Pour right

"Plants need water - just how much? What alternatives are there to the watering can? And what role does the watering time play? The most important advice.

Many a radio presenter rejoiced in the beautiful weather and looked forward to the sunshine. According to the German Weather Service (DWD), it was the sunniest March since records began in 1951. But there was actually no reason to celebrate. On the contrary: Just 20 liters of precipitation fell per square meter, far less than the reference value of 57 liters.

Gardeners notice that correct watering is more important than ever. Not only does this help the plants get through dry periods, it also saves money. After all, every German uses an average of 7.6 liters of drinking water per day for irrigation and room cleaning, according to the Federal Association of Energy and Water Management. This corresponds to six percent of his needs. For garden and balcony plants, this is likely to increase in the coming years.

Scientists from the University of Cambridge have used tree rings to study the conditions of the past 2,100 years: the summers in central Europe have never been drier than in recent years.

"One must have the courage to say the earth is dry above."

The Bavarian State Institute for Viticulture and Horticulture (LWG) therefore advises using drinking water sparingly and gives tips for correct watering. Basically, the drier the surface remains, the more precisely the water gets into the soil, the less gardeners need. "You have to have the courage to say that the earth is dry above," says Gottfried Röll, horticultural technician at the LWG.

Many garden owners water incorrectly, for example at midday or in the evening. However, early morning makes sense, because then the ground is still cool and less liquid evaporates. Another common mistake is watering daily, but not enough. Often the amount is just five liters per square meter. The water then does not penetrate far enough into the ground and a large part evaporates. 20 liters bring more, because they penetrate deeper into the ground. "You then only have to water once or twice a week," says Röll - and thus saves up to 15 liters per square meter and week.

However, the soil only absorbs between eight and ten liters of water per hour. The LWG therefore recommends two rounds with a break, for example for breakfast. Especially with watering cans and hoses, gardeners can easily tell when enough is enough. When the soil silts up, it's time to move on to the next plant.

Classic sprinkler systems have high losses

A look at the weather forecast also helps to save water: if heavy rainfall is followed by a dry period, it is often sufficient to wait or just distribute enough water for the plants to last long enough.

A well-known technique also reduces consumption, explains Röll: "Mulching keeps water in the soil and prevents evaporation." However, the approach has often been forgotten by hobby gardeners, the expert complains and calls for a rethink.

Röll has observed that old sayings such as "Hop once saves watering twice" are becoming more and more common among garden owners. "In fact, if you destroy capillary action in the soil by gently chopping the surface, less liquid rises to the top." This means that less water evaporates.

The right casting technique also helps. Classic sprinkler systems have high losses because a lot of water ends up on the plants and evaporates there instead of penetrating the soil. Even the watering can and hose are more targeted. Sweat and bubble tubes with porous walls are even better. 

Drip systems work more sparingly, says Röll: "You need about half as much water compared to a watering can."

To save money, garden owners have another option: they do without drinking water. Instead, they collect rain that lands on the roof of their building in rain barrels or cisterns.

The expert recommends flower boxes with a double bottom

Caution, on the other hand, is advisable with another method. "According to the applicable legal provisions, the withdrawal of water from surface waters requires a permit under water law," warns a spokesman for the Bavarian Ministry of the Environment. Otherwise a fine will be due. The only way to be sure here is to ask the responsible water management office in advance.

Balcony owners can also save. Röll recommends flower boxes with a false bottom that are poured over a funnel: "The surface doesn't get wet, less water evaporates, which definitely saves a third of the consumption." In addition, light plastic containers retain moisture better than dark ones and much better than clay pots. Because they allow water vapor to escape laterally.

Given the increasingly common drought, garden owners should also consider how they design their open space. "If the lawn is mowed short, a lot of moisture evaporates, at least six centimeters of grass blade length, more if you should leave it," recommends Röll. Flower meadows are even better. Because there plants are close together, with different heights. "You only need additional water during long dry periods," explains Röll.

He advises more mixed plantings and perennials, silver summer, Achillea and autumn asters, for example. Prairie grasses cope better with dry phases than native ones. Röll recommends paprika and chili for self-sufficient people: 

"I would plant less zucchini in the future, vegetables such as parsnips have deep roots and can make better use of the available water."