How often to water Delta Eclipse crepe myrtle in California
In July in the Central Valley, established Delta Eclipse crepe myrtle in loam needs a deep watering about every 20 days: about 8.8 gallons each time for a plant 4 feet across, about 3.0 gallons a week. Delta Eclipse crepe myrtle is a common crape myrtle selection grown for dark burgundy leaves that set off lavender summer flowers. It forms an upright, multi-stemmed shrub or small tree around 10 feet tall. Its roots are shallow and fibrous, and it needs full sun and soil that drains well.
How often to water Delta Eclipse crepe myrtle, 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
- A root ball that feels dry when you dig a few inches beside a young plant calls for a slow, deep watering
- Drooping new shoots in a hot spell, with dry soil just under the mulch, show the shallow roots need water
- Leaves yellowing and dropping in heavy clay that stays wet point to drowning roots, since crape myrtle roots do not tolerate wet soil
- A grayish white powder on buds and young leaves is powdery mildew, uncommon on this resistant selection but still possible
- A black, sooty film on the leaves grows on honeydew left by aphids, not on extra water
How to water it
- Water the root zone under and just beyond the branches with drip or a slow soak
- Run each watering long enough to reach about a foot deep, and wait until the upper few inches have dried
- Plant on a slight rise in heavy clay so water drains away from the roots
- Spread about 3 inches of mulch over the root zone, tapering it to an inch at the trunks
- Give it full sun and open air, and widen the watered area as the clump fills out
Through the seasons
Water a new plant regularly through its first summer. Planting in fall or early spring gives roots time to settle before summer heat. Flowers start in early summer, and fall color is burgundy before the leaves drop and the peeling bark shows. If it needs pruning, do it in late winter or early spring, since flowers form on new growth. WUCOLS rates Delta Eclipse crepe myrtle low water in the Central Valley. WUCOLS has not evaluated it for the north-central coast, the south coast, South Inland, the high desert or the low desert. Winter rain usually covers the bare shrub in the Central Valley.
In pots
At 8 to 10 feet, Delta Eclipse is big for a pot. A young plant can still spend a few seasons in a large, heavy container in full sun. Use a well-drained mix and a pot with ample holes. In summer heat, probe the mix every couple of days and water when the top 2 inches have dried. Water until it runs out below, then empty the saucer. After leaf drop, give only enough water to keep the root ball from drying out completely.
- A year
- 6.84 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Delta Eclipse Crepe Myrtle: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | – | 0.16 | – | – | – | – |
| Feb | – | 0.26 | – | – | – | – |
| Mar | – | 0.43 | – | – | – | – |
| Apr | – | 0.61 | – | – | – | – |
| May | – | 0.83 | – | – | – | – |
| Jun | – | 0.99 | – | – | – | – |
| Jul | – | 1.07 | – | – | – | – |
| Aug | – | 0.95 | – | – | – | – |
| Sep | – | 0.72 | – | – | – | – |
| Oct | – | 0.47 | – | – | – | – |
| Nov | – | 0.22 | – | – | – | – |
| Dec | – | 0.14 | – | – | – | – |
| Year | – | 6.84 | – | – | – | – |
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 low water in the Central Valley, like Delta Eclipse crepe myrtle. Plants that drink alike can share one valve and one schedule.
LavenderLavandula spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
RosemaryRosmarinus officinalislow water, Central Valley1.07 gal/sq ft in July
BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Olive TreesOlea europaea ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Crape MyrtleLagerstroemia spp., hybrids & cvs.low water, Central Valley1.07 gal/sq ft in July
LantanaLantana camara ssp. & 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
AloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
JunipersJuniperus 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
SagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in July
Wild PrivetLigustrum vulgarelow water, Central Valley1.07 gal/sq ft in July
CoralberrySymphoricarpos orbiculatus (SHADE)low water, Central Valley1.07 gal/sq ft in July
Sydney Golden WattleAcacia longifolialow water, Central Valley1.07 gal/sq ft in July
Blue Leaf WattleAcacia salignalow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes Delta Eclipse crepe myrtle, 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 Delta Eclipse crepe myrtle need per day?
In July in the Central Valley, established Delta Eclipse crepe myrtle needs about 0.4 gallons a day for a plant 4 feet across and about 1.7 gallons a day for a plant 8 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 Delta Eclipse crepe myrtle change across California?
Yes. WUCOLS rates Delta Eclipse crepe myrtle separately for each of the six California climate zones: not evaluated in the North-Central Coastal zone, low water in the Central Valley zone, not evaluated 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.
How big does Delta Eclipse crepe myrtle get?
It grows about 8 to 10 feet tall and 4 to 6 feet wide, upright and multi-stemmed. That narrow shape suits small spaces where a full-size crape myrtle would crowd.
Does Delta Eclipse get powdery mildew?
It is rated highly resistant to powdery mildew. The disease is most common when cool nights follow warm days and in crowded plantings with poor air flow. Give it sun and space around the branches.
When should I prune Delta Eclipse crepe myrtle?
Prune in late winter or early spring, before growth begins, because it blooms on the current year's wood. Skip pruning in fall after leaf drop, which can spur tender growth and winter injury. Trimming faded flower clusters in summer can extend the bloom.
Can you overwater Delta Eclipse crepe myrtle?
Yes. Crape myrtle roots do not tolerate wet soil, so constantly soggy clay harms them. Raise the planting in heavy soil and let the upper soil dry between soakings.
Will Delta Eclipse bloom in shade?
Bloom drops off in partial shade and can stop entirely. Plant it in full sun for the best show of flowers against the dark leaves.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Lagerstroemia indica 'Deleb', 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