This month’s question came from multiple people; time to talk about it since it is a perennial problem for fruit gardeners everywhere. How can I keep birds off my grapes?
Bunch grape clusters are filling out right now and will start ripening soon. Muscadines form smaller clusters and follow the bunch grapes in the ripening sequence. Birds like the grapes slightly before they are ripe enough for us to eat. We can’t solve this problem by harvesting early because grapes do not ripen off the vine. They must remain on the vine until they are fully table ripe, and the window from ripe to overripe is fairly short.
First off, let me say that it is not easy to defend your grapes from hungry birds, but it is doable. I have tried several solutions, each solution with its own advantages and drawbacks. Let’s discuss a few options; then you can select the one that seems best for you.
Bird netting has been the go-to solution for years, and nets work fairly well. But some birds, especially mockingbirds, seem to find their way in anyway, and once they do, they can decimate a crop quickly.
You can run into troubles if you drape the netting directly on the vine. The birds can still see the grapes and they can often find a way to reach through the net to harvest them. You can also end up with a tangled mess of net, vine, leaves, and tendrils that will be frustrating to deal with after the harvest.
If you want to use netting, make sure it is sized properly – ¾” will stop most birds, but ½” stands a better chance against our smaller birds. It’s also best to install T’s made of PVC pipe or 2×2 lumber that stand OVER the vines so the netting can be draped over these T’s where it won’t tangle with the vines. And make sure to remove it immediately after harvest. The nets serve no purpose other than protecting fruit. Leaving it for even a week or ten days can make the task of removing them more difficult.
Another issue facing home fruit growers is that our grapes are not always on standard, straight-row grape trellises. They are often on arbors, ornamental trellises, pergolas, or patio covers. Grapes on these structures are almost impossible to net. We need other options.
Shiny metallic tape and spinning pie pans are often recommended. But as soon as the birds figure out that they aren’t a real threat, they help themselves. I haven’t found that they are very effective for grapes. Mechanisms designed to make noise or spray water interrupt the serenity of the garden, so for me they are not an option. Plus, many of us are using grapes in multiple places in our landscape and we would need too many gadgets to cover them all.
Last year we started using a method adapted from organic apple growers – paper lunch bags. These bags come in large quantities – 100 to a package. They are very inexpensive and infinitely disposable in the compost pile. Even though they are lightweight paper, they do withstand normal rainfall for the time period they will be on the vines. They take less time to install than a net and there is no post-harvest hassle. They also allow the clusters to breathe.
To install the bags you will need a stapler. If you can get one with a narrow nose it is easier, but any hand stapler will do. Just slide the bag over the cluster until the top edge of the bag is over the stem of the cluster. Center the bag and staple one side close to the stem. Slide the stapled edge tight against the stem, and staple the other side. That’s it. You would be surprised how quickly you can bag all of the clusters. Two people working together can do a vine in minutes. Once all of the clusters are bagged, your vine will look a little like you have hung a row of luminarias on it.
Don’t do this too early in the season; wait until the grapes are gaining size and you suspect they are ready for final ripening. We are just trying to dissuade the birds during the final ripening to table sweetness.
You can’t see through the bags to see ripening, but you can cut a slit in the bag to look for ripeness, and staple the slit closed again. You won’t have to check every cluster – as soon as one looks ripe, then you can start checking the rest. You can also leave a small cluster uncovered as a tell-tale cluster for when to start checking.
Yes, you can use this method on other fruits. The bags can be stapled over stone fruits and pome fruits. Stone fruits have a shorter stem than apples and pears, so some adjustment is needed, but it works. Ripeness on stone fruits can be tested without slitting the bag since you can feel when they begin to soften right through the bag. You will have to slit to check apples and pears, but it’s quick, and much more satisfying than having a basket of bird-damaged fruits.
The only drawback to this method is that it does not stop squirrels. If they get really curious they will tear the bags. But it does cut down on their curiosity – out of sight out of mind? One way or the other, we do find that it cuts down on their damage, too.
For berries and figs we still use netting draped over PVC T’s. They are just too prolific to make it practical to bag all of the fruits. However, if you need a few perfect figs for a special occasion dessert, you could certainly bag what you need. The bags can also be cut in half to suit smaller fruits and to extend the quantity. The cut end can be taped, glued, or stapled to form a new bottom.
One thing we have not tried is using kaolin clay. I am wondering if spraying the clusters would camouflage them from the birds. Kaolin clay is non-toxic and is used to deter insects and to provide a slightly reflective coating to cool trees down in harsh sun areas. I don’t know how hard it would be to wash off of a grape cluster but it comes off apples and peaches well with a cool water and vinegar wash. If it does as well with the grapes, it’s worth a try. I’ll let you know if it works.
If you have any questions about this blog, or have a question you think would be useful here, email me at [email protected].