Deer Control with Psychology and Weed Control Strategies: This Weekend in the Garden

A small undertaking can defeat the deer

Research from Minnesota may give homeowners a new deer-proofing strategy: fenced gardens, which deer consider too small to safely enter.

The garden areas are called “micro-fences” and are created by creating 16-by-16-foot fenced areas using heavy-gauge galvanized metal cattle panels.

In two years of micro-fencing trials in a 60-acre “open” Minnesota forest with heavy deer pressure, deer grazed only once in 730 days of observations, said Kent Scheer, a farmer and forest owner whose land was used for the study by the University of Minnesota Extension, Green Island Preserve and Minnesota’s Regional Sustainable Development Partnership.

“This success rate is all the more impressive because these fences do not provide a physical barrier to deer entry,” Scheer writes in a post on the Garden Professors blog. “They are purely a psychological deterrent. That puts them in the same league as flashing lights, sound cannons, and water sprayers, but according to the data from this study, they are actually more effective.”

According to Minnesota Extension, micro-fences can be built using cattle panels that are 16 feet long and 50 inches high. They are widely available at farm supply stores.

Four of the panels are constructed into a square relationship by connecting three corners with cable clamps. The fourth corner is left unsecured so that one panel can be opened for access.

The test micro-locks were also secured using a six-foot steel post placed in the center of each panel.

Minnesota Extension believes micro-fences are based on the concept that deer avoid entering spaces that seem too small and risky to get in and out of quickly.

If this is the case, gardeners can overcome the deer problem by building one or more small, “point fenced” areas rather than fencing the entire garden.

This is good news for amateur gardeners who are trying to start small vegetable gardens, plant berry bushes, rare plants, collect deer-loving plants like daylilies and hostas, and maintain beds of young plants and seedlings.

Scheer says he was impressed by the low failure rate of the microlocks and the lack of maintenance required once they were installed.

“If deer do get in the way,” he says, “the solution is to simply make the fence look even smaller. You can do that by stretching a rope down the middle with a noticeable marking.”

Scheer says that based on the observations of micro-closures, “gardeners will do a much better job than by scattering human hair, planting garlic or buying ‘ultrasonic’ gadgets.”

Stay one step ahead of the weeds

Even though the worst of this season’s weed invasions are behind us, the beginning of fall is the best time to take steps to reduce the plague next year.

First, herbicides are most effective against perennial weeds at this time of year… assuming conditions aren’t so dry that weeds aren’t actively growing. Perennial weeds are winter-hardy weeds that grow back from their own roots year after year.

Perennials carry fuel produced by their leaves to their roots to ensure next year’s growth. This is a good time to introduce herbicides that can help with this process.

If you are a spray-based gardener, you will get the most bang for your herbicide buck by controlling plants like thistle, bindweed, poison ivy, hawkweed and goutweed in garden beds, and by spot-applying broadleaf herbicides to lawns like dandelion, ribwort, chickweed, spotted spurge and oxalis.

Each one can be dug up, which means instant death, does not pollute the environment, and is free.

Herbicides and digging/pulling are also effective this time of year against most annual weeds (those that live only a year). But because the frost will kill them in the next few weeks anyway, you won’t be able to get as much long-term control as you would with perennial weeds.

A better strategy for managing annual weeds is to focus on preventing them from causing new problems next year and in the years after that.

Most weeds have already flowered this season and are in the process of ripening their fruits and seeds now – if they have not already done so.

By killing or removing annual weeds now – or at least cutting off their seed heads before the seeds mature – you will prevent viable seeds from falling and spreading.

Some weeds/invasive species are capable of producing thousands of viable seeds per plant, including some that can live in the soil for 10 years or more before germinating.

Keeping all bare soil covered with plants or mulch is always a good defense to help prevent new annual weeds from germinating. Now is a good time to plant cover crops, and mulch can also be applied now if you don’t already have a two- or three-inch layer.

Some gardeners use granular weed killers to prevent new weeds from germinating. For example, Lebanon Seaboard Co., based in Lebanon, makes the popular Preen brand, which is available in a sustained-control formulation that is effective for up to six months against more than 120 weed species.

Although Preen and other weed killers don’t kill existing weeds, they can be used in garden beds where plants are already growing. (Check the labels for a list of approved plants.)

Early fall is also a great time to remove weeds and invasive woody plants such as Japanese knotweed, multiflora rose, Japanese honeysuckle, common yarrow, and cranesbill.

One option is to dig or pull, which is particularly effective for young weeds and woody weeds that do not produce spreading, “regrowing” basal shoots or that do not grow back easily from severed roots. Examples include honeysuckles, autumn olives, barberries, and privets.

Spot-spraying herbicides is an effective option for those who can’t or don’t want to yank. Most nonselective herbicides (i.e. those that kill almost everything green) are good at killing roots and everything, although some of the more difficult ones may require two or more applications. Just be careful not to get the spray on nearby desirable plants.

For “weeds” such as flowering pear or crabapple, a combination of pruning and herbicides is usually necessary.

Former Penn State Extension professor David Jackson suggests a blend of glyphosate and triclopyrrine as a spray that can kill most species in dense thickets of invasive insects or those that sprout new shoots and are among the most difficult to eliminate.

Jackson has produced a helpful video for Penn State that discusses the hack-and-squirt method and other ways to deal with woody weeds.

It’s worth getting to know at least the worst invaders, because it will allow you to focus your limited time and resources in a way that will yield the greatest results.

One good source for ID is the Pennsylvania iMap Invasives website, which has an “Invasive Plant Gallery.” The gallery lists about 50 of the most troublesome invasive plants in the state along with photos, videos, identification information, and facts about where each one tends to grow.

Three other good sites dedicated to marijuana identification are run by Rutgers University, Cornell University, and the University of Wisconsin.

If you’re a fan of old-school books, one of the best guides to ID is the recently updated, second edition “Weeds of the Northeast” by Joseph C. Neal, Richard H. Uva, Joseph M. DiTomaso, and Antonio DiTommaso (Comstock Publishing, 2023, $32.95 paperback).

• Read more about how to beat weeds

The Bird Benefits of Doing Nothing

Gardeners often have a lot of things to do, but sometimes doing nothing can be more beneficial than doing something.

Such is the case with the current trend among gardeners who are trying to make their gardens more bird-friendly.

The National Garden Bureau offers five ideas for doing nothing for those who have such a goal in mind.

1.) Limit or avoid pesticidesIn addition to potentially poisoning birds through direct contact, pesticides can also harm birds that feed on treated pests.

“These chemicals not only kill insects and rodents, but they can also poison birds that eat the prey,” NGB says. “Rat poison kills predatory birds like Swainson’s hawk, owls and eagles. Songbirds often mistake pesticide pellets for seeds.”

Depending on the level of toxicity, pesticides can kill birds or cause sublethal effects such as thinning eggshells, weakening the immune system and deforming embryos, which can lead to bird population declines.

2.) Leave the leaves. In addition to discouraging weeds and nourishing the soil, leaves create valuable habitat for invertebrates that birds eat—especially the favorite food source of young birds, moth caterpillar pupae. Raking or blowing every last leaf out of your yard removes this free resource from nature.

3.) Leave the seeds. Wintering birds depend on seed heads for their winter food source. Consider postponing “fall cleaning” until spring.

“Instead of removing spent flowers from annuals and perennials in the fall, do nothing,” says NGB. “Leave the seed heads on the plants as natural bird feeders. Smaller species, such as goldfinches, cling to the plants to pick seeds, while larger, ground-feeding birds forage for fallen seeds in garden beds.”

The empty stems of perennial plants also provide shelter for insects that can overwinter in them.

4.) Appreciate dead trees. Unless the dead tree poses a hazard to people or structures if it were to fall, consider leaving it standing.

“More than 80 species of birds rely on dead trees—known as “snags”—for nesting, food storage, hunting, roosting, and resting,” NGB says. “Standing tree trunks provide homes for many cavity-nesting species. Woodpeckers often create or enlarge cavities in dead trees, but many bird species will nest in them, including chickadees, great tits, treecreepers, sialikits, tree swallows, great crested flycatchers, tree ducks, and American kestrels.”

5.) Don’t throw away your brushInstead of clearing away fallen branches, shrubbery, and other woody garden waste, simply pile it up and walk away.

“The pile of branches provides shelter for the birds, protecting them from bad weather and predators,” NGB says.

• Read George’s column on 10 Ways to Attract Birds to Your Garden
• More tips on when and what to do: George’s “Pennsylvania Monthly Gardening” book