How to water trees correctly: The most common mistakes when watering

Many people lovingly care for their trees, yet these trees suddenly show signs of dry leaves, dead branches, or premature leaf drop. The problem is often not a lack of watering, but rather how the trees are watered.

Because when watering trees, it's not just the amount of water that matters. What's also crucial is:

• when watering
• how quickly the water is released
  
• whether the soil can store water
  
• and whether the water even reaches the roots.

Many traditional watering habits date back to a time when summers were cooler and soils were moister. However, climate change has altered these conditions. Long periods of drought, compacted soil, and heat are increasingly taking their toll on many trees.

In this article, we'll show you the most common mistakes when watering trees and what you should pay attention to instead.

Key facts at a glance

• Frequent, shallow watering often does little to help trees.
  
• Slow watering is usually much more effective
  
• Young and old trees have different needs.
  
• Compacted soils exacerbate drought stress
  
• The timing of watering is crucial.
  
• Soil life and mulch also play an important role.

Mistake 1: Watering too often, but too little

Many people water their trees a little bit every day. While this seems sensible at first, it often doesn't help the tree much. Small amounts of water usually remain in the upper layers of soil. There, the water evaporates quickly before it reaches deeper roots.

This creates another problem:
The tree develops more shallow roots close to the surface. These are particularly sensitive to heat and drought. Therefore, infrequent but thorough watering is significantly better. This allows the water to penetrate deeper into the soil and remain available there for longer.

Mistake 2: Pouring too quickly

Especially with dry soils, the following often happens: The garden hose is turned on and large amounts of water are applied to the tree base in a short time. 

The problem is that parched soils often have difficulty absorbing water. A large portion runs off the surface or evaporates. The tree often receives significantly less than expected. A much more effective approach is to release water slowly over several hours. This allows the water to gradually seep into deeper soil layers.

Irrigation bags or drip irrigation systems are particularly helpful. They release water slowly and help the soil to absorb the moisture more effectively.

Mistake 3: Watering at the wrong time of day

Watering at midday in the blazing sun often seems logical, since it's particularly hot then. However, a particularly large amount of water actually evaporates from the surface at this time. Furthermore, many trees are already under stress during the midday heat. Much better options are:

• the early morning hours
• or the evening

This allows the water to seep into the ground more slowly and be used more efficiently.

Mistake 4: Watering only directly at the base of the trunk

Many people water directly at the base of the tree trunk. However, most of the fine roots aren't located there. Important absorption roots are usually further out, in the area beneath the canopy. Therefore, water should be distributed as broadly as possible over the root zone. Older trees, in particular, benefit much more from this than from watering directly at the base of the trunk. Do you use tree watering bags? If so, place them with a stake in the root zone of the tree.

Mistake 5: Treating young and old trees the same

Young trees have completely different needs than old trees. Newly planted or young trees don't yet have a deep root system. They are therefore much more dependent on regular watering. Old trees often reach deeper soil layers. Nevertheless, many large trees are now also suffering from prolonged periods of drought. The following factors are crucial:

• Tree species
• Age
• Location
• ground under
• weather condition

Therefore, there is no single amount of water that all trees need.

Mistake 6: Ignoring compacted soils

Even regular watering is only of limited help if the soil can barely absorb water. Especially in cities, soils are often heavily compacted. Rainwater and irrigation water then run off the surface instead of slowly seeping into the ground. Furthermore, compacted soils often lack oxygen. This further weakens roots and soil life. Healthy soil is therefore an important part of good tree watering. Helpful measures include, for example:

• A layer of mulch
• compost
• Worm compost
• organic fertilizer
• soil loosening
• More greenery (but not necessarily monotonous lawn)

They help the soil to retain water better and remain more fertile in the long term.

Mistake 7: Not watering after summer

Many people stop watering their plants in autumn as soon as the first leaves fall. But that's precisely when trees begin to prepare for winter. Particularly dry autumns can be problematic. Furthermore, many fine roots continue to grow well into autumn.

Evergreen shrubs like cherry laurel or conifers continue to transpire water even in winter. If the ground is frozen at the same time, this can lead to frost desiccation. Young trees, in particular, often benefit from a final, thorough watering before prolonged periods of frost.

How to water trees better

Often, just a few changes can help:

• Water less frequently, but more intensively.
• slowly release water
• Water in the morning or evening
• mulch the soil
• protect the root area
• Promote soil life

What is crucial is not just the amount of water, but whether the water actually reaches the ground.

Why slow irrigation makes sense

Especially during extended dry periods, slow watering can make a big difference. Watering bags release water drop by drop over several hours. This allows it to soak in much more slowly and reach the roots better than quick, shallow watering. At the same time, evaporation is reduced and water is used more efficiently.

This can significantly improve the water supply, especially for young trees or in dry urban locations.

Making good use of rainwater

Rainwater is available free of charge, is usually lower in calcium than tap water, and is part of the natural water cycle. Rain barrels and cisterns can help store precipitation and use it for irrigation during dry periods.

You can find more information in the article "Using rainwater for trees": Why every drop counts.

Frequently asked questions about tree watering

Is it possible to overwater trees?

Yes. Particularly heavy or clay soils can develop waterlogging. This reduces the amount of oxygen reaching the roots.

How can you recognize drought stress?

Typical signs are:

• limp leaves
• premature leaf drop
  
• little Blätter
• dry twigs
• dead branches

More articles on the topic of watering trees

How can I water trees properly?

How to properly water trees throughout the year: The ultimate guide for spring, summer, autumn and winter

Is there enough rain for my trees?

How to water young trees correctly: This is how they grow healthy.

How to properly water old trees: Why even large trees suffer from drought

How to properly water city trees: Why they suffer from drought and how you can help

Watering trees while on vacation