Article written by Madeline Wimmer, Extension Educator - Fruit Production
Birds are often the most damaging wildlife vineyards face. Bird pressure can change depending on a vineyard’s location and how close it is to a forest edge, or a grainfield that attracts birds after it's harvested.
Other variations that contribute to bird pressure include seasonal trends, the grape variety, and bird species (i.e., not all bird species feed on grapes). When bird damage is severe, it can be devastating to a particular vintage.
Thus, taking time to prevent the damage can ensure a quality harvest. There are a number of different methods to either exclude or deter birds, including sensory deterrents and netting, which are typically installed around veraison or slightly closer to harvest time, depending on the vineyard location and circumstances.
Mesh sizes for bird netting can range from ½–¾ of an inch—larger than most hail netting. Materials used to make netting also vary, as some netting types are slightly rigid, while others are softer.
The type of netting material used and the netting width change how it is applied and how it can be stored. Plastic mesh netting tends to be fairly rigid, although it's flexible enough to roll onto a spool for storage. Knit/drape netting can still be made from plastic, but because it is woven, it is more flexible.
Image: Plastic mesh netting can be stored as a spool. In the vineyard in this photo, the netting was clipped to PVC tubing and rolled up using either a forklift or attached rebar and a handmade crank fitted to the PVC tube. Photo taken at Cambridge Winery located in Cambridge, Wisconsin (Zone 5b).
Depending on its width, plastic mesh netting can either be installed over the top of a canopy and clipped underneath the vines, or as two separate half nets, one for each row side.
Because of how rigid this type of netting is, it does not bunch well and is usually wound up for storage. For vineyards that have rows with different lengths, organizing this type of netting with clear labels indicating net/row lengths will save time when installing netting the following year.
Drape netting can be installed with a netting mechanism like a Netter Getter, or handcrafted option that pipes the netting through a tube and optionally a guide or cage to stretch it over the row. Some methods will require more people to get the job done well and quickly. Nets can be clipped immediately after or during installation underneath the vines to keep it in place.
Tactics that use sound include bird distress calls, predator recordings, and sound cannons, which alarm and confuse birds. Visual deterrents—often shiny, or mimicking the appearance of predatory birds—also exist and can be placed strategically around the vineyard to scare birds.
These alternative methods vary in price, but usually require much less labor to install. They also vary in how effective they are at deterring birds, as some birds may adapt and become indifferent to methods that were initially alarming to them.
More recently, other options have been available to deter birds like lasers, which are sometimes referred to as “laser scarecrows.” These tools are still in development, as technology like species recognition is being researched and integrated into future models.
Images: 1a) Rigid, plastic mesh netting with 3/4in mesh demonstrating how netting can be lifted and temporarily clipped above clusters to make harvesting easier; b) close up showing a yellow garden spider for size comparison; c) netting clips can fasten any type of net and can be clipped below grapevines. 2a) An alternative over-the-row knit mesh netting is more flexible, can be applied mechanically (2b), and can additionally be clipped underneath vines to keep it in place.
Birds are often the most damaging wildlife vineyards face. Bird pressure can change depending on a vineyard’s location and how close it is to a forest edge, or a grainfield that attracts birds after it's harvested.
Other variations that contribute to bird pressure include seasonal trends, the grape variety, and bird species (i.e., not all bird species feed on grapes). When bird damage is severe, it can be devastating to a particular vintage.
Thus, taking time to prevent the damage can ensure a quality harvest. There are a number of different methods to either exclude or deter birds, including sensory deterrents and netting, which are typically installed around veraison or slightly closer to harvest time, depending on the vineyard location and circumstances.
Bird netting
Using nets as a physical barrier to exclude birds from reaching the grape clusters is still often considered the most reliable way to prevent bird damage.Mesh sizes for bird netting can range from ½–¾ of an inch—larger than most hail netting. Materials used to make netting also vary, as some netting types are slightly rigid, while others are softer.
The type of netting material used and the netting width change how it is applied and how it can be stored. Plastic mesh netting tends to be fairly rigid, although it's flexible enough to roll onto a spool for storage. Knit/drape netting can still be made from plastic, but because it is woven, it is more flexible.
Plastic mesh netting
Depending on its width, plastic mesh netting can either be installed over the top of a canopy and clipped underneath the vines, or as two separate half nets, one for each row side.
Because of how rigid this type of netting is, it does not bunch well and is usually wound up for storage. For vineyards that have rows with different lengths, organizing this type of netting with clear labels indicating net/row lengths will save time when installing netting the following year.
Knit/drape netting
Knit/drape netting is usually made from yarn or high-density polyethylene. Its woven nature allows it to bunch much easier than plastic mesh netting. It can be stuffed into sacks or spooled for storage at the end of the season.Drape netting can be installed with a netting mechanism like a Netter Getter, or handcrafted option that pipes the netting through a tube and optionally a guide or cage to stretch it over the row. Some methods will require more people to get the job done well and quickly. Nets can be clipped immediately after or during installation underneath the vines to keep it in place.
Preparing for netting installation
- No matter which type of netting you choose to install, remember to wear buttonless shirts when installing and removing netting. Buttons can catch onto netting frequently, slowing down the process.
- Drape netting: Decide if you are going to cut individual pieces of netting for each row, pull it in between rows, or something else. Be strategic and keep track of netting pieces with labels.
- Hold onto cardboard tubing, or create your own spools out of PVC and a crank to store plastic mesh netting.
- Find stuffing sacks of the appropriate size for storing knit/drape netting.
- Plan ahead for the time and labor needed to install netting. The job can usually be done faster with more people, when available.
- Equip yourself with clips that can bridge above and below two-sided plastic mesh netting, or clip drape netting under the vine canopies. Netting is prone to blowing off vineyard rows without clips. Securing nets is especially important in windy vineyards, which is common across the Upper Midwest.
Additional bird deterrent options
A number of innovative options have been developed that take advantage of sensory distress to deter birds. These can be used in addition to or as an alternative to netting.Tactics that use sound include bird distress calls, predator recordings, and sound cannons, which alarm and confuse birds. Visual deterrents—often shiny, or mimicking the appearance of predatory birds—also exist and can be placed strategically around the vineyard to scare birds.
These alternative methods vary in price, but usually require much less labor to install. They also vary in how effective they are at deterring birds, as some birds may adapt and become indifferent to methods that were initially alarming to them.
More recently, other options have been available to deter birds like lasers, which are sometimes referred to as “laser scarecrows.” These tools are still in development, as technology like species recognition is being researched and integrated into future models.
Ultimately, think about your specific needs and situation, along with the resources you have available when creating a plan to deter birds. Most supplies are available through online vendors. The more planning you put into the process beforehand will help streamflow netting for this and coming years.
Additional reading:
Additional reading:
Comparing bird management tactics for vineyards and berry crops (University of Minnesota Extension publication)
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