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Kärcher Municipal


On course for growth with chemical-free weed control

Competitive edge with sensor technology

27. October 2017

October 2017, Altenstadt/Hesse – The company Tiedemann Dienstleistungen GmbH from Altenstadt, Hesse (Germany) primarily offers chemical-free weed control in addition to area cleaning and graffiti removal. Owing to the steadily increasing demand, it has become more and more of the company's main activity in the last 10 years. Besides municipalities in Hesse, Tiedemann Dienstleistungen also works for many municipalities in Bavaria and Thüringia. Parking spaces, graveyards, public squares and bus stops, but also sports grounds, hard courts and tennis courts, as well as port and waterfront areas of various rivers and lakes, are kept free of weeds. The company now specialises in weed control using the hot water method of Heatweed (formerly Wave), which works with the patented sensor technology. The machines Sensor I and Sensor II with articulated steering are used here.

From the scuffle hoe to infrared and foam to hot water

Before the Hessian company committed itself to the hot water method, it tested all chemical-free methods, obtained information regularly at trade fairs and rented or purchased new products released on the market. At first work was still carried out with a scuffle hoe, then came an electric scuffle hoe, then infrared devices, which were carried or pushed by hand. When the contracts for weed control increased, a reverse cutter was purchased initially, then hot air devices.

"One disadvantage of the hot air method is the heavy dust formation, particularly on unsurfaced paths and roads. There I have the inconvenience to the local residents, as well as the high maintenance costs for the device. Clogged filters have to be replaced, etc. For the devices, which emit the hot air to the front, there is the danger, particularly in summer when the plants are no longer in full bloom, that leaves may catch fire", reports CEO Waldemar Tiedemann.

"The main problem, however, was that the heat travelled upwards. Then we didn't achieve an even control pattern and therefore needed something that works more into the ground." The company used hot water foam for a few years with success. But when more and more large areas incl. sometimes narrower and tighter paths, e.g. at graveyards, had to be treated, the area performance was no longer favourable. The work was too time-consuming and diesel consumption was too high. "Efficient, fast and manoeuvrable. And also affordable. For us these are the main requirements of a device for weed control in order to be able to guarantee the area performance", highlights Tiedemann. "Our attention was brought to hot water and we came to the conclusion that this method is the most suitable for us. Especially in terms of the price-performance ratio and the effectiveness, as no single method can keep up."

"Before I would have needed two men for one sports facility and 16 hours, today I need one man and maximum 4 hours for one sports facility. This is the real clincher for us."

Waldemar Tiedemann

Daily area performance of 15,000 square metres

The area performance is primarily based on the ground, customer requirements, climatic conditions and the location of the area. Is it an outdoor area with lots of growth and vegetation around the area or an area in the city centre? Is the service provider confronted with an acute area with old and very intense growth or a nursery area that is maintained regularly and therefore requires less effort? Tiedemann Dienstleistungen always takes a general look at the areas first before offering the customer a customised weed control concept. "In the first year there is always more intensive treatment, the following year the intensity can be reduced considerably", states Waldemar Tiedemann. The estimated costs are based on the treatment intensity, for larger areas, however, a cheaper price can be offered.

Ideally give the service provider an opportunity to get the area to be treated into a good condition, for example with the conclusion of a three-year contract. "Everybody benefits here: We can start in spring and offer the customer a well-kept look throughout the season and constant prices too." Area performances of on average 15,000 square metres can be achieved per day, for sports facilities the performance can be significantly higher. "With an ideally located water connection and if the sports facilities are close together, I have also managed 25,000 square metres per day", reports Tiedemann. "Before I would have needed two men for one sports facility and 16 hours, today I need one man and maximum 4 hours for one sports facility. This is the real clincher for us."

Constant hot water directly at the vegetation point

This area performance is made possible with the patented sensor technology that is installed exclusively in Heatweed devices. The sensors installed in the machine scan the ground and only set water spots where there are actually weeds. The sensor sends an impulse to an electric switch which opens a valve that closes again straight away after spraying the hot water. This way a considerable amount of water and energy can be saved and the work can still be done fast and effectively. "It is also favourable that no tracks are left on the gravel or water-bound paths after the application", adds the Tiedemann CEO. "Most importantly, however, is that the hot water runs down and attacks the plants directly at the vegetation point." The water is maintained at a constant temperature between 98 and 99.6 degrees. "Water is simply an excellent heat carrier and accumulator", explains the sales representative from Heatweed. "Between 95 and 99 degrees the cells in the plants are activated, send out a negative messenger substance, which is then forwarded to the next cell. The plant is gradually destroyed and we get into the root area. It is important to maintain the temperature. Below 95 degrees this effect is in fact not activated and at much higher temperatures the cells stick together and the negative messenger substance is not passed on."

"It is also favourable that no tracks are left on the gravel or water-bound paths after the application. Most importantly, however, is that the hot water runs down and attacks the plants directly at the vegetation point."

Waldemar Tiedemann

Side effects: Cleaning and sterilisation

According to Tiedemann Dienstleistungen GmbH, one pleasing side effect of the hot water weed control is the cleaning performance. Moss or lichens are also controlled and overall the surfaces look cleaner. Heavily contaminated and foul-smelling pedestrian underpasses or tunnels can also be cleaned with the machines. The pungent smell is instantly diminished with the application of almost 100 degrees hot water. Another possible application is washing clay courts and playgrounds including the play equipment. Sterilisation can also be achieved with the hot water on areas such as artificial grass. "The devices can be used not only for weed control", highlights Waldemar Tiedemann. To put it the other way round, high-pressure cleaners are indeed good for cleaning work, but they cannot keep their promise when it comes to weed control. "I can use the devices on a small area, but for an area of 30 or 40 square metres where I work non-stop I have shadows in my area", criticises Tiedemann. "The water is heated to 100 degrees via a heating coil, but then the temperature drops to 80 degrees, then it is heated again to 100 degrees. These temperature fluctuations are visible in the weed pattern of the area."

Hot water – a noteworthy alternative to herbicides?

The company development in relation to weed control is viewed extremely positively at Tiedemann. In all the years the use of herbicides has not been considered for several reasons. "The people want toxic-free, neutral weed control" highlights the CEO. "We are highly praised that we control weeds without herbicides." Besides the environmental aspect, the requirements for using herbicides are simply too high. The relevant employee would need a spray certificate. In addition, the day of the application must be approved in advance. If it rains on this day or there is strong wind, a new day must be approved. Also a facility cannot be opened for two days after spraying herbicides. Certain areas such as playgrounds or swimming pools are generally excluded from herbicide application. Municipal areas with special permits or exemptions are becoming less and less. Side effects such as cleaning the area or removal of algae and moss are also omitted. With hot water one can work almost independent of the weather conditions and there are no areas that cannot be treated.

"It's a clear 'Yes!' from us to the question whether the hot water method is an alternative to herbicides", confirms Tiedemann.