How often to water bicolor monkshood in California
In July in the Central Valley, established bicolor monkshood in loam needs a deep watering about every 5 days: about 1.5 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Bicolor monkshood is a herbaceous perennial about 4 feet tall with deeply divided, glossy dark green leaves and branched spikes of hooded flowers in violet-blue and white. It grows best in deep, cool, moisture-retentive soil in partial shade. Every part is extremely poisonous, so gloves are a must, and it should never grow near vegetables.
How often to water bicolor monkshood, month by month
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.
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.
How to tell it needs water
- Mulched soil dry an inch or two down beside the clump in summer signals bicolor monkshood needs water
- Leaves wilting and browning at the edges in afternoon sun point to heat and dry soil
- Flower spikes fading early in a warm, dry spell can follow a dry root zone
- Stems collapsing at the base in waterlogged soil suggest drainage trouble
How to water it
- Water the clump at its base with drip or a soaker
- Keep the soil evenly moist through the growing season
- Plant in partial shade in deep, humus-rich, moisture-retentive soil
- Mulch thickly to keep the roots cool
- Wear gloves whenever you cut or divide it
Through the seasons
Keep a new plant evenly moist from spring through summer. Established clumps still need moisture throughout the growing season, since they prefer cool soil. It dies back in winter and regrows in spring, flowering in summer. Divisions can be slow to settle. In the Central Valley, WUCOLS rates bicolor monkshood moderate water. WUCOLS marks it as not suited to South Inland, and has not evaluated it for the north-central coast, the south coast, the high desert or the low desert.
In pots
Bicolor monkshood can grow in a deep pot in partial shade, away from where children and pets play. Use a rich, moisture-holding mix that still drains. Water when the top inch dries, until it drains through. In summer, check daily and keep the pot out of hot afternoon sun. Empty the saucer. Cut back dead stems in fall with gloves on. In winter, water lightly while it is dormant.
- A year
- 17.11 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Bicolor Monkshood: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | – | 0.4 | – | – | – | – |
| Feb | – | 0.65 | – | – | – | – |
| Mar | – | 1.09 | – | – | – | – |
| Apr | – | 1.52 | – | – | – | – |
| May | – | 2.08 | – | – | – | – |
| Jun | – | 2.48 | – | – | – | – |
| Jul | – | 2.67 | – | – | – | – |
| Aug | – | 2.39 | – | – | – | – |
| Sep | – | 1.8 | – | – | – | – |
| Oct | – | 1.18 | – | – | – | – |
| Nov | – | 0.56 | – | – | – | – |
| Dec | – | 0.34 | – | – | – | – |
| Year | – | 17.11 | – | – | – | – |
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 bicolor monkshood. Plants that drink alike can share one valve and one schedule.
DahliasDahlia spp.moderate water, Central Valley2.67 gal/sq ft in July
FernsNephrolepis cordifolia (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in July
DayliliesHemerocallis spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in July
BegoniasBegonia & ssp. & cvs. (shade in the desert)moderate water, Central Valley2.67 gal/sq ft in July
Calla LiliesZantedeschia aethiopica SHADE IN DESERTmoderate water, Central Valley2.67 gal/sq ft in July
SageSalvia officinalis and cvs.moderate water, Central Valley2.67 gal/sq ft in July
Garden MonkshoodAconitum napellusmoderate water, Central Valley2.67 gal/sq ft in July
Carpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in July
Snowdrop WindflowerAnemone sylvestrismoderate water, Central Valley2.67 gal/sq ft in July
Mountain SandwortArenaria montanamoderate water, Central Valley2.67 gal/sq ft in July
Swamp MilkweedAsclepias incarnatamoderate water, Central Valley2.67 gal/sq ft in July
Orange MilkweedAsclepias tuberosamoderate water, Central Valley2.67 gal/sq ft in July
Greater MasterwortAstrantia majormoderate water, Central Valley2.67 gal/sq ft in July
Hardy BegoniaBegonia grandismoderate water, Central Valley2.67 gal/sq ft in July
Wax BegoniaBegonia semperflorensmoderate water, Central Valley2.67 gal/sq ft in July
English DaisyBellis perennismoderate water, Central Valley2.67 gal/sq ft in JulySimilar plants that need less water 16
Rated lower than bicolor monkshood in the Central Valley. Worth a look for a new bed or a lawn replacement.
AgapanthusAgapanthus orientalislow water, Central Valley1.07 gal/sq ft in July
GeraniumsPelargonium x hortorum and cvs.low water, Central Valley1.07 gal/sq ft in July
SalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in July
IrisesIris germanicalow water, Central Valley1.07 gal/sq ft in July
SucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Russian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
YarrowAchillea millefolium (non-native hybrids)low water, Central Valley1.07 gal/sq ft in July
Mountain AlyssumAlyssum montanumlow water, Central Valley1.07 gal/sq ft in July
Silver SageSalvia argentealow water, Central Valley1.07 gal/sq ft in July
Purple MulleinVerbascum phoeniceumlow water, Central Valley1.07 gal/sq ft in July
Silvery YarrowAchillea clavennaelow water, Central Valley1.07 gal/sq ft in July
Fern Leaf YarrowAchillea filipendulinalow water, Central Valley1.07 gal/sq ft in July
California Native YarrowAchillea millefolium (CA native cultivars)low water, Central Valley1.07 gal/sq ft in July
Woolly YarrowAchillea tomentosalow water, Central Valley1.07 gal/sq ft in July
Perennial HollyhockAlcea rosea cvs.low water, Central Valley1.07 gal/sq ft in July
Mountain Lady's MantleAlchemilla alpinalow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes bicolor monkshood, 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 bicolor monkshood need per day?
In July in the Central Valley, established bicolor monkshood 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 bicolor monkshood change across California?
Yes. WUCOLS rates bicolor monkshood separately for each of the six California climate zones: not evaluated in the North-Central Coastal zone, moderate water in the Central Valley zone, not evaluated 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 monkshood poisonous?
Yes, it is extremely poisonous if eaten and can harm through skin contact. Always wear gloves. Never plant it near vegetables, where its roots could be mistaken for edible ones.
Can bicolor monkshood grow in sun?
It prefers partial shade, but it tolerates sun if the soil is humus-rich and mulched to stay moist. In hot areas, give it afternoon shade. Keep the soil cool.
How tall does bicolor monkshood get?
It reaches about 4 feet. The flower spikes branch widely. Stake it in windy spots.
When should I divide monkshood?
Divide it in autumn or late winter to keep it vigorous. Plants may be slow to re-establish. Wear gloves and water divisions well.
Does monkshood grow well in California?
It grows better where summers are cool. Inland heat stresses it. Shade and steady moisture help.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Aconitum cammarum, the University of California survey California agencies use for landscape plan reviewRead August 23, 2026 on wucols.ucdavis.edu
- Model Water Efficient Landscape Ordinance, adopted text and appendices, effective 2025-01-02 · monthly reference evapotranspiration per city, Appendix CRead August 23, 2026 on water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/Water-Use-And-Efficiency/MWELO-Rulemaking/Final-MWELO-Text-and-Appendices_20250103.pdf
- UC Statewide IPM Program, irrigation scheduling using evapotranspirationRead September 30, 2026 on ipm.ucanr.edu/PMG/GARDEN/ENVIRON/evap.html
- Shaw and Pittenger, Landscape Irrigation System Evaluation and Management, UC Cooperative Extension, 2009Read September 30, 2026 on ucanr.edu/sites/default/files/2013-02/160836.pdf
- Pittenger, Water Management in Gardens and Landscapes, UC Riverside, 2017Read September 30, 2026 on ucanr.edu/sites/default/files/2017-03/258022.pdf