Alleyway cover-cropping in blueberries

Project lead and post author: Carly McGregor

Insect species such as pollinators and natural pest predators can support crop growth; however, they are especially impacted by habitat loss due to agricultural intensification. Alleyway cover-cropping is an emergent habitat amendment technique that can support these beneficial insects on farms by providing floral and/or nesting resources through the addition of functional plant species between crop rows.

In 2023, we conducted pilot trials for a selection of functional flowering plants, including self-heal Prunella vulgaris, phacelia Phacelia tanacetifolia, and sweet alyssum Lobularia maritima, within cover crop blends (ryegrass and red clover) to measure establishment success and feasibility for future alleyway plantings. The self-heal seeds did not germinate in the first establishment year, but phacelia and sweet alyssum established successfully.

Starting in 2024, we have been piloting our alleyway cover crops at the UBC farm’s blueberry crops, and investigating the success of this technique in supporting pollinators and natural enemies of pests. We have included phacelia P. tanacetifolia and sweet alyssum L. maritima in our trials, since they were successful candidates in 2023, as well as red clover Trifolium pratense, since it is commonly used in cover cropping and is a good foraging resources for bees. Finally, we have included peppermint Mentha x piperita for its potential to repel SWD and since it may be a good foraging resource for parasitoid wasps and pollinators. 

This project specifically investigates whether alleyway cover-cropping can be a relatively accessible practice that can support beneficial insects in blueberry crops. This project will serve as a pilot for the use of alleyway cover-cropping as an ecologically-intensive management technique that may sustainably support crop pollination, biological pest control, and agro-ecosystem health.

To cite: McGregor, C. (Year, Month Date). Alleyway cover-cropping in blueberries. PIEE Lab website; [page web link].