How often to water Brazilian nightshade in California
In July on the south coast, established Brazilian nightshade in loam needs a deep watering about every 11 days: about 2.2 gallons each time for a plant 2 feet across, about 1.4 gallons a week. Brazilian nightshade is an evergreen, twining vine of the nightshade family, grown for drooping clusters of bluish purple flowers with yellow anthers. Scarlet berries follow, and its stems, leaves and fruit are poisonous if eaten. It tolerates drought but not frost, and it self-sows so freely that it is invasive in many areas.
How often to water Brazilian nightshade, 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 1.5 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.
How to tell it needs water
- Soil dry a few inches down at the base of the vine during summer bloom means it needs a deep soak
- Lobed leaves still drooping the next morning, with dry soil below, point to a thirsty vine
- Frost-damaged leaves are cold injury, not thirst, so do not answer them with extra water
- Wilting and yellowing leaves while the soil stays wet can mean root rot, so let the soil dry before the next soak
How to water it
- Water Brazilian nightshade at the base with drip or a slow hose, keeping water off the stems
- Soak the root zone deeply, and hold off until the top few inches dry out
- Plant it in organically rich, well-drained soil in full sun to part shade
- Spread mulch over the root zone, keeping it clear of the base of the stems
Through the seasons
Water a new Brazilian nightshade regularly in its first summer as the roots take hold. Established vines tolerate drought, but soil checks still matter during summer bloom. Flowers open in mid to late summer, followed by scarlet berries. The vine stays evergreen where frost does not reach it. On the coast, winter rain usually takes over in the cool months, so cut back irrigation then. WUCOLS rates Brazilian nightshade moderate water on the south coast. WUCOLS has not evaluated it for the low desert, the high desert, South Inland, the Central Valley or the north-central coast.
In pots
A large pot with a trellis keeps Brazilian nightshade in bounds and makes stray seedlings easy to spot. Every few days in summer, dig a finger into the mix and water when the top 2 inches feel dry. Soak until water seeps from the holes, and do not leave the pot standing in its saucer. The vine does not tolerate frost, so move the pot to a frost-free spot before cold nights. Pick off ripe berries before they drop, since they are poisonous and seed freely.
- A year
- no figure
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
WUCOLS lists Brazilian Nightshade as not evaluated for the Central Valley zone, so no monthly figure is computed here.
Monthly water need by climate zone
Brazilian Nightshade: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | – | – | 0.78 | – | – | – |
| Feb | – | – | 0.81 | – | – | – |
| Mar | – | – | 1.15 | – | – | – |
| Apr | – | – | 1.4 | – | – | – |
| May | – | – | 1.61 | – | – | – |
| Jun | – | – | 1.74 | – | – | – |
| Jul | – | – | 1.98 | – | – | – |
| Aug | – | – | 1.86 | – | – | – |
| Sep | – | – | 1.49 | – | – | – |
| Oct | – | – | 1.15 | – | – | – |
| Nov | – | – | 0.84 | – | – | – |
| Dec | – | – | 0.65 | – | – | – |
| Year | – | – | 15.5 | – | – | – |
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 10
Rated not evaluated in the Central Valley, like Brazilian nightshade. Plants that drink alike can share one valve and one schedule.
Variegated KiwiActinidia kolomiktanot rated, Central Valleyno Central Valley rating
Anemone ClematisClematis montananot rated, Central Valleyno Central Valley rating
Privet-Leaved JasmineJasminum leratiinot rated, Central Valleyno Central Valley rating
Chilean BellflowerLapageria roseanot rated, Central Valleyno Central Valley rating
Etruscan HoneysuckleLonicera etruscanot rated, Central Valleyno Central Valley rating
Tatarian HoneysuckleLonicera tataricanot rated, Central Valleyno Central Valley rating
Golden Flame HoneysuckleLonicera x heckrottinot rated, Central Valleyno Central Valley rating
Amur River GrapeVitis amurensisnot rated, Central Valleyno Central Valley rating
Crimson Glory VineVitis coignetiaenot rated, Central Valleyno Central Valley rating
Beach Morning GloryCalystegia soldanellanot rated, Central Valleyno Central Valley ratingTurn this into minutes on your water days
Every city page has a calculator that takes Brazilian nightshade, 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 Brazilian nightshade need per day?
In July on the south coast, established Brazilian nightshade needs about 0.2 gallons a day for a plant 2 feet across and about 0.8 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 Brazilian nightshade change across California?
Yes. WUCOLS rates Brazilian nightshade separately for each of the six California climate zones: not evaluated in the North-Central Coastal zone, not evaluated in the Central Valley zone, moderate water in the South Coastal zone, not evaluated 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 Brazilian nightshade poisonous?
Yes. The stems, leaves and berries are all toxic when swallowed. Plant it away from where children play, and clear fallen berries.
Is Brazilian nightshade invasive?
It self-sows aggressively and is considered invasive in many areas, where it forms dense stands that overwhelm native plants. Pull seedlings while they are small. Cutting off spent flower clusters before berries form keeps new seedlings down.
Where does Brazilian nightshade come from?
Its original range is unclear, despite the name. Some authorities place it in dry forests and scrub of the West Indies and coastal Colombia and Venezuela. Others suggest a wider range, from southern Florida and Mexico through Central America, tropical South America and the West Indies.
Can Brazilian nightshade survive frost?
No, it is intolerant of frost and rated hardy only in USDA zones 11 and 12. In California, give it a frost-free spot or grow it in a pot you can move under cover.
What does Brazilian nightshade climb on?
It is a twining vine that typically grows to about 20 feet. Give it a trellis, fence, arbor or gazebo, and guide new stems onto the support.
What pests bother Brazilian nightshade?
It has no serious pest problems, but watch for aphids, whiteflies, spider mites and thrips. Powdery mildew and rots can also occur. Wet soil favors root rot, so let it dry between soakings.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Solanum seaforthianum, 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