WateringTimesWatering plan, $19
Arctostaphylos uva-ursi 'Green Supreme', WUCOLS IV

How often to water Green Supreme manzanita in California

In July in the Central Valley, established Green Supreme manzanita 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. Green Supreme is a low evergreen ground cover, a garden form of bearberry manzanita that arose as a chance seedling at Tilden Regional Parks Botanic Garden. Bright green leaves on reddish stems form a dense mat about 6 inches tall that crowds out weeds. It handles dry spells fairly well, yet it looks its best with an occasional summer soak.

Ground coverCalifornia nativeRated for 3 of 6 zones

How often to water Green Supreme manzanita, 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 Green Supreme manzanita 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 under the mat in summer means Green Supreme is ready for a deep soak
  • Leaves losing their bright, glossy green and turning dull in summer heat can point to a dry root zone
  • Bare patches opening in the center are unusual for this cultivar, which has little or no center dieback, so check that spot for wet soil
  • Sections that wilt and brown while the soil stays soggy point to too much water or poor drainage, not thirst

How to water it

  • Water Green Supreme with drip line or a soaker hose run through the mat, rather than overhead spray
  • Soak until water reaches about a foot down, then let the top few inches dry before the next soak
  • Plant on a slope or in well-drained soil, and in heavy clay make sure water drains away after a soak
  • Give it full sun on the coast and part shade at inland sites, where summer soil dries faster
  • Extend the drip line outward as the long runners spread toward a width of up to 12 feet

Through the seasons

Water a new planting through its first summer while the runners root and spread. Once established, it handles dry spells fairly well but looks best with occasional deep soakings through summer. This evergreen keeps its leaves all year, and its sparse spring bloom adds a few pale flowers. WUCOLS rates Green Supreme manzanita moderate water on the north-central coast, in the Central Valley and on the south coast. Winter rain covers the cool months in all three. WUCOLS marks it as not suited to South Inland, the high desert or the low desert.

In pots

Green Supreme spreads wide and low, so a container suits it only as a trailing plant in a wide, shallow bowl or along the edge of a large planter. Use a fast-draining mix. Check the mix 2 inches down every few days in summer, and more often at inland sites. Water until it runs from the drainage holes, then empty the saucer so the roots never sit in water. In winter, let rain do most of the work, but check the pot during long dry spells.

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

Green Supreme Manzanita: 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 Green Supreme manzanita. Plants that drink alike can share one valve and one schedule.

Star JasmineTrachelospermum jasminoides and cvs.moderate water, Central Valley2.67 gal/sq ft in JulyHoneysuckleLonicera japonicamoderate water, Central Valley2.67 gal/sq ft in JulyIvyHedera helixmoderate 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 JulyCarpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in JulyMassachusetts ManzanitaArctostaphylos uva-ursi 'Massachusetts'moderate water, Central Valley2.67 gal/sq ft in JulySerbian BellflowerCampanula poscharskyanamoderate water, Central Valley2.67 gal/sq ft in JulyBunchberryCornus canadensismoderate water, Central Valley2.67 gal/sq ft in JulyKenilworth IvyCymbalaria muralismoderate water, Central Valley2.67 gal/sq ft in JulyCranesbillGeranium spp.moderate water, Central Valley2.67 gal/sq ft in JulyGreen CarpetHerniaria glabramoderate water, Central Valley2.67 gal/sq ft in JulySpotted DeadnettleLamium maculatummoderate water, Central Valley2.67 gal/sq ft in JulyLemon BalmMelissa officinalismoderate water, Central Valley2.67 gal/sq ft in JulyJapanese SpurgePachysandra terminalismoderate water, Central Valley2.67 gal/sq ft in JulyMoss PinkPhlox subulatamoderate water, Central Valley2.67 gal/sq ft in JulySpring CinquefoilPotentilla neumannianamoderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

Rated lower than Green Supreme manzanita 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 JulyLantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyJunipersJuniperus 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 JulySagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in JulyCalifornia Native YarrowAchillea millefolium (CA native cultivars)low water, Central Valley1.07 gal/sq ft in JulyWoolly YarrowAchillea tomentosalow water, Central Valley1.07 gal/sq ft in JulyGround Morning GloryConvolvulus mauritanicuslow water, Central Valley1.07 gal/sq ft in JulyRock CotoneasterCotoneaster horizontalislow water, Central Valley1.07 gal/sq ft in JulySouth African GeraniumPelargonium sidoideslow water, Central Valley1.07 gal/sq ft in JulyLippia GroundcoverPhyla nodiflora (Lippia nodiflora) cvs.low water, Central Valley1.07 gal/sq ft in JulyRock SoapwortSaponaria ocymoideslow water, Central Valley1.07 gal/sq ft in JulyMother of ThymeThymus praecoxlow water, Central Valley1.07 gal/sq ft in JulyVancouver Jade BearberryArctostaphylos uva-ursi 'Vancouver Jade'low water, Central Valley1.07 gal/sq ft in JulyTrailing LantanaLantana montevidensis (sellowiana) ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyGermanderTeucrium chamaedrys ssp. & cvs.low 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 Green Supreme manzanita, 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 Green Supreme manzanita in summer?

In July, established Green Supreme manzanita 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 Green Supreme manzanita need per day?

In July in the Central Valley, established Green Supreme manzanita 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 Green Supreme manzanita change across California?

Yes. WUCOLS rates Green Supreme manzanita 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 suited to this region in the South Inland zone, not suited to this region in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Is Green Supreme manzanita drought tolerant?

Fairly, once established, but it is not a plant to forget. WUCOLS rates it moderate water where it is suited. It looks best with an occasional deep soak in summer.

How fast does Green Supreme spread?

It is one of the faster growing manzanitas. Young plants send out long radiating runners, then side branches fill the gaps between them. A single plant can reach about 12 feet across while staying about 6 inches tall.

Does Green Supreme flower much?

Not much. It blooms more sparingly than most manzanitas, with a light scattering of white to pale pink flowers in spring. Grow it for its foliage and dense cover.

Will Green Supreme grow in clay?

Yes. It is noted for growing well in heavier clay soil that has reasonable drainage. Avoid spots where water stands after rain.

Can Green Supreme grow in shade?

It takes full sun to light shade. Coastal plantings do best in sun, while inland plantings prefer part shade, where summers are hotter.

Do deer eat Green Supreme manzanita?

It is listed as deer resistant. Its dense mat also helps keep weeds down, which makes it a useful cover for slopes.

More plant watering guides

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Sources