Wet July: Plants recover, drought damage persists

Berlin. The unusually wet July in many parts of Germany was a boon for plants. "In regions where it rained heavily, the plants that were under stress recovered," says Andreas Marx, head of the Drought Monitor at the Helmholtz Centre for Environmental Research. Plants can draw water from the soil relatively quickly. "This has also been seen in some cities. Withered lawns, it only took a few days for them to slowly turn green again."

However, the condition of the soils varies greatly from region to region, explains the water researcher. In Schleswig-Holstein, Mecklenburg-Western Pomerania, and large parts of Brandenburg, there was twice the amount of precipitation as usual. "If you look at the top 25 centimeters below the surface, the soils in northeastern Germany are really saturated."

The soils in Rhineland-Palatinate, Saarland, northern Baden-Württemberg, and southern Bavaria were also blessed with abundant rain. The top 60 centimeters of soil were unusually wet for the time of year.

In the Ruhr region, large parts of Thuringia, and northern Bavaria, however, significantly less rain fell than usual. Here, the top 60 centimeters were exceptionally dry in places. This is causing difficulties for farmers – for example, with corn planting, which is scheduled for July and August.

Groundwater reserves in Germany are becoming increasingly scarce in more and more regions, warns a new study. In dozens of districts, more groundwater is being extracted than can be replenished. This affects not only regions in the relatively dry east.

"How this develops over the rest of the summer depends, on the one hand, on how long it stays hot and, on the other, on whether we get a more or less normal amount of precipitation," says Marx. In places where there has been a lot of rain and the soil is well moistened, there is a buffer. "In some places, the buffer is so large that the water supply will certainly last at least until August." In Brandenburg, for example, the soils are so wet that they could easily survive a two-week heat wave.

Soils can store large amounts of carbon, purify water, are an important source of nutrients for plants, and are essential for feeding the world's population. Healthy soils with a balanced pore structure absorb water like a sponge and release it when needed. However, many are in poor condition due to land sealing, intensive agriculture, and climate change. According to the "Soil Atlas" published in 2024 by the Heinrich Böll Foundation and the German Federation for the Environment and Nature Conservation (BUND), more than 60 percent of soils in the European Union are considered damaged.

Has the rain been able to offset damage from past dry periods in Germany? "No," said Marx. "For the entire soil to be sufficiently moist up to a depth of two meters, it takes at least three very wet months."

And what about the groundwater? "In places where it has rained heavily, for example, east of Berlin, in the Barnim district of Brandenburg, some groundwater levels have risen significantly." Regions where the groundwater is relatively close to the surface are particularly benefiting. From a depth of 10 meters, there is little to no effect. However, the groundwater is usually replenished during the fall and winter months, explains the water researcher.

RND/dpa