I’ve had a number of queries regarding the proper watering of native California oaks during this drought. I wrote an article on Oak Tree Care in 2012, and most is current, but I wanted to re-tap some experts for tips during this drought. So along with a quick review and some good and bad pruning examples, here you go.
Oak trees are stately, majestic trees that can live for hundreds of years With their imposing stature and immense, expansive canopies, oak trees make a dramatic statement in any landscape However, to keep your oak trees healthy and thriving for decades to come, proper watering is essential. In this complete guide, we will cover everything you need to know about watering oak trees correctly.
Understanding Oak Tree Watering Needs
Oak trees need a lot of water especially when they are actively growing in spring and summer. During hot dry periods an mature oak tree can transpire over 100 gallons of water per day! This is why consistent, deep watering is so important. Oak trees have a deep taproot along with an extensive network of lateral roots that extend far beyond the drip line. The root system requires abundant moisture in order to supply the massive canopy with water and nutrients.
When to Water Oak Trees
- Newly planted oak trees: Water young trees daily for the first week, then every other day for 2-3 weeks to establish roots.
- Spring/Summer: Water mature oak trees 2-3 times per week during growth season.
- Fall/Winter: Water once per week or when soil dries out. Reduce frequency.
- Dry periods: Increase watering to 2-3 times per week if less than 1 inch of rain per week.
How Much Water Do Oak Trees Need?
Oak trees need about 1-2 inches of water per week, either through rainfall or manual watering. The amount may increase during hot, dry weather or decrease during cool, wet weather. To measure watering:
- Place empty tuna cans throughout the root zone
- Water tree until cans have 1-2 inches of water
- For larger trees, use sprinklers & water for 2-3 hours
Watering Methods for Oak Trees
- Drip Irrigation – Most efficient. Delivers water slowly to root zone.
- Soaker Hose – Releases water along length of hose. Place around drip line.
- Sprinkler – Set sprinkler at base of tree. Allows wide water distribution.
- Hand Watering – Use hose or bucket. Water entire area under canopy & just beyond.
How to Water Oak Trees
- Water slowly and deeply – wet full root zone
- Water at dripline – outer reach of branches
- Water early morning or evening to reduce evaporation
- Allow soil to slightly dry between waterings
- Adjust frequency based on weather & soil type
Signs Your Oak Tree Needs Water
- Leaves wilting or curling
- Yellow/browning leaves
- Smaller than normal leaf size
- Premature fall color/leaf drop
- Dieback in branches
- Slow growth
Problems From Over & Under-Watering
Overwatering can lead to
- Root rot
- Fungal diseases
- Oxygen deprivation
- Tree decline/death
Underwatering can lead to:
- Drought stress
- Premature fall color
- Dieback
- Susceptibility to pests/disease
- Tree decline/death
Getting watering right is crucial for oak tree health!
When to Call an Arborist
If you suspect your oak tree is struggling with moisture stress, call a certified arborist right away for an expert evaluation. They can assess soil conditions, perform health checks, and offer solutions. Acting quickly can help get your tree the water it needs before irreversible damage occurs.
Watering oak trees properly is an ongoing process. Pay attention to weather patterns, soil moisture, and the tree’s condition to determine optimal watering frequency and volume. With attentive, consistent watering, you can keep your majestic oak trees healthy and thriving for generations to come. Their grandeur is well worth the effort.
Water this Winter if Drought Continues
Think of oak trees in the wild. They exist on natural rainfall, with growth slowing during the late summer heat. The normal recommendation is to not water them in the summer months, and only provide water other seasons during unusually dry periods. With our ongoing dryness, I checked in with native plant expert Bart O’Brien, now the director of a prominent native plant botanic garden, the Regional Parks Botanic Garden in northern California. Here are his recommendations for recently planted oaks and old ones.
For long-established oaks, O’Brien suggests deep watering in winter through early spring during periods of drought. So unless, we have an El Nino that brings in considerable rain, consider extra watering this winter. “Luckily, this time period is when landscape use of water is lower during winter, and it provides these majestic trees the water they need when they can actually use it,” O’Brien says.
Most experts agree that water should never be introduced to an old oak in the summer, especially for trees that did not grow up with summer water, because it may encourage root fungus diseases that are often fatal. The late Bert Wilson of Las Pilitas Nursery, a native plant nursery in Escondido, recommended that if your old trees have received irrigation water most of their life, keep the same regimen. But, if watering was a recent introduction, remove it gradually – over a period of a year or so.
Also, check the irrigation spray in your yard. It’s important to avoid spray hitting the trunk. And because water at the base of the trunk causes most root diseases, avoid watering six to eight feet around the trunk of a mature oak tree.
Watering with Newly Planted Oaks
If you have an oak that you or a previous owner has planted O’Brien provides slightly different guidelines:
- For an older tree – 15 plus years – that has been in the landscape for years, continue the irrigation regime that the tree has grown up with as that is what it has adapted to
- For younger trees, keep in mind that you can get a newly planted oak to adapt to drier conditions
- Water new plantings – You will have to water a newly planted oak for at least a few summers before it will survive with minimal to no summer water, says O’Brien, adding that the size of the tree when planted, and your soil conditions play role. For example, a tree planted in clay soil will require less water.
Cut down your Water Oak Trees | Catherine Arensberg
FAQ
What does an overwatered oak tree look like?
Signs of an Overwatered Tree
Yellow, wilting leaves – While potentially caused by another condition, wilting yellow leaves are a sign of overwatering. Fungal growth, musty smell, and oozing – This is a sign of root rot, a fungal condition that develops when roots are drowned by overwatering.
Do oak trees like wet soil?
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Edge Of The Woods Native Plant Nursery, LLChttps://edgeofthewoodsnursery.comNine Reasons to Plant an OakSep 7, 2023 — An oak for almost every site Pin and Swamp White tolerate moist soil. Swamp White can even tolerate occasional standing water. Scarlet, Chestnut, and…
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Russell Tree Expertshttps://www.russelltreeexperts.comTrees that Love Wet “Feet” – Russell Tree ExpertsApr 29, 2020 — They do have amazing fall color though and tolerate wet conditions if properly sited. … And last there are a couple of trees in the oak family as …
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Reddit · r/arboristshttps://www.reddit.comWatering established oak trees : r/arborists – RedditJun 5, 2023 — As a general rule White oak is tolerant of a wide range of soils but prefers moist well draining soil while tolerating dry soil and wet soil for shor…
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Nature Hills Nurseryhttps://naturehills.comEverything You Need to Know About Oak Trees!May 3, 2024 — Oak Tree Soil and Moisture Needs Oaks need well-drained soil but many can become incredibly drought tolerant once established. There are many Oaks th…
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fasttreeremovalatlanta.comhttps://www.fasttreeremovalatlanta.comEverything You Need to Know about Oak Trees – Fast Tree Service AtlantaPreferred Soil – Oak trees are highly adaptable (growing in acidic, alkaline, loamy, moist, sandy, well-drained, and clay soils). While the tree prefers average…
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ScienceDirect.comhttps://www.sciencedirect.comToo wet for oaks? Inter-tree competition and recent persistent wetness predispose oaks to rainfall-induced dieback in Atlantic rainy forestIn our study case, oaks predisposed to die by sustained inter-tree competition and recent persistent wetness were more prone to be severely affected by an addit…
What is the best method for watering trees?
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Why it’s important:Deep watering encourages roots to grow down, making the tree more resilient to drought and wind. Shallow watering can lead to a shallow root system that is easily dried out.
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How to do it:
- Soaker Hoses: Place a soaker hose around the tree’s drip line and run it for several hours.
- Drip Irrigation: Install drip lines within the tree’s drip line to provide a steady stream of water.
- Slow Watering: Use a low flow rate or a bubbler attachment to slowly deliver water to the soil, allowing it to soak in.
- Tree Watering Bags: These bags can be filled and then slowly release water into the soil around the tree.
- Hand Watering: If using a hose, turn the water to a low flow rate and move it around the drip line, says Russell Tree Experts.
- Soaker Hoses: Place a soaker hose around the tree’s drip line and run it for several hours.
How do you keep oak trees healthy?
It is particularly critical that the trunks of oak trees remain dry. However, if the winter season is unusually dry, then a supplemental irrigation in the early spring can complement natural rainfall. Water deeply, to one to two feet, in the outer two-thirds of the root zone.