Save your trees from extreme heat

Everything you need to know about tree care during a heat wave

All trees are vulnerable to extreme heat, especially in the first few years after planting. While we must conserve water during a drought, losing trees will only make heat waves worse. That's because trees provide the much-needed shade that lowers temperatures.

Healthy trees are also crucial to maintaining our local water supply: when it finally rains, a mature tree can capture thousands of gallons of rainwater in its canopy and root zone, sinking the rain into an aquifer!

Fortunately, we've gathered the essential tree care tips so you can keep yours thriving.

  • Here's what to consider

    It can be challenging to know if your tree needs water, because it depends on the age of your tree, the type of soil where it's planted (sand, clay, silt, loam), and how well your soil drains. Soils with higher clay content and compacted soils will take longer to wet, and will stay wet longer. Sandier soils will drain faster, meaning they need more water, more often.

    A simple way to test

    Take a long screwdriver (or something similar) and poke the soil surrounding your tree. If the screwdriver doesn't go past 6 inches, it's time to water!

    You can also dig down at least 4 inches and check for moisture. The surface will dry out quickly, but if the soil below ground is still very wet, water less often.

  • Water young trees weekly

    Young and newly planted trees require frequent watering for their first 3-5 years in the ground. Water newly planted trees weekly week with 10-15 gallons of water. Once your tree has been in the ground for a year, you can water it every other week.

    A small, rounded mound of dirt or mulch around your tree can serve as a good watering perimeter and help guide water to the root zone.

    Water mature trees deeply

    After 3-5 years in the ground, mature trees are considered "established" and require less water.

    Slowly water mature trees 1 to 2 times per month with a simple soaker hose, about 9 inches from the trunk out to the edge of the farthest branches (the drip line). This is where the majority of feeder roots are. Try to saturate the soil 6-12 inches deep.

  • Use recycled water

    Keep your trees healthy and help LA beat the drought by using recycled water to care for your trees! Keep a bucket in your shower, and collect water in it while the shower warms up.

    Don't prune your trees during a drought.

    Pruning creates additional stress for your trees. Be sure to wait to prune until we've had plenty of rain

    Add mulch. Lots of mulch.

    4 to 6 inches of mulch help to slow evaporation, keep the weeds down, cool the root zone, and create a healthier environment for the beneficial microorganisms in the soil. Head to the app for free mulch!

    Watch the weather

    If rain is in the forecast, let Mother Nature do the watering. She does a great job!

    Make a DIY drip-irrigation bucket

    Drill a small 1.8" hole in the bottom of a 5-gallon container. Place the container near the drip line, fill it with water, and let it slowly drain on its own. Watering slowly better saturates the soil around your tree's roots.

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