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Planting and maintenance of perennial flower strips and flower beds with native wild herbs

Over the past few centuries, agriculture has created diverse and, in many places, highly species-rich cultural landscapes. However, this diversity is now under threat due to increasingly intensive and extensive agricultural use. In Saxony-Anhalt, too, a steady decline in many plant and animal species has been observed in recent decades.

In order to support the positive development of biodiversity, agri-environmental and climate measures (AUKM) are being offered in the federal states as part of the Common Agricultural Policy (CAP). In Saxony-Anhalt, for example, the creation of perennial flower strips with native species is being promoted in 2014-2020.

In the last funding period, perennial flower strips were mainly planted with conventional mixtures of short-lived and a few perennial crops, which usually developed into vegetation dominated by grasses or ruderal species with few flowers from the second year onwards.

In a collaborative project between Anhalt University of Applied Sciences and the Saxony-Anhalt State Office for Agriculture, Forestry, and Horticulture, an experiment was therefore set up in 2010 with various mixtures of native species. The aim was to develop species-rich mixtures for long-lasting and intensively flowering stands with high ecological value that would last for at least five years. In addition, maintenance should be possible within the framework of the funding guidelines and also practicable for farmers.
In July 2013, Saxony-Anhalt’s Minister of Agriculture and Environment, Dr. Hermann O. Aeikens, is visiting the trial (photo: Renate Geue).

Project priorities

A 168 m x 10 m block trial with 7 variants and 4 replicates was set up on farmland in Bernburg-Strenzfeld, Kohlenstraße: 3 wild herb mixtures (25-32 species; H1-3), 3 wild herb mixtures with cultivated species (22-36 species; F1-3) and 1 conventional crop species mixture (9 species, FK). After careful seedbed preparation, 3 variants were sown in September 2010 (H1-3) and 4 variants in April 2011 (F1-3, FK). Due to the small quantities of 0.7–2.0 g/m², the wild plant seeds were stretched to 10 g/m² with a filler (soybean meal). Sowing was carried out with a seed drill with the coulters raised so that the seeds were only deposited on the surface, as many of the wild plants are light germinators. The area was then rolled.

Project region

Saxony-Anhalt

Further project details

  • In the first year of development, species that spontaneously migrated from the soil or the surrounding area accounted for a relatively high proportion of the total number of species and total coverage on all variants. While the coverage of spontaneous species declined sharply on all variants rich in wild herbs from the second year onwards, their coverage on the conventional variant remained above 50% in all years. Due to the failure of cultivated species as well as annual (e.g., corn poppy, field larkspur) and some biennial (e.g., dyer’s rocket, mullein) wild herbs, the number of seeded species on the plots decreased over time. In the summer of 2014, 87-100% of the perennial wild herbs were still present on the wild herb-rich variants. From the second year onwards, the sown species achieved a coverage of over 90% on all wild herb-rich variants

    Das Blütenangebot entwickelte sich auf den wildkräuterreichen Varianten ebenfalls sehr positiv. Im ersten Untersuchungsjahr kamen zwischen 9 und 22 Ansaatarten zur Blüte; dies entspricht etwa 50 – 90 % der aufgelaufenen Ansaatarten. In den Folgejahren stieg dieser Anteil auf über 90 %, wodurch, je nach Variante, zwischen 23 und 34 blühende Wildkräuter auf den Flächen vorhanden waren. Bei der konventionellen Ansaatvariante konnten sich im 1. Jahr nur drei der angesäten Arten etablieren, die zwar alle zur Blüte gelangten, aber nur sehr geringe Deckungen von max. 5 % erreichten. Im vierten Standjahr war nur noch eine blühende Art (Rot-Klee) aus der Ansaatmischung mit einer mittleren Deckung von 1 % vorhanden; die Vegetation der konventionellen Variante wurde ab dem 2. Jahr von Gräsern (Wiesenschweidel, Rotes Straußgras) dominiert.

    Anzahl der Kulturarten, der ein- und zweijährigen sowie der mehrjährigen Wildkrautarten in den Ansaatmischungen und ihr Vorkommen im Sommer 2014 auf den Varianten des Blockversuches. H1/F1 = Löß, H2/F2 = Löß/trocken, H3/F3 = Löß/niederwildfreundlich, FK = konventionell.
    Number of cultivars/ornamental plants, annual, biennial and perennial native forbs in sown mixtures and present in the variants of the block trial in summer 2014.

  • In many arable locations, relatively dense stands of undesirable ruderal species develop after sowing. Depending on the region, soil values, and moisture levels, development can vary greatly. If species such as goosefoot, amaranth, scentless chamomile, and Canadian fleabane occur in dense stands, the competitive pressure has a negative effect on the development of the sown herbs. During the development year, it is therefore essential to carry out mulch cutting at a height of at least 10-20 cm in good time, i.e. at the bud stage of the undesirable ruderal species (usually as early as May), taking care not to damage the young plants of the seeded species. In fast-growing locations, a second maintenance cut (June/July) may be necessary.

    As part of the development maintenance, mulch cutting was carried out at a height of approx. 15 cm on the Kohlenstraße block site in May 2011 and between June and July 2011. The biomass remained on the site. From 2012 onwards, the block trial was mulched once in mid-March and once between June and July (half each time, at 6-8 week intervals) as part of maintenance.

    Flower strips should be mowed/mulched in sections (early/mid-June and mid/late July), with an interval of 6-8 weeks between the two mowing dates. The clippings can be left on the ground. This ensures a continuous supply of pollen and nectar sources throughout the growing season and provides optimal refuges for hares and partridges, for example.

    Condition of the block experiment one week after the half-side mulch cut in mid-June 2013 (photo: Matthias Schrödter).

  • Based on the results and experiences of block trials and other practical applications, five mixtures for the establishment of perennial flower strips were developed in Saxony-Anhalt for the new agri-environmental and climate measures. The mixtures consist exclusively of native wild herbs from certified sources. Cultivated species are not used, as autumn sowing is recommended in the dry regions of central Germany. Due to the maintenance measures required in the first year to suppress field weeds, it is also better to avoid annual cultivated species, as these are usually not suitable for cutting and their presence often leads to necessary maintenance cutting being delayed for too long.

  • Practical guidelines have been developed for the successful creation and maintenance of perennial flower strips. These guidelines are intended to support farmers, other users, and institutions in their efforts to create species-rich flower strips and areas that will bloom colorfully for many years to come.

    Suitable locations

    Open fields and the south side of hedges, rows of trees, or forest edges are ideal. Shaded and permanently wet locations are unsuitable. The selected areas should be free of perennial problem species (e.g., creeping thistle or couch grass) and neophytes.

    Date of investment

    Autumn sowing from August to mid-September (especially in regions with spring drought); spring sowing until mid-April.

    Seed mixture and sowing density

    In Saxony-Anhalt, there are five mixtures of 27-30 wild herbs of certified origin as part of the agri-environmental measure “Perennial flower strips and areas”: (1) loess-loam, fresh, (2) loess-loam, dry, (3) sand, fresh, (4) sand, dry, (5) moist locations. The pure seed quantity is 0.4-0.5 g/m².

    Seedbed preparation and sowing

    Careful seedbed preparation is important. The seed mixture should be mixed with a filler to 10 g/m² (e.g., soybean meal, crushed corn) to prevent segregation. Sowing can be done with seed drills with the coulter raised. Important: the seeds should only be placed on the surface (light germinators!). For optimal soil contact, rolling should be carried out after sowing.

    Development support (in the first year)

    If weed pressure is high, the areas must be mowed or mulched to a height of at least 10-15 cm in May and, if necessary, in June/July, while the weeds are still in the bud stage. The biomass can remain on the area.

    Follow-up care (from the 2nd year onwards)

    To ensure year-round flowering, the areas must be mowed/mulched in sections (e.g., in halves) at a height of approx. 15-20 cm (between the end of May and the end of July). In productive locations, further maintenance mowing may be necessary at the end of winter (March). The biomass can remain on the area.