Got herons? We have solutions!

Water Garden & Features Q & A

Q: Do great blue herons fly south for the winter? – Derek in Massachusetts

A: The bane of fishpond owners, great blue herons, will make a quick meal out of pricey koi and graceful goldfish. The good news is that those in the northern swath of the United States are about to enjoy their exit – at least for the winter months.

These birds are one of the most widespread wading birds in North America. While herons’ breeding range stretches from the southern Canadian provinces to southern Mexico, their wintering and permanent range extends from southeastern Massachusetts along the coastal states and west across the southern half of the United States, and into Mexico and northern South America. So when the temperatures dip, they prefer to fly south to the warmer climates.

If you live in the northern regions of New England, the Great Lakes, the Northern Plains and regions that freeze during the winter, you will see the herons fly for warmer skies. Experts report the birds migrate south from the northern portions of their breeding range beginning in September and October, with their return in mid-March.

For those who live in great blue herons’ wintering and permanent range, you’ll unfortunately enjoy no wintertime respite from these sushi-eating birds. Here are some ways to keep your fish safe:

Install pond netting: A near-invisible barrier, pond nets, like the Atlantic® Pond Protector Net Kit, prevent the birds from landing in your water feature and spearing your fish. They also keep fall leaves from turning your pond into an over-sized tea pot.

Put up a decoy: Because herons are territorial, you can place a heron decoy near your pond to dissuade others from landing. Be sure to move it periodically to keep up the appearance of a live bird.

Spray the birds away: Motion-activated scarecrow devices, which shoot a 35-foot blast of water at any animal that breaches its sensor sweep, make excellent deterrents for not only heron, but raccoon and other predators, too.

POND TALK: What do you do to deter herons from landing in your yard?

Allow harmful gases to escape by adding a diffuser.

Water Garden & Features Q & A

Q: How do I prepare my fish for winter? Do I need to bring them inside? – Liz in Michigan

A: As the temperatures fall, we may be pulling out our winter coats and goulashes, but your fish don’t need them at all! In fact, pond fish, like koi and goldfish, do quite well in a pond over the winter – even if it freezes over – as long as your pond is at least 18 inches deep (though we recommend 24 inches to be certain the fish don’t turn into popsicles). The fish will go into their annual torpor, or dormancy, and will require little more than clean, oxygen-rich water to survive.

To ensure they get that life-sustaining oxygen, you will need to do four things:

1. Remove debris from the pond. In the fall, before ice forms, give your pond or water feature a good cleaning. Rake out debris, trim dead leaves off plants, net floating leaves and remove as much detritus as possible so very little will be decomposing – and releasing harmful gasses – through the cold months.

2. Add some beneficial bacteria. Also in the fall, you may want to add some beneficial bacteria, like Pond Logic®’s Seasonal Defense®. It accelerates the decomposition of leaves, scum and sediment that builds up during the fall and winter months. In the spring, it replenishes winter bacteria loss, jump starts the filter and breaks down unwanted waste, making your pond water ready for a clean spring and summer.

3. Install an aerator or air stone. Colder water holds more oxygen than warmer water, but you’ll still want to inject air into the pond during the winter months, especially if your pond freezes over. One or two air stones or a diffuser placed in a shallow part of your pond will be enough to aerate the water and keep a small hole in the ice, which will allow harmful gasses to escape and oxygen to enter.

4. Hook up a heater. If you live in a frigid area where the ice on your pond builds to an inch or more, you can use a floating heater or de-icer, like the Thermo Pond, that melts through the ice. Again, it’s critical to keep an open hole in the ice to allow for gas exchange.

In most cases, your fish will be just fine through the winter months. When the water warms, you can begin feeding them again and enjoying them for yet another year!

POND TALK: How do you prepare your fish for winter?

Picture of Pond Netting Over a Water Garden.

Q: My water garden is placed by a tree and a ton of leaves collect in my water garden. It is a real pain cleaning the pond out at the end of the year. What can I do to prevent leaves from coming in? – Matt of Pennsylvania

A: This is definitely an issue that should be addressed. By preventing leaves from entering the pond, you will help reduce the “muck” build-up, allowing for less pond maintenance.

Using Pond Netting to Keep the Leaves Out: A simple solution to keeping leaves out is to place a pond netting over your water garden. Most pond netting will come with their own stakes that can be used to keep the net in place. This is by far the best and easiest way to accomplish this.