Monday, August 1, 2022

Vineyard Ground Crop Cover

Storks Bill which can create a lovely carpet of tiny purply-pink flowers early spring is one of the commonly planted vineyard cover herbs here in our Okanagan vineyards.

As our BC wineries and viticulturists find workable solutions to the effects of climatechange, we are beginning to see a much wider use of cover crops in our vineyards. Vineyard cover crops can contribute immensely to the health of the soil, including water retention, contributing to drought resilience by increasing soil organic matter (over time), increased water infiltration and water holding capacity. Additionally they can deposit and set additional nutrients into the soil while assisting in nutrient cycling. For instance, clover and other legumes can set much needed nitrogen into the soil, which the vines can later make use of. Soil erosion is also reduced with the use of cover crops and with many of our Okanagan vineyards planted firmly in an ever so delicate silty, loamy, bench land soil... a type that drifts away with the lightest disturbance, it is a good thing!

Flowering cover crops can attract beneficial parasitic insects that prey on vineyard pests. By increasing their habitat we can draw them into the vineyard as well as attract vertebrates that can assist in rodent population in and around the vineyards (another pesky Okanagan issue). With the advent of chemical pesticides, unfortunately, the benefit of pest control with natural parasitic insects has long since been forgotten. There are some very interesting ongoing studies that link the conservation of natural habitat with reduces pest problems in winegrowing areas. Hopefully soon we will see the use of inter-vine mulching as an alternative to spraying glyphosate which we are now finding can reduce cold hardiness in some vine species and cause issues that have long been attributed to frost damage, like trunk die back due to trunk splitting. Perhaps the world could use a little less of it. New tractor attachments called finger weeders that go in and around the vines sort of grubbing up all the weeds, are a great alternative. David and Cynthia Enns, of 1Mill Rd have one in use now, and I am certain we will see more of them in use. Step by step, our growers continue to rise to the occasion!

By Wendy Vallaster