How often to water Carolina jessamine in California
In July in the Central Valley, established Carolina jessamine in loam needs a deep watering about every 20 days: about 2.2 gallons each time for a plant 2 feet across, about 0.8 gallons a week. Carolina jessamine is a fast evergreen twining vine from the southern United States to Central America, reaching 12 to 20 feet on a trellis or arbor. Glossy, dark green leaves often bronze in winter, and sweetly scented, canary-yellow funnel flowers cover it in late winter and spring. Every part is highly poisonous, and it has a high flammability rating.
How often to water Carolina jessamine, 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 3 inches down at the base in summer means Carolina jessamine can take water
- Leaves wilting at the tips in afternoon heat point to a dry root zone
- Leaves bronzing in winter is normal color, not stress
- Fewer flowers in shade point to too little light, not water
How to water it
- Water deeply at the base, then let the top few inches dry
- Plant in full sun in moist, rich, well-drained soil
- Give it a trellis, arbor or fence to twine on
- Prune soon after flowering to shape it
- Keep it away from the house in fire-prone areas
Through the seasons
Water a new vine regularly, since growth is modest until it is established. Once settled, it tolerates short dry spells and needs deeper, less frequent water, more in the south and deserts. It blooms from late winter into spring, and its leaves bronze in cold weather. WUCOLS rates Carolina jessamine low water on the north-central coast and in the Central Valley. On the south coast, in South Inland, in the high desert and in the low desert it carries a moderate water rating.
In pots
Carolina jessamine can grow in a large container with a trellis or spill from a planter over a wall. Use a rich, well-drained mix. Water when the top couple of inches are dry, until it drains through. In summer, check every couple of days. Empty the saucer after each soak. Prune after spring bloom. In winter, water when the mix dries and rain falls short.
- A year
- 6.84 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Carolina Jessamine: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.15 | 0.16 | 0.78 | 0.78 | 0.74 | 0.78 |
| Feb | 0.21 | 0.26 | 0.81 | 0.87 | 0.93 | 0.93 |
| Mar | 0.35 | 0.43 | 1.15 | 1.3 | 1.46 | 1.52 |
| Apr | 0.47 | 0.61 | 1.4 | 1.61 | 1.89 | 1.95 |
| May | 0.58 | 0.83 | 1.61 | 1.95 | 2.39 | 2.45 |
| Jun | 0.64 | 0.99 | 1.74 | 2.29 | 2.85 | 2.79 |
| Jul | 0.64 | 1.07 | 1.98 | 2.51 | 3.04 | 2.85 |
| Aug | 0.6 | 0.95 | 1.86 | 2.33 | 2.79 | 2.6 |
| Sep | 0.5 | 0.72 | 1.49 | 1.86 | 2.14 | 2.08 |
| Oct | 0.35 | 0.47 | 1.15 | 1.33 | 1.46 | 1.49 |
| Nov | 0.19 | 0.22 | 0.84 | 0.9 | 0.93 | 0.96 |
| Dec | 0.12 | 0.14 | 0.65 | 0.68 | 0.65 | 0.68 |
| Year | 4.8 | 6.84 | 15.5 | 18.41 | 21.27 | 21.08 |
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 8
Rated low water in the Central Valley, like Carolina jessamine. Plants that drink alike can share one valve and one schedule.
BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
WisteriaWisteria spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Flowering WoodbineLonicera periclymenumlow water, Central Valley1.07 gal/sq ft in July
FleeceflowerFallopia baldschuanica (Polygonum aubertii)low water, Central Valley1.07 gal/sq ft in July
Cecile Brunner RoseRosa 'Cecile Brunner'low water, Central Valley1.07 gal/sq ft in July
Lady Banks RoseRosa banksiaelow water, Central Valley1.07 gal/sq ft in July
Roger's Red GrapeVitis 'Roger's Red'low water, Central Valley1.07 gal/sq ft in July
Blue Dawn Morning GloryIpomoea acuminatalow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes Carolina jessamine, 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 Carolina jessamine in summer?
In July, established Carolina jessamine in loam needs a deep watering about every 20 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 Carolina jessamine need per day?
In July in the Central Valley, established Carolina jessamine needs about 0.1 gallons a day for a plant 2 feet across and about 0.4 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 Carolina jessamine change across California?
Yes. WUCOLS rates Carolina jessamine separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, moderate water in the South Coastal zone, moderate water in the South Inland zone, moderate water in the High and Intermediate Desert zone, moderate water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
Is Carolina jessamine poisonous?
Yes, it has high severity poison characteristics. Every part is toxic, from roots and stems to flowers and seeds. Keep children and pets from chewing it.
When does Carolina jessamine bloom?
It blooms from late winter into spring with fragrant yellow flowers. Bloom is best in full sun. Prune right after flowering.
Can Carolina jessamine be a groundcover?
Yes, without support it forms a bushy groundcover. With a trellis it climbs 12 to 20 feet. Water a groundcover planting evenly.
Is Carolina jessamine a fire risk?
It has a high flammability rating. Avoid planting it close to the house in fire-prone areas. Choose low-flammability plants there.
Does Carolina jessamine spread?
It can become weedy in disturbed areas. Keep it trained to its support. Remove stray runners.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Gelsemium sempervirens, 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