Watering is a key, necessary aspect to ensure a flourishing garden: plants are comprised of approximately 80% water, and its only means of drawing up nutrients from the soil, which it does by absorbing nutrients in a water-based solution through its roots. A few rules need to be followed to ensure proper watering. Just like too little water, too much can have a negative effect on plant growth.

With this guide, we give you practical tips to help you make your garden a blooming oasis and use the precious resource of water efficiently. 

Proper watering plays a crucial role in the development of plants. Whether it’s houseplants, ornamental garden or vegetables gardens – it’s worth taking a closer look at the topic of watering so that you can develop the right watering approach for your garden.

WHY DO WE WATER AT ALL? 

Everyone knows that our plants need water to survive. But why is that and how do the plants absorb the water? In this article, we’ll explain how the nutrients that are essential for survival get from the water into the plant and why photosynthesis simply doesn’t work without water. But one step at a time… 

WATER UPTAKE HAPPENS THROUGH THE ROOTS 

Our plants absorb most of the water that is so important for them from the soil. To do this, a plant uses its roots. Depending on the type of plant, the development of the root system and the plant’s own ability to absorb water from the environment also varies: 

• If a plant has a deep and extensive root system, it has more potential to access the precious moisture from its surroundings. Many trees and shrubs have such an extensive root system and are therefore virtually independent of our irrigation. Only in the growing phase after being planted do these plants need our support in absorbing water. After a year, most trees and shrubs have grown so well that, under normal circumstances, no additional watering is necessary. 

• On the other hand, if the roots are merely fine and short, water can only be drawn from the nearby environment for absorption. This is true for quite a few annual plants and/or perennials and certainly pot plants. If drought persists, additional watering is necessary. Plants that respond quickly to a lack of water by drooping their leaves, such as hydrangeas, petunias or sunflowers, can act as indicator plants to give you a better sense of when to water. Over time, this will help you develop a natural sense of the plants’ needs. 

The so-called capillary effect plays an essential role in water absorption. Through the fine root system, the nutrients dissolved in the water are absorbed into the plant’s core. In this way, all the essential nutrients enter the plant for further use. Important plant nutrients are nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S). Iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), molybdenum (Mo) and chlorine (Cl). 

FACTORS INFLUENCING IRRIGATION 

We now know why plants need water and the ways in which it is provided. With this knowledge, we can now ensure to water our plants ourselves. However, the amount of water we should apply depends on various factors. 

• Clearly, the plant itself determines how much water it needs. There are plants that are very frugal and require very little water – and there are also plants that require daily watering under certain conditions. For example, vegetables such as garlic, onions, shallots, asparagus and artichokes require little water, while squash, lettuce, tomatoes and cabbages require a lot of water. Consider this important plant characteristic in your planning and adapt it to the given location.  

• The location of your plants will affect additional watering as well. Do your plants face north or south, are they exposed to wind and rain or are they sheltered? These are all important parameters that play a role in defining customized irrigation. In sunny and windy locations, plants evaporate much more water and thus need to be supplied with significantly more water. 

• Different soil types differ in their ability to store water. Sandy soils, for example, can store significantly less water available to plants and have limited water-holding capacity. Clay soil, on the other hand, is very good at storing water in a way that is available to plants. A clay soil with a silty, clumpy texture that resembles coffee grounds is ideal. To maintain and improve the soil, you can regularly add some compost and turn it at the surface with a digging pitchfork from time to time. By interrupting the capillary action of the soil surface through tillage, the soil evaporates less water. A positive side effect is that weeds are thus prevented from growing and are undermined.  Mulching is much easier and requires less effort. The soil is covered by a layer of mulch, which can consist of various materials, such as bark mulch, leaves or clippings, and at the same time is supplied with organic matter. This reduces evaporation from the soil and you can get by with much less watering all year! 

• The more rain, the less we need to apply additional water. Therefore, a rain gauge makes sense in any garden to determine exactly how much water has entered the garden naturally. 1 mm of rain equals 1 liter of water per m². You will be surprised when you read the numbers on your meter: Heavy rainfall that lasts a few minutes often brings less water than a fine drizzle that lasts several hours. Rainwater is also better than tap water. It’s not as cold, it doesn’t contain chlorine, and it’s definitely less expensive – the ideal solution is to set up a rainwater collection tank. This reduces water consumption and is also easy on the wallet. 

• Plants have different needs at different times of the year. Think in advance about the needs of plants at different times of the year and what watering measures should be taken. In autumn and winter, the weather conditions mean that less watering is needed than in spring and summer, when the amount of watering should be adapted to the climate. 

WATERING MISTAKES 

The motto “a lot helps a lot” has become almost normal- but in addition to the right amount of water, there are other mistakes that are often made when watering plants. 

• A common mistake gardeners make is watering at too high a frequency. In this case, plants do not develop their own root system to search deeper for water and become dependent on the surface water provided. The rule is: few intensive waterings that reach deeper soil layers are more useful than many small waterings that only irrigate the top soil layer. 

• An incorrectly measured amount can, in the worst case, cause damage to our plants. If the plants are always offered too much water, the risk of waterlogging increases and the roots can rot. In addition, nutrients are unnecessarily flushed out. In addition to poor growth, this can even lead to the death of the plant. Check from time to time with a spade how deep the soil is moistened, in the vegetable garden or in the lawn this is easily possible. In addition, use a rain gauge – so you can easily determine whether you still need to water in addition to natural precipitation or not. Furthermore, there are moisture meters to measure the moisture in the soil and determine if and how much you should still water. 

• When watering, especially in the summer months, make sure you do it at the right time. Watering in the early morning or evening is much more tolerable for your plants and for your wallet than in the blazing midday sun. That’s because water evaporates in bright sunlight before it can seep into the soil and be absorbed by the plants. 

• Favour application with the good old watering can, drip systems at the base of the plant, or recessed irrigation systems for larger areas. Sprinkling or spraying plants uses more water and encourages disease, especially in tomatoes, potatoes and beans.