Water march: Eco-friendly irrigation in the sustainable garden

The last two years went down in history as drought summers. There is too little rain in extensive parts of Germany in 2020 as well. Efficient water management thus plays an increasingly important role in gardens.

The garden blogger from Cologne, Beatrice Degenhart, occupies herself intensively with the topic. She is taking care of the project garden that was created this year on behalf of spoga+gafa. Sustainability is one of the priorities here, because this aspect is to be one of the special focuses of the international garden trade fair that is being staged at the end of May in 2021.

Up until the trade fair, Degenhart will regularly report from and about the show garden via the social media and will highlight various aspects of an environmentally-friendly garden design, give tips on resource-saving management and will present many sustainable and innovative garden products.

"We should fundamentally be very sparing with the vital resource water – this also applies in private gardens," said Degenhart. "Here the consumption can among others be significantly reduced by the corresponding planning regarding which plants should be grown. Hence, for the project garden I have primarily selected plants that have a low water requirement and which survive dry periods well."

Modern irrigation technology as well as collecting rainwater significantly reduce the consumption in the garden too, the blogger explained and outlined a further advantage: "People, who use rainwater for watering the plants are not only being kind to the environment, they also save a lot of money. A rain barrel should thus belong to the standard equipment of every garden. Most of them hold a capacity of 200 to 600 litres. For a small garden like ours, it is totally sufficient to conduct the rainwater from the roof of the garden shed into the rain barrel, as we have done. The specialised trade does however also offer larger tanks. Incidentally, further options are available in addition to the classic round and green rain barrels. There are many different shapes and colours to suit all tastes – for instance models that look like big amphorae or ones that are covered with wood. Of course, nearly all of them are largely made of plastic, whereby some manufacturers already rely on recycled materials for their production.

And a further tip from the expert: "Those who want to prevent the rain barrel from overflowing in the case of strong downpours, don't just let the downspout from the roof gutter end in the rain barrel, but implement a so-called rain collector instead. This is a hose connection which guides the water from the downpipe laterally into the barrel. Once this is full, no more water is conducted into it. Such rain collectors have further advantages: The rain barrel can be sealed with a lid on top so that no leaves can fall in and so that gnats can't use the water as a breeding ground."

When redesigning their garden, owners of a large plot should also consider whether it might not be worth investing in a rainwater cistern that is embedded into the ground. Building a well to use the groundwater for one's own greenery is also a sustainable option of saving drinking water. Depending on the respective function the well is to fulfil in the garden, there are different types to choose from. Whereby it is definitely recommendable to inform oneself in advance whether extracting the groundwater is at all permitted in the respective region.

Of course, the implementation of water pumps is above all advantageous in the case of cisterns and wells. They conveniently transport the water to the place where it is needed. "But there are also electric rain barrel pumps for the owners of smaller rain barrels, who don't want to cart watering cans around. They are offered both with a mains supply or with a battery pack," Degenhart explained. "This enables the collected water to be distributed in a simple way using the garden hose. These can also be equipped with different attachments - sprays, sprinklers or spray lances. This is not only practical because one can more readily control which part of the garden is watered more intensively and which less intensively, but water is also saved as a result! Incidentally: One should essentially always water the plants in the morning or in the evening, so that the precious water doesn't evaporate as quickly."

"Sustainable gardening doesn't mean that one has to carry out as much of the garden work as possible using traditional methods and one's own physical strength," Degenhart explained. "Modern irrigation technology is by all means eco-friendly and assists in effectively saving resources. Furthermore, it also ensures that the plants are provided with precisely the amount of water they need." For example, drip irrigation is a good choice for many garden areas such as flower beds and vegetable patches or hedges. It is however also suitable for balcony flower boxes, terrace plants or greenhouses. Thin, plastic tubes with openings in different places are laid across the surface. The water is transported to the selected plants drop for drop at regular intervals. There are several executions of drip irrigation systems. In addition to microsprinklers and on-line drippers that are installed above the ground, there are also in-line drippers that can be laid under the ground. "A dripper is being implemented in the flower beds of the project garden, which was placed at our disposal by the company Fiskars," the garden blogger explained. "It was originally 15 metres long and could simply be cut down to the required length using a pair of scissors. We simply placed it on the ground and secured it using the supplied metal hose clamps. But one could also have buried it."

The control equipment is an essential element of such an automatic irrigation system. Here a water timer or a small computer is placed directly in-between the tap and the hose. As a rule, the appliance is equipped with a display that can be used to programme the desired irrigation times and intervals. Degenhart noted: "High-quality models can be enhanced by sensors, which constantly measure the soil moisture, sunlight and temperature for instance and based on this data calculate the exact water requirement of the plants and supply them accordingly. As such, as far as irrigation is concerned one doesn't have to do a thing anymore. However, it is important to bear in mind that drip irrigation systems should only be operated using clean water and that the water computer requires an extremely consistent water pressure.”

The right and well-conceived water provision of the plants not only plays an important role in the garden, but also for potted plants. For example, the blogger grows her herbs in the flexible plant receptacle system, NatureUp!, which the company GARDENA made available for the spoga+gafa project garden. Even if only a small surface is available on the balcony or terrace, it offers room for a host of plants. The system can be expanded in a modular fashion, can stand on the ground or be attached to the wall. The micro drip irrigation system, AquaBloom, also from GARDENA, provides the optimum water supply drop by drop. Neither an electrical supply nor a water connection is required. The pump and the control unit are battery powered, which are charged using a solar module. The water is drawn from a bucket or a barrel.

"There are a host of very different options of keeping one's garden well irrigated in a resource-saving manner. Each garden owner has to find out for himself which is the best option for the respective garden situation," Degenhart stated. "In most cases, the right answer is probably a combination between different options.

More on sustainable gardens and the garden project of spoga+gafa can be found in the blog of Beatrice Degenhart: beatricedegenhart.de