WateringTimesWatering plan, $19
Yucca elata, WUCOLS IV

How often to water soaptree yucca in California

In July on the north-central coast, established soaptree yucca in loam needs a deep soak only about once a month or less: about 8.8 gallons each time for a plant 4 feet across. Soaptree yucca is a slow-growing desert yucca from Arizona, New Mexico, Texas and northern Mexico. Its thin, pale gray-green leaves have edges that shred into white threads, and in time it builds a trunk. Once rooted it needs very little water in most of California. It needs full sun and fast drainage, and soil that stays wet is the main risk.

ShrubSucculentRated for 5 of 6 zones

How often to water soaptree yucca, 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 soaptree yucca 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 several inches down around a newly planted soaptree yucca's root ball means it is ready for a slow soak
  • Dry old leaves hanging down the trunk as a skirt are normal for this yucca and not a sign of thirst
  • Curly white threads peeling from the leaf edges are a normal trait of the species, not drought damage
  • A year with no flower stalk is normal, since soaptree yucca does not bloom every year
  • A rosette that yellows, softens or leans while the soil stays wet can point to rot from poor drainage

How to water it

  • Plant soaptree yucca on a mound or raised bed so water runs away from its base
  • Water a new plant slowly at the edge of its root ball, then let the topsoil dry before the next soak
  • Cut back to rare deep soaks once it is established, and keep it out of the spray of lawn or flower bed sprinklers
  • Mix sand or other porous material into heavy soil before planting so water drains through quickly
  • Choose a gravel garden or another dry bed in full sun rather than a moist mixed border

Through the seasons

Give a new soaptree yucca a slow soak whenever the soil around its root ball dries, through its first summer. After that it needs little or no irrigation in most gardens. It stays evergreen and takes hard frost. A tall flower spike may rise in late spring or early summer, though not every year. Winter rain covers the cool months on the north-central coast and the south coast, so winter watering is rarely needed there. WUCOLS rates it very low water on the north-central coast, the south coast, South Inland and the high desert. It rates low water in the low desert. WUCOLS has not evaluated it for the Central Valley.

In pots

Soaptree yucca grows slowly enough to live in a large container for years. Use a heavy pot with open drainage holes and a fast-draining, gritty mix. Check the mix 2 to 3 inches down every few days in summer heat, and water only when it is dry there. Soak until water runs out the bottom, then empty the saucer so the base never sits in water. Set the pot where the sharp leaf tips will not catch anyone walking past. In winter, water only after the mix has dried well down.

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

WUCOLS lists Soaptree Yucca as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Soaptree Yucca: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.04–0.080.080.070.31
Feb0.05–0.080.090.090.37
Mar0.09–0.110.130.150.61
Apr0.12–0.140.160.190.78
May0.15–0.160.20.240.98
Jun0.16–0.170.230.291.12
Jul0.16–0.20.250.31.14
Aug0.15–0.190.230.281.04
Sep0.12–0.150.190.210.83
Oct0.09–0.110.130.150.6
Nov0.05–0.080.090.090.38
Dec0.03–0.070.070.070.27
Year1.2–1.551.842.138.43

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 soaptree yucca. 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 ratingGlaucous Scorpion VetchCoronilla valentina glaucanot 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 ratingPurple SpurgeEuphorbia dulcisnot 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 rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes soaptree yucca, 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 soaptree yucca in summer?

In July, established soaptree yucca in loam needs a deep watering about once a month or less on the south coast and about once a month or less 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 soaptree yucca need per day?

In July on the north-central coast, established soaptree yucca needs about 0.1 gallons a day for a plant 4 feet across and about 0.3 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 soaptree yucca change across California?

Yes. WUCOLS rates soaptree yucca separately for each of the six California climate zones: very low water in the North-Central Coastal zone, not evaluated in the Central Valley zone, very low water in the South Coastal zone, very low water in the South Inland zone, very low water in the High and Intermediate Desert zone, low water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

How big does soaptree yucca get?

It grows slowly and can take ten to twenty years to reach full size. In time it can reach about 15 feet tall, with a single or branched trunk. Give it room away from paths, because each leaf ends in a sharp point.

Should I cut off the dead leaves on my yucca?

No. The old leaves stay on and hang down the trunk as a skirt, which is part of this yucca's natural look. It needs no regular pruning. If you do trim it, wear gloves and long sleeves, since the plant can irritate skin.

Why has my soaptree yucca not flowered?

This yucca does not bloom every year, even when it is healthy. When it does, creamy white flowers open on a tall spike in late spring or early summer. Keep to its usual sparse watering rather than adding more to coax a bloom.

Is soaptree yucca safe for dogs and cats?

No. It is listed as harmful to dogs and cats if eaten. Plant it where pets do not chew on plants, and away from play areas where the leaf tips could poke someone.

How cold can soaptree yucca take?

It is frost hardy and rated to handle winter lows of about 5 to 14 degrees F. In the cold months, keep its roots out of standing water. A raised, fast-draining spot helps most in wet winters.

What pests show up on soaptree yucca?

Aphids, scale insects and mealybugs can turn up on it, and yucca leaf spot can mark the leaves. Watering does not cure any of these. Keep the plant in full sun and well-drained soil so it stays vigorous.

More plant watering guides

Formosa Sugar PalmArnicaNeemFrilly BergeniaBismarck PalmCabbage on a StickBasket PlantForest Sedge

Sources