Background: As agriculture has intensified, many once-common wildflowers have declined in arable landscapes, which has widespread implications for associated ecosystem services. The incorporation of sustainable practices, for example, growing living mulches (in-field, non-crop plant ground cover, maintained during the target crop growing season), can boost arable biodiversity, but few wildflower species have been utilised in this context. 

Aims: Our aim was to determine the suitability of arable wildflower species, once considered weeds, for use as living mulches.

Methods: We first screened a number of arable wildflower species for germination when growing with a common cereal, barley (Hordeum vulgare). We then grew two (Centaurea cyanus and Scandix pecten-veneris) in pots in a glasshouse with and without barley, and grew barley alone to test the impact of the wildflowers on barley growth and biomass.

Results: Neither of the wildflowers significantly negatively impacted barley biomass. Barley initially facilitated germination in S. pecten-veneris, but ultimately suppressed the above-ground biomass of both wildflowers. However, both wildflower species were able to coexist alongside barley.

Conclusions: Our experiment provides evidence that wildflowers that were considered weeds in traditional agriculture have the potential to be grown alongside barley and could be incorporated as part of a living mulch.

Sixteen wildflower species were sown in monoculture or alongside barley in a sandy loam substrate. Germination was monitored daily for 30 days.Two wildflower species were chosen for a further experiment (Centaurea cyanus and Scandix pecten-veneris). Seedds of these and barley Hordeum vulgare were planted into pots either in monoculture or in additive mixtures. Plants were grown and then one third of the pots harvested at 42, 92 and 162 days after planting. Above and below ground biomass were harvested and estimated at the first two time points. Above ground biomass was harvested and estimated at the third time point and fruiting material separated from the shoots. Data were anlysed to determine whether local environment (monoculture or mixture) influenced germination or biomass accummulation throughout the growing season.