How can I water trees properly?

Do we really need to water our trees? Isn't that what the rain is for?
That's generally correct. However, especially during the summer months, rainfall is often insufficient. But how do you water trees properly? We'll look at that step by step now. 

How to water trees correctly: The 5 most important rules

Here are the most important rules to get you started. You can find more information in the relevant chapters.

• 150–200 liters per watering They also reach deep roots
• Water 1-2 times per week instead of small amounts daily
• Watering in the morning, to avoid evaporation
• Water slowlyso that water penetrates deep
• Young trees They tend to need additional water.

Table of Contents
Why watering trees is important
How trees absorb water
How trees store water
How much water do trees need?
How often should you water trees?
When should you water trees?
Young vs. old trees
Soil and irrigation
Watering city trees correctly
Irrigation methods compared
Hose and watering can
Drip irrigation
Sprinkling
Our watering recommendation
Watering trees throughout the year
Winter
Spring
Summer
Autumn
More tips
Typical mistakes
storing water in the soil

Why do we need to water our trees?

Due to climate change, there are increasingly long periods of heat and drought. This means that there is no rain for a long time, the ground becomes extremely dry and our trees are very thirsty. This so-called Drought stress can ultimately lead to tree death.

You can recognize signs of drought stress by wilting leaves, premature leaf drop, or dying branches. These are the first signs that your tree urgently needs water. You can find more information in this video.

How exactly does a tree absorb water?

Trees primarily absorb water through their roots. This water is then transported from the roots through the trunk and branches to the leaves. The roots of our trees extend to varying distances and depths into the soil.

Here we differentiate between shallow roots, deep roots and heart roots. The root system of the Shallow roots is, as the name suggests, distributed very shallowly beneath the earth's surface. Water absorption therefore mainly takes place via surface water that seeps through the earth.
The roots of the Deep roots are grown very deep in the ground. The water is mainly absorbed from the deeper regions, as a main root drifts towards the groundwater.
Heart root These two abilities are combined. The roots grow partially diagonally downwards and can simultaneously branch out laterally, thus absorbing water in different ways. Therefore, it is important to understand your tree's root system.

How do trees store water?

Similar to us humans, trees store water in every single cell. The water supply is in the roots, in the trunk, in the branches, in the leaves and also in the fruits. The bigger the tree is and the more leaves, needles or fruits it has, the more water it can store. When this reservoir is fully filled, our trees can survive for a long time without an additional water supply.

Due to the prolonged periods of drought in recent years, the trees' water reserves are being depleted, and a natural water supply is no longer possible. Once these reserves are empty, the tree enters an emergency mode. The leaves wither, are shed, and the entire tree dries out. Without water, the trees also close their stomata, preventing them from photosynthesizing. This protective mechanism means that the trees are unable to produce energy precisely when they have the most sunlight available. 

How much water does a tree need?

There is no general answer to this question. The amount of water always depends on the size and location of the tree. A medium-sized tree aged around 5 to 6 years is happy about 150 to 200 liters of water per irrigation session. This corresponds to about 2 to 3 filling quantities of one 75 liter watering bag.

How often should you water trees?

Trees especially need support when it is very hot and dry for a long period of time. You can help the trees best if you tell them something twice a week Give your tree a good watering. This feels much better to the tree than watering it daily with a small amount of water. Ideally, the trees should be watered in the morning.

When should you water trees? Here's how to recognize their need.

Whether a tree needs water can often be determined using simple means:

• A good indicator is the soil itself. If the top layer of soil is dry and there's hardly any moisture even a few centimeters below, it's time to water. You can easily check the soil with your finger or a small spade.
• The tree also shows signs of water shortage. These include drooping or curled leaves, a dull leaf color, or premature leaf drop.
• At the latest when it has been hot and dry for several days and no rain has fallen, you should take action and support the tree.

Young vs. old trees: How different their water requirements are

A tree's water requirements depend heavily on its age. Here are the most important guidelines:

• Young trees in the first five years after planting are particularly dependent on regular watering. Their root system is not yet well developed and can only absorb water from a limited area. Therefore, they should also be watered during moderate dry periods.
• Older, established trees have a significantly larger root system and are often better able to provide for themselves. They generally only require additional water during prolonged dry periods. Nevertheless, even for them, targeted irrigation can be beneficial during extremely hot summers.

How the soil affects irrigation

Not all soils retain water equally well. That's why it's important to know the composition of your soil in order to adjust watering correctly.

• Sandy soils allow water to drain away very quickly. In these cases, it is advisable to water more frequently, as the moisture does not remain in the root zone for long.
• Clay or loamy soils, on the other hand, retain water much better. In this case, you should water less frequently, but more slowly and evenly so that the water can penetrate deep into the soil.
• If the soil is heavily compacted, water can often only drain away superficially. In such cases, it helps to carefully loosen the top layer of soil.
• A mulch layer It can also help to retain moisture in the soil and reduce evaporation.

Watering city trees correctly

Whether in Berlin, Munich or Hamburg: Urban trees face unique challenges and often require more support than trees in rural areas. Sealed surfaces like asphalt and paving typically restrict their root space. At the same time, cities heat up more intensely in summer, further increasing their water needs.

Furthermore, rainwater often cannot seep directly into the root zone but is instead diverted away. This makes urban trees particularly susceptible to drought stress, and they greatly benefit from regular watering during dry periods.

How to water trees correctly: The best watering methods compared

We can support our trees with various watering methods to quench their thirst. Here's an overview of the most important methods:

The garden hose and the watering can

Watering cans and garden hoses are the classic methods for watering trees. You can use tap water or collected rainwater from a rain barrel. However, for the tree, watering with a hose or watering can means a real flood of water all at once. The water runs off so quickly that the roots barely have a chance to absorb it. 

With the garden hose, you never know how much water you have supplied the tree with.

The drip irrigation

To properly water trees, we recommend drip irrigation. By this you can understand a form of long-term irrigation. Here, small amounts of water are evenly released to the roots through small openings on watering bags, hoses or pipes. This type of irrigation is possible both above and below ground.

A particularly simple and effective form of drip irrigation is the use of irrigation bags. These are attached directly to the trunk and release water slowly and evenly over several hours. This ensures that the water reaches exactly where it is needed: the root zone.

The baumbad watering bags They are designed precisely for this purpose. They enable targeted, water-saving irrigation and ensure that even larger quantities of water are released in a controlled and efficient manner.

Drip irrigation has the advantage that the roots get enough time to absorb the water and thus supply the whole tree. At the same time, thanks to the watering bag, you always know exactly how much water your tree is being supplied with. Water should not be wasted, especially because of the increasing drought.

You can find a lot more information about drip irrigation in the separate article:
"The drip irrigation in detail"

Sprinkling as a watering method

By sprinkling you can understand the open spraying of water over a large area. With this type of irrigation, the water supply in the soil can be optimized so that the roots are supplied with water even during a dry season.

Our watering recommendation: drip irrigation

Drip irrigation is the best way to water trees optimally. Other watering methods are always well-intentioned and do help a little. However, they usually result in too much water being wasted or the water not even reaching the roots.

The Irrigation bags are designed precisely so that the water is delivered drop by drop to the roots. And at the same time, due to the capacity of 75 or 100 liters per bag, they enable you to water with a large amount of water in one watering session. This means that the water reaches where it is needed in a quantity that is comfortable for the tree.

Watering trees throughout the year: spring, summer, autumn and winter

Due to ongoing climate change and the associated changes in temperatures and precipitation, dry phases can always occur, regardless of the season.

Watering trees in winter

During the winter months, trees are in a regenerative dormancy phase and generally do not require additional watering. However, in recent years it has become apparent that there is increasingly less precipitation even in winter, and soil moisture in some regions continues to decrease during this time of year, preventing groundwater reserves from replenishing sufficiently. This has consequences for the water supply of trees in spring.

You can find more information about this in the article: "Watering trees in winter"

Watering trees in spring

After the mostly rainy months of January and February, it is becoming increasingly common for our trees to need additional water in March and April. An adequate supply of water is extremely important for trees, especially at the beginning of the growing season. In this phase, the trees want to produce shoots and lots of leaves. And if they don't get enough water here, growth will be immediately delayed. Depending on the amount of precipitation in March and April, it is helpful or even necessary to support the trees at regular intervals.

You can find more information about this in the article: "Watering trees in spring"

Watering trees in summer

The summer months of June to August are months in which it may well be necessary to regularly support a tree. Especially young trees and city trees with smaller roots than older and free-standing trees sometimes need our support several times a week.

You can find more information about this in the article: "Watering trees in summer"

You can find more about watering city trees in the separate article:
"How to properly water and save city trees"

Trees water in autumn

From September onwards, a tree generally only needs support if it has shown signs of drought stress in the preceding months. With the onset of autumn, the trees gradually lose their leaves and prepare for regeneration. However, even at this stage, they still need sufficient water, as they continue to produce secondary plant compounds to defend themselves against pathogens and pests.

You can find more information about this in the article: "Watering trees in autumn"

More tips for watering trees:

Water and especially drinking water is a valuable resource that we should use sparingly. So here are a few tips for watering. So that as much of the water we use for watering as possible reaches the roots and thus the tree.

Water as early as possible in the morning.

When watering in the midday and afternoon hours, more water evaporates than in the morning hours. And due to the lens effect of the water drops, other plants in the area of ​​the tree disk and roots on the surface can burn due to the stronger solar radiation.

Watering in the evening, on the other hand, promotes fungal infestation on plants and attracts snails. Both have less immediate consequences for the tree. But all the more for the surrounding plants.

It is better to water a larger amount once than just a few liters a day.

Small amounts of water only penetrate the surface of the soil and are generally insufficient to thoroughly moisten the entire soil structure and reach the roots. Therefore, it's better to water less frequently but with a larger volume of water each time. Ideally, this should be 150 to 200 liters, applied once or twice a week. It's also important that the water is released slowly to prevent it from running off the surface.

Periodically loosen the soil around the tree.

Especially with city trees, but also with trees in many gardens, the soil around the tree is often very compacted. As a result, the water often flows off the surface when watering and evaporates. Loosened soil, on the other hand, absorbs water better, so that more irrigation water reaches the roots.

If possible, use process water or rainwater for watering.

On the one hand, trees and other plants in the garden like "soft" low-lime rainwater much better than tap water. On the other hand, drinking water has to be treated and cleaned in a complex manner. Therefore, where possible, service water or rainwater collected via cisterns, rain barrels or water diversion systems should be used for watering instead of drinking water.

Typical mistakes when watering trees

When watering trees, similar mistakes are often made that are easily avoidable:

• A common mistake is watering too frequently with small amounts of water. This only moistens the top layer of soil, while the deeper roots remain dry. It's better to water less often, but with sufficient water.
• Watering directly at the trunk is also not ideal, as the fine roots are mostly located in the outer crown area. The water should therefore be distributed over a wide area around the tree.
• Another mistake is watering at the wrong time of day. In the midday heat, a large portion of the water evaporates before it even reaches the soil. Furthermore, heavily compacted soil can cause water to run off the surface instead of soaking in.

Storing water in the soil: This is how moisture remains available for longer

To use irrigation water as efficiently as possible, it's advisable to improve the soil's water retention capacity. Here are some options:

• A mulch layer of bark mulch, leaves, or grass clippings protects the soil from direct sunlight and reduces evaporation. At the same time, it promotes soil life and improves soil structure in the long term.
• Incorporating compost can also help to loosen the soil and improve its water retention capacity. This allows water to be available to the roots over a longer period.
• A healthy soil structure ensures better water absorption and retention, a crucial factor for the long-term supply of water to the tree. Organic soil improvers such as worm compost are particularly effective. They promote soil life, improve the structure, and help retain water in the root zone for longer. Baumbad liquid fertilizer based on high-quality Worm compost and is particularly well suited to specifically support these effects.
  

In this article you will find even more information about the The interplay of water, soil and nutrients for healthy trees.

Summary: How to water trees correctly

When watering trees, three things are particularly important:

• sufficient water per watering
• the correct frequency
• and a slow, even release in the root area

If you also pay attention to soil structure and water retention, you create the best conditions for healthy and resilient trees.