How to Water a Tree
Watering Strategies for Happy and Healthy Trees
Learn how to crack the code and determine the perfect watering schedule for your trees.
Trees are vital components of both our landscapes and environment. They serve as the architectural anchors of outdoor spaces, forming the backbone around which entire gardens are designed. Trees bring height, dimension and texture to the landscape, and offer shade and shelter, inviting people to linger and enjoy being outdoors. Beyond their visual and functional attributes, trees play an essential role in the environment by absorbing carbon dioxide and releasing oxygen, mitigating urban heat, improving air quality, and providing habitat for wildlife. It’s no wonder that mature, healthy trees can increase the property value of a home up to 20%. Proper watering plays a crucial role in the health and longevity of these leafy wonders.
Why do Trees Need Water?
Survival - just like any other plant, trees need water to survive. Water is crucial for nutrient uptake, photosynthesis, and overall cellular function. Without an adequate water supply, trees become stressed, which can make them susceptible to diseases, pests, and ultimately lead to their decline.
Growth - water is the primary building block of life, and trees are no exception. Adequate hydration is necessary for a tree to grow and develop properly. A well-watered tree will produce more leaves, flowers, and fruits, contributing to the overall beauty of the landscape.
Resilience - properly watered trees are more resilient to environmental stresses such as extreme temperatures and drought. They can better withstand harsh weather conditions and recover more quickly from damage.
Air Quality - trees act as natural air purifiers by absorbing pollutants through tiny openings in their leaves. When adequately watered, they can perform this vital function effectively, improving air quality in our neighborhoods.
Erosion Control - trees with healthy root systems help stabilize soil and prevent erosion. Without proper watering, their root systems may weaken, making them less effective at soil retention.
How Much Water Should you Give a Tree?
The watering requirements for a tree can vary significantly depending on several factors, and there is no one-size-fits-all prescription. This absence of a universal watering guideline can be exasperating for gardeners!
Being attentive to your trees and the environmental factors that impact them will enable you to adjust your watering schedule accordingly, ultimately promoting healthier growth and overall success. Get to know your trees and their environment by developing an awareness of the following factors:
The type of tree. Each type of tree has a different preference for soil moisture, so make sure you understand your tree’s unique needs. For example, Yoshino and Kwanzan cherry trees like consistently moist soil and will not tolerate periods of drought, while a mature White Fringetree can tolerate dry soil and short periods of drought. If you are buying a new tree, ask the nursery staff for guidance, or refer to the plant’s tag. If you are not sure what type of trees are growing on your property, use a plant identification app such as Pl@ntNet or PictureThis, and do some online research to better understand the moisture preferences of your individual tree species.
The stage of growth. Newly planted trees need lots of water. Lots and lots of water. Generally more than the beginning gardener anticipates. It takes time for young trees to develop a root system that can absorb enough water and become established. Make sure you are available to water new trees frequently and deeply, and are able to carve out time in your schedule for this recurring commitment. Don’t plant a new tree in the spring if you plant to be away for most of the summer. As trees mature and their root systems become more complex, they will need less supplemental watering.
The weather: Temperature, rainfall, humidity, drying winds, cloud cover, and seasonal changes all play a part in determining how often you should water your trees. Developing a flexible watering schedule that takes into account ever-changing weather conditions will help you to provide the right amount of water your trees need. Do not rely on vague forecasts of “evening thunderstorms” to provide enough water for your trees - frequently, storms don’t develop or do not provide a deep enough watering.
The type of soil. The type of soil in your garden plays a crucial role in determining the frequency of watering. Sandy soil drains fast and tends to dry out quickly; clay soil retains water for longer periods of time and can become waterlogged. Loamy soil strikes a balance between water retention and drainage. If you are not sure what type of soil you have, do this easy at-home soil test with water, soil and a spatula.
The light exposure. Increased levels of sunlight and temperature will contribute to higher rates of water loss through the leaves of a tree.
The topography. The way water flows and collects on your property due to its topography plays a vital role in determining the water distribution and absorption patterns in your garden. In areas where the land is sloping, water flows downwards and the soil does not retain as much water. Conversely, low-lying areas and depressions are prone to water accumulation. Terraced areas and raised beds will dry out quickly, as will pots and planters. Observing the movement of water across your property during a storm can offer valuable insights to help you better decide when and how much to water your trees.
The competition. Competition from other tree roots, especially mature trees with extensive root systems, can significantly influence how often you will need to water.
The heat. Radiated heat from various sources, such as driveways, patios, walkways, and sidewalks, can contribute to increased evaporation and water loss. Trees exposed to radiated heat may need more frequent waterings.
The size. All plants like to be watered deeply. Larger trees have bigger root balls and more complex root systems, will need a longer and deeper watering than smaller ones.
Where is the Best Place to Water a Tree?
Do not water the base of the tree’s trunk - doing so can increase the risk of fungal diseases and rot.
Water the roots of a tree, rather than the leaves. The roots are the tree's lifeline, responsible for absorbing water and essential nutrients from the soil.
Direct the flow of water towards ground and the tree’s root zone. Do not water the leaves, or the base of the tree’s trunk. Watering the leaves of a tree can lead to issues like fungal disease, and excessive moisture near the trunk can lead to rot and other health issues.
A tree's root zone, often called the “critical root zone”, is the area surrounding the base of the trunk, where the majority of the root system is concentrated. It typically extends from the tree's trunk to the drip line, which is the outermost edge of the tree’s canopy. A layer of mulch, 3-4 inches deep, will also help to conserve soil moisture in the root zone.
How Long Should I Water a Tree?
Again, there is no one-size-fits-all prescription for how often and how much to water your trees. These are general guidelines you can use to help you begin to form a watering plan, taking into account each tree’s individual moisture preference and the environmental factors discussed above. Before watering, check the moisture level of your soil (more on that below). Always water deeply - this encourages the development of a strong, complex root system and a healthy tree. Deep, less frequent waterings are better than frequent, shallow ones. Water until the top 6-12 inches of soil are moistened. Watering in the morning is generally more water-efficient, but with busy life schedules, water at the time of day that is most convenient for you!
A good soaking for a newly planted tree may require 5-10 minutes of hand watering, or 30-60 minutes of water trickling from a hose (more on these techniques below).
Watering larger, mature trees by hand can become time-intensive and impractical. The best strategy is to water using the hose trickle method, for 1-2 hours, or use a soaker hose or drip irrigation system.
Trees planted in containers should be watered until water flows out through the drainage holes. Containers dry out quickly and should be monitored closely.
How Long Should I Water a Tree with a Soaker Hose?
Using a soaker hose to water a tree is an efficient way to ensure your tree receives a deep watering. Soaker hoses work by slowly releasing water directly onto the soil, ensuring that plants receive a deep and thorough watering. The porous material allows water to seep out evenly along the entire length of the hose, minimizing water waste and preventing soil erosion.
To use a soaker hose, lay it in a spiral or zigzag pattern around the base of the tree, positioning it at least 3 inches away from the trunk. Turn on the water until you see a low, steady drip. This slow, steady release allows the water to seep into the soil gradually, deeply watering the tree and minimizing runoff. As a general rule of thumb, a deep watering session with a soaker hose may take anywhere from 1 to 4 hours, depending on the size and type of tree.
How Long Should I Water a Tree During a Drought?
Watering during a drought is crucial for the survival of a tree. Drought conditions can severely stress trees, leading to wilting, leaf loss, and even death if they don't receive adequate moisture. A general guideline is to provide enough water to moisten the soil around the tree to a depth of at least 6-12 inches. This may require watering for 30 minutes to 4 hours, using the hose trickle method, soaker hose, or a drip irrigation system. The goal is to ensure moisture reaches the deeper roots where it's most needed to sustain the tree through drought conditions, without the soil become overly soggy and wet. Regularly monitoring the soil's moisture level and adjusting the watering schedule as needed is crucial to help the tree survive during drought conditions.
How Often Should I Water a Tree?
How often to water newly planted trees:
The key is to keep the root ball consistently moist for a few months after planting. Newly planted trees require a consistent watering schedule for at least two years after planting. These are general guidelines you can use to help you begin to form a watering plan, taking into account each tree’s individual moisture preference and the environmental factors discussed above:
Week 1: Every 1-2 days
Weeks 2, 3 and 4: 2-3 times per week
The remainder of the first year: 1-3 times per week, possibly more during times of drought or high temperatures.
Year two: 1-3 times per week, possibly more during times of drought or high temperatures.
How often to water established trees:
Established trees have mature, complex root systems and require far less attention than newly planted trees. A long, deep watering 1-2 times a month should be sufficient, taking into account each tree’s individual moisture preference and the environmental factors discussed above.
Should I Water my Tree During the Winter?
In general, deciduous trees lose leaves and enter a state of dormancy during the winter months, and do not need supplemental watering. However, newly planted trees are the exception - they have not developed complex root systems yet, and will need extra help with watering during dry winter spells. Water deeply and slowly on warmer days, when the temperatures are above 40 degrees, and allow the water to completely soak into the ground. Stick to watering in the morning or early afternoon, allowing roots to absorb water before soil and air temperatures plummet in the evening.
Evergreen trees do not lose their foliage during the wintertime, and can experience water loss through their leaves during periods of freezing cold temperatures and drying winds. Make sure evergreens are well-hydrated in November and early December, before the cold temperatures set in. If the winter season is dry, without much rain or snowfall, give your evergreen trees a few deep soakings on days when the temperature is above 40 degrees. Earlier in the day is the best time to water, as it allows the plants to absorb moisture before temperatures drop at night and the ground freezes again.
How Can I Tell if a Tree Needs Water?
A moisture meter provides instant feedback on the level of moisture present in the soil.
Checking the moisture level of your soil is crucial for determining when your trees need watering. Here are a few methods you can use to check soil moisture:
Finger Test: The simplest method is to stick your finger a few inches into the soil, and see if the soil feels dry or moist. You can also use a trowel to dig down a few inches and then insert a finger to gauge the soil moisture.
Visual Inspection: Check the soil's surface, and if it looks dry and cracked, it's likely that the deeper layers are also dry. Moist soil usually appears darker and holds its shape better.
Soil Moisture Meter: A soil moisture meter is a handheld device used to measure the level of moisture present in the soil. It typically features a probe that is inserted into the soil, providing instant feedback on whether the soil is dry, moist, or saturated, helping to guide your watering decisions.
How to Water your Trees - A Guide to Different Watering Techniques
Hand Watering:
Description: This traditional method involves using a hose, usually with a nozzle or wand attachment, to water plants by hand.
Advantages: Inexpensive, provides a personal touch, allows you to aim water directly at the roots of the tree and reduce the risk of disease.
Considerations: Time-consuming, especially for larger trees. Dragging the hose around may cause damage to garden plants.
Soaker Hose:
Description: A porous hose laid along the tree’s root zone, allowing water to seep out slowly and directly into the soil. Can be used in conjunction with a timer to automate watering schedules.
Advantages: Consistent, even and efficient water usage. Easy to install and a time-efficient manner of watering for the busy gardener. Relatively inexpensive when compared to other watering systems.
Considerations: The placement of hoses may need to be adjusted as the tree grows. Hoses can potentially clog and leak.
Hose Trickle Method (for trees and large shrubs)
The “hose trickle” method for trees - set the hose on a slow trickle and aim it towards the roots of the plant.
Description: Take the nozzle or wand off your hose, and run it at a slow trickle, aiming towards the tree’s root zone.
Advantages: Waters deeply and promotes root development, more hands-off than hand watering - set a timer and do some other yard work while the tree is being watered!
Disadvantages: Water runoff, uneven distribution of water, greater potential for overwatering if you forget to turn the hose off.
Drip Irrigation:
Description: A system with tubes and emitters that delivers water directly to the plant's root zone in a controlled, slow manner. Can be automated with the use of a timer.
Advantages: Highly efficient water usage and reduced water waste. Precise targeting of the tree’s root zone. Time efficient, hands-off watering approach for the busy gardener.
Considerations: Requires setup and maintenance. The emitters could potentially clog. This method is more expensive when compared to using a soaker hose.
Professional Irrigation System:
Description: A comprehensive automated watering system tailored to a garden's layout and needs.
Advantages: Precise water delivery, covers large areas efficiently, customizable schedules, and often integrates rain sensors for water conservation. Some systems can be controlled by an app, letting you monitor and make adjustments from any location.
Considerations: Requires professional installation and maintenance, initial cost can be high, may require occasional adjustments and maintenance.
Taking the time to learn about your trees and closely observing their growth and appearance will enhance your skills as a gardener and will empower you to make informed decisions about watering. When you pay close attention, the signs of overwatering, under watering, and proper watering will become more apparent:
Signs of your tree being well-hydrated and happy: firm leaves, vibrant and even-colored foliage, active growth, no wilting or drooping.
Signs of overwatering: yellowing or browning of leaves, wilting despite the soil being wet, mold growth on the soil surface, a foul odor emanating from the soil, slow or stunted growth, and dark brown or black mushy roots.
Signs of under watering: wilted or drooping leaves, dry and crispy leaf edges and stems, slowed growth, and a generally dull or lackluster appearance with muted foliage colors.