What can you tell me about living mulches for blueberries?
Answer: There are numerous benefits to incorporating flowering cover crops into fruit production, including increased pollination, erosion control, and improved soil health. When it comes to your blueberries, I would recommend that you plant your living mulch in the 6-foot walkways between your rows. Research has shown that living mulch cover crops can actually compete with the fruit crop for water and nutrients if planted within the row. Even though legume cover crops will not demand much N from the soil system, they will still compete with the crop plant for water and other nutrients like P and K.In order to ensure that your blueberries have all the water and nutrient resources they need to thrive, I would recommend mulching the row with pine bark or hardwood mulch and planting your living mulch between the rows in the walkways, 18 to 24 inches from the center of the row. Having flowering cover crops within the walkway would still attract pollinators to improve the pollination of your blueberries, in addition to keeping the soil in place and feeding the soil foodweb. If you mow your living mulch, you could try to direct the clippings toward the blueberry row to add to the mulch and provide some organic N through the breakdown of the clippings. This “mow-and-blow” system can help build organic matter and provide N to the crop row without directly growing the cover crops there.When selecting cover crop species, I would recommend that you consider white clover, either Dutch White or New Zealand White. These white clovers can handle foot traffic and mowing and will bloom early in the spring, providing bee forage early on in the season. There is actually a great case study from SARE on a blueberry farmer in Michigan incorporating white clovers into his production system. You may want to select several varieties of clover and sow a cocktail to see which varieties perform best in your system. I would avoid any of the taller white clovers like Ladino, though. You can also find information on managing living mulches on our ATTRA website in a previous Question of the Week. There are some additional sources cited there, which you may find useful.