Fertilizing trees with tree watering bags

In this article, you will learn how you can provide your trees with not only water but also nutrients with little effort. 

Why should you fertilize trees at all?

Trees are true survivors. They withstand heat, wind, and cold and can survive for decades or even centuries. But especially in cities and gardens, their natural living conditions are often severely restricted. The soil is compacted, and leaves and organic matter are regularly removed. The result: Many trees suffer from nutrient deficiencies, grow more slowly, are more susceptible to disease, and are less able to cope with drought stress.

Targeted fertilization can help here. It helps trees develop strong roots, maintain healthy foliage, and better cope with environmental stress. Tree irrigation bags allow liquid fertilizer to be applied directly to the roots. But which trees actually need fertilizer? And which fertilizer is suitable for trees? We recommend this article on these topics. Fertilizing trees. 

More than just watering: How to fertilize with the watering bag

If you want to use your tree watering bag for fertilizing, we recommend placing it near the tree's root zone rather than directly at the trunk. Ideally, you should either use multiple bags or place your bag in several locations one after the other to ensure the fertilizer is distributed evenly. 

To place the tree watering bags in the root area, you can use a stake. You can find instructions here. here.

Step by step instructions

• Prepare your fertilizer-water mixture: Dilute in a bucket or watering can in the recommended ratio and stir well.
• Place the watering bag around the tree trunk or stake and zip it up.
• Then fill the First, fill the watering bag with the mixed mixture only about 1/6 full (depending on the bag volume, between 10 and 18 liters) and then lift the bag by the black loops (shake). This is important to ensure the bag is in an upright position, as otherwise the water may not drain properly from the bag.
• Let the watering bag empty as usual.
• After fertilizing, we recommend rinsing the tree watering bag thoroughly with water to remove any residue.

Which fertilizers are suitable for tree watering bags?

It's important that you only use liquid fertilizer. It's also important that you only use well-dissolved liquids, as otherwise the small openings can easily become clogged.

We also generally recommend using organic liquid fertilizers. These include, for example, Worm tea, compost tea, or plant manure. These products not only provide nutrients but also promote soil life.

Make sure your liquid fertilizer doesn't corrode the material of the bag. Most tree watering bags are made of PVC or PE.

How is the fertilizer dosed?

It's important to note at this point that soils can also be overfertilized. We therefore recommend applying too little fertilizer and then adding more fertilizer later if nutrient deficiencies occur further.

We recommend that you always follow the manufacturer's instructions. In most cases, this will be a ratio of 1:10 to 1:20. A ratio of 1:10 would mean 1 liter of liquid fertilizer to 10 liters of water.

Important: Always follow the manufacturer's instructions and use products that are suitable for trees.

When is the right time to fertilize?

To ensure your trees get the most benefit from fertilization, timing is crucial. Trees have different needs depending on the season:

• Spring (March to May): During this phase, the trees begin their growth period. Fertilization supports leaf growth, the formation of new shoots, and strengthens the tree for the upcoming season.
• Summer (June to July): During prolonged drought, a good water supply is usually more important than fertilization. Only in cases of visible nutrient deficiencies (e.g., yellow leaves, weak growth) may a light top-up be beneficial.
• Late summer (August to September): After hot summer months, moderate fertilization helps trees regenerate and store reserves for the winter. 
• Autumn and winter (from October): From this point on, no further fertilization should be applied. Late applications of fertilizer stimulate new shoot growth, which cannot mature before the frost. This makes the trees more susceptible to cold damage.

What should you avoid?

Here are the most important points:

• Solid fertilizers (e.g. horn shavings) do not belong in the bag – they do not dissolve and can block the drainage.
• Avoid over-fertilization: Less is often more, especially with young trees.
• Do not use foaming additives, as they may interfere with the water flow.
• Do not fertilize when the ground is frozen or extremely dry – lightly 

Try now!

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