaucous scorpion vetch, 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 glaucous scorpion vetch need per day?

In July on the north-central coast, established glaucous scorpion vetch needs about 0.7 gallons a day for a plant 4 feet across and about 2.6 gallons a day for a plant 8 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 glaucous scorpion vetch change across California?

Yes. WUCOLS rates glaucous scorpion vetch separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, not evaluated in the Central Valley zone, low 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 glaucous scorpion vetch fragrant?

Yes. Its rich yellow, pea-like flowers are scented, and one of its other names is day-smelling coronilla. Plant it beside a path, patio or sunny wall where the scent can be enjoyed in spring and summer.

How big does glaucous scorpion vetch get?

It is a small shrub, usually about 1.5 to 3 feet tall and about as wide. It can take 10 to 20 years to reach that size. It fits rock gardens, courtyards, borders and the base of a sunny wall.

Will scorpion vetch grow in clay soil?

Yes, it grows in clay, loam, sand or chalky soil, as long as water drains away. In heavy clay, plant it on a low mound and space the soaks further apart. Standing water around the roots is the bigger risk.

Why are mushrooms growing at the base of my scorpion vetch?

Clustered, honey-colored mushrooms at the base of a declining shrub can signal Armillaria root rot, also called honey fungus or oak root fungus. This shrub is listed as susceptible. In California, most deaths from this fungus follow excess irrigation or other stress, so fix drainage and keep the root crown dry in summer.

Does glaucous scorpion vetch need full sun?

Yes. It grows best in full sun with some shelter, such as a south or east facing wall. Coastal gardens suit it well. A sheltered, sunny spot also dries the soil between soaks.

More plant watering guides

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Sources