(OPPENHEIM, GERMANY) - There’s more than grape vines growing in the organic and biodynamic vineyards of Germany’s Rheinhessn - there’s a virtual smorgasbord of plants for bugs and birds between the rows.

Some people might call them weeds, but in Germany they say “herbs” and at many stops along the way during my recent exploration of the world of biodynamic and organic wine, they turned up on my plate, too.

The tasty and aromatic herbs and flowers - calendula, sweet vetch, yarrow, blue chicory and golden tansy - grow in mixed profusion in Germany’s organic and biodynamic vineyards, where tidy trellised vines coexist with indigenous plants.

We checked in with Professor Randolf Kauer at the famous Geisenheim Research Centre, who is the only professor of organic and biodynamic wine growing in Europe. With his students, Kauer is tending experimental biodynamic vineyards, and making experimental batches of wine (some 200+ permutations per season) to see if there’s any scientific basis for Rudolf Steiner’s popular biodynamic theories. Like Steiner, biodynamic growers work with nature, planting and harvesting according to the phases of the moon, treating the plants with homeopathic preparations and feeding the soil with organic fertilizers and cover crops. It’s all designed to create a harmonious natural ecosystem instead of a typical agricultural monoculture.

Many winegrowers - especially the growing number of converts in Germany and France - are convinced that this kind of farming creates healthy soil and plants, and wines with flavours that truly reflect their specific vineyard terroirs.

It was the cover crops that blew me away - virtual forests of wildflowers clogging the rows. Kauer explained that the cover crops not only work above the ground, attracting butterflies, bees and other beneficial insects, the intricate pattern of roots from each different plant, work through the soil to keep it aerated and healthy for all kinds of organisms to flourish. In fact, there’s literally a forest of roots, as diversified and unique as the various yellow, red and white clovers, lentils, caraway and yarrow growing above ground.

What’s best to plant between the vines? That depends on how much rain you get (cover crops can rob moisture from vines in dry areas) and what the soil needs, but they are experimenting with different mixtures of wild plants. At Weinbut Bruder Dr. Becker, Hans Pfeffer-Mueller showed us some of the various seeds he includes in the mix - from clover  to tansy - and his wife Lotte Pfeffer-Mueller, who chairs the board of ECOVIN (Germany’s largest association of organic wine growers), tossed many of the flowers and greens into a tasty salad for our lunch.

Angela Kuehn of the full biodynamic Weingut Peter Jakob Kuehn explained that they seed mixtures of up to 60 different “herbs” which  bloom in different colours “to signal the bees that they should visit us.” After the plants have bloomed they are “laid down” in the rows to form a mulch which prevents moisture loss and erosion, and which is turned into the soil to nourish it later.

So is there any scientific basis for Steiner’s biodynamic preparations, the horn manure, diluted compost and plant teas that are sprayed at various times during the season to energize the vines and soil? After four years of study, Kauer says his experiments show that spraying the diluted “manure” that’s been composted in a buried cow’s horn does in fact help create a strong soil with lots of earth worms, humus and ability to retain water.

Kauer admits its hard to quantify Steiner’s theory that spraying homeopathics can take “light forces” to the plants but “we can see in out field trials that it works.”

“Now we have to see why.”