WateringTimesWatering plan, $19
Campanula poscharskyana, WUCOLS IV

How often to water Serbian bellflower in California

In July in the Central Valley, established Serbian bellflower 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. Serbian bellflower is a low, evergreen groundcover from the northern Balkans, about 8 inches tall and spreading to 3 feet. Its heart-shaped, downy leaves disappear under small, blue, funnel-shaped bells from spring through fall, peaking in midsummer. It likes part sun, or full sun on the coast, in well-drained soil that stays evenly moist.

Ground coverRated for 4 of 6 zones

How often to water Serbian bellflower, 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 Serbian bellflower 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

  • Bellflower leaves turning soft and limp, with soil dry to the first knuckle, call for a drink
  • Leaves scorching in hot inland sun point to too much sun
  • Rotting at the crown in soggy soil points to poor drainage
  • Heavy bloom in midsummer shows the plant has what it needs

How to water it

  • Water gently at soil level once the surface inch has dried
  • Plant in part sun, or full sun near the coast, in well-drained soil
  • Keep the soil evenly moist but never soggy
  • Use it as a groundcover, on walls or at the front of a bed
  • Give it afternoon shade in hot inland gardens

Through the seasons

Give new plants steady water until they knit into a mat. Once rooted, Serbian bellflower likes moderate moisture through its long flowering season, which peaks in midsummer. It keeps its leaves through coastal California winters, and its roots shrug off hard cold. The rainy season usually covers it from late fall into spring. Serbian bellflower gets a moderate water rating from WUCOLS on the north-central coast, in the Central Valley, on the south coast and in South Inland. It is not a desert plant: WUCOLS marks it as not suited to the high desert or the low desert.

In pots

Serbian bellflower trails nicely from a hanging basket or the lip of a window box. Fill it with a mix that drains well but holds some moisture. Soak it as soon as the surface feels dry, and let the excess run out. On warm days, feel the mix daily, and hang the basket where afternoons are shaded. Tip out any water in the saucer. Over winter, add water only if the mix goes dry, and snip off any tired stems.

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

Serbian Bellflower: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.78––
Feb0.530.650.810.87––
Mar0.871.091.151.3––
Apr1.181.521.41.61––
May1.462.081.611.95––
Jun1.612.481.742.29––
Jul1.612.671.982.51––
Aug1.492.391.862.33––
Sep1.241.81.491.86––
Oct0.871.181.151.33––
Nov0.470.560.840.9––
Dec0.310.340.650.68––
Year1217.1115.518.41––

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 Serbian bellflower. 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 JulyGreen Supreme ManzanitaArctostaphylos uva-ursi 'Green Supreme'moderate water, Central Valley2.67 gal/sq ft in JulyMassachusetts ManzanitaArctostaphylos uva-ursi 'Massachusetts'moderate 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 Serbian bellflower 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 Serbian bellflower, 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 Serbian bellflower in summer?

In July, established Serbian bellflower in loam needs a deep watering about every 8 days in the Central Valley, about every 11 days on the south coast and about every 9 days 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 Serbian bellflower need per day?

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

Yes. WUCOLS rates Serbian bellflower 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, moderate water 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.

When does Serbian bellflower bloom?

It blooms from spring through fall, peaking in midsummer. The small blue flowers cover the mat. A white form also exists.

Is Serbian bellflower deer resistant?

It is deer tolerant. That makes it useful near open land. It spreads into a dense mat.

Can Serbian bellflower take full sun?

It takes full sun on the coast. Inland, give it part sun or afternoon shade. Keep the soil evenly moist.

How cold hardy is Serbian bellflower?

Its roots survive very hard cold. It stays evergreen in coastal California gardens.

What other names does it have?

It is also called Poscharsky's bellflower and trailing bellflower. The name honors the German gardener Gustav Poscharsky. A hybrid with Campanula portenschlagiana is sold as 'Birch Hybrid'.

More plant watering guides

Spotted DeadnettleGayfeatherChinese Sweet GumSweet GumTulip TreeSweet Breath of SpringPrivet HoneysuckleTrumpet Honeysuckle

Sources