Improve Harvests And Picking Ease In Blueberries
Pine/Orchard voles have been an ongoing control problem for us here at Crow’s Nest Farm, going back to the late 1970s and early 1980s when we first began planting blueberries. Left alone, especially on the outside blueberry rows near fence lines or wooded areas, they literally eat the roots off until plants can die and fall over from lack of support. Needless to say, such sub-surface damage to roots and crowns does not promote life or vigorous growth.
For years, in early October and again in late March or early April, we would walk the rows with a sharpened 1-inch dowel rod poking holes into established vole tunnels, then drop vole bait into these holes. Since we mulch heavily around and under each plant, the holes were most often punched between plants rather than under the plants. Then, fellow growers, good long-time friends, Tom and Arvella Stewart, five counties away down in Scott County, VA, near Bristol, called us with a problem. They were able to obtain discarded industrial filters in their area that they laid on the ground around young blueberry plants for mulch and weed control. However, they soon found, as Tom described, “condos” of voles had moved in under the shelter of the filter mats. They were removing the mats from their fields before voles destroyed their blueberry plantings.
Soon after their experience, a “moment of enlightenment” suddenly came to me: Why not cut these large mats into four smaller pieces of at least 1½ feet square or so, and lay them in-row midway between blueberry plants to actually entice the voles to come there? Then, in a few weeks when vole holes are beginning to be seen under the covers, place vole bait into the holes and place the mats back exactly as they were. We simply peel the edges back, one side, then the other, check for voles and bait if need be, then lay that side back down, with no need to remove the pad or shingle from its place.
To prevent wind from blowing the mats out into row middles, we have had very good results placing the center of the mats beneath our heavy drip line that runs down each row on top of the ground. From Tom and Arvella we obtained a good starting supply of the filter mats, but after using all of them, we purchased bundles of discontinued roofing shingles that work very well. Each one can easily be made into two mats by folding them over end to end, then breaking them apart at the fold. Shingles are heavier, thinner, stay in place better in our high winds, and are waterproof to protect bait from the weather.
We place these covers in the rows under the drip lines in mid-summer, bait a few weeks later, and then again in October. By October, we see new vole holes as they are moving into the rows, especially the outside rows, from adjacent areas, particularly near fence-lines each fall. This method not only brings the voles to the bait, but also keeps the bait away from birds, rabbits, other animals, and the blueberry plants, too. The best part for us: No more dead, falling-over plants, plus renewed plant vigor with faster-growing, taller, young, new stem growth on our blueberries, along with improved yields and income.
Another management technique beginning in August each year that works for us is to remove “droopers,” blueberry stems that grow out and bend over along the sides of the plants. We prune these off after harvest season, usually in August for earlier ripening varieties, before the plants use energy to make fruit buds on these pendant stems we would prune off anyway in the winter months. Why have our plants waste energy? Why not allow that energy to go into making vigorous fruit buds on wood that will be retained to bear next year?
That has continued to be our thinking here, and has improved our yields, our average berry size, and our income. How do we know? It seems we never have the spare time in August to completely finish this task, since we are also busy with late U-Pick blackberries as well as late summer primocane red and golden raspberries.
Those blueberry plants we do not get to until our normal winter pruning, including thinning of old canes and crowded wood within the plant, have smaller berries with many fruit down on or close to the ground. This low fruit is missed by the majority of our urban U-Pick customers. We strive to have our fruit right up in their faces because they are happier, have no back aches from bending, and will stay longer and pick more.
We believe the plants need a lot of photosynthesizing surface during the summer months, so we do not remove or thin old stems or interior growth at the time we remove the drooping, pendant limbs. You can overdo anything, so we strive to control ourselves and not get carried away with August pruning. Perhaps in the future we can ask some friends to help us with August pruning, trading them for blueberries they will pick the next summer. If they like that idea, maybe they also can come back to help with the winter pruning! People helping each other, a good thing in today’s world.