11 Ways You Can Help Reverse Insect Decline in Your Garden

Insects are declining at alarming rates. This may sound like a good thing (less annoying mosquitoes and hungry garden pests), but it is actually a major risk for wildlands and agricultural landscapes. We all know that pollinators like bees and butterflies are vital assets to our food supply, but billions of other insects are equally important, especially when trying to avoid pesticide use. 

Humans have identified over one million species, and only about one to three percent of insects are considered “pests” in our homes or landscapes. In other words, the “good guys” outweigh the bad. With the bulk of insects remaining beneficial, it is crucial to consider how we can help reverse their decline by making our gardens more welcoming to the wild critters that mean no harm.

Here are 11 simple ways to help reverse insect decline by creating habitat in your garden.

Are Insects Declining?

Entomologists estimate that insects have declined by 45% in the last 40 years. This mass-scale death threatens wild ecosystems and agriculture. The top reasons may sound familiar—habitat loss and climate change—but there are many underlying issues at play.

Pesticide use, overly manicured landscapes, outdoor lights, water pollution, and lack of biodiversity in urban landscapes make it difficult for beneficial insects to proliferate. 

Let’s dig deeper into these affordable and aesthetically-pleasing possibilities for making your garden helpful for both humans and insects.

11 Ways to Help Reverse Insect Decline

The doom-and-gloom of mass extinction is nothing new to anyone who cares about Mother Nature. But while polar bears and white rhinos get a lot of attention, many of us are unaware of the smaller critters rapidly disappearing.

Over 40% of insect species could go extinct in the next few decades. Studies show that Lepidoptera (butterflies and moths), Hymenoptera (bees, ants, and sawflies), and Coleoptera (beetles) are the most threatened. Fortunately, these are some of the easiest arthropods to welcome into our home landscapes. 

Grow Buffer-Season Flowers

There are lots of floral resources in the middle of summer, but early spring and late fall often have dwindling blooms. Most insects rely on nectar and pollen from flowering plants. They are especially vulnerable when they emerge from hibernation in late winter and early spring.

If we provide early-blooming flowers, it can help bees, butterflies, wasps (most are not harmful to humans), moths, and flies to survive and reproduce in the summer. 

The fall is another time where floral resources are often scarce. Many plant species go to seed, leaving few nectar or pollen resources. However, insects still need to forage on flowers to prepare for the winter. For example, native bees and honeybees must acquire enough food resources to protect their nests or hives during the winter. 

It’s helpful to keep these plants established in your garden so they can offer floral resources all season long until the first frosts.

Avoid Broad-Spectrum Pesticides

Pesticides are obviously a major threat to insects, but broad-spectrum chemicals are particularly problematic. “Broad-spectrum” means it can kill any bug that encounters the compound, including a beneficial predator that is higher in the food chain. In contrast, narrow-spectrum products specifically target a select group of pests. 

If you are struggling with crop infestations, consider organic options like neem oil, Sluggo, horticultural soap, or Bt (Bacillus thuringiensis). These sprays can directly target pests without posing harm to beneficial insects when applied appropriately. If you absolutely must use synthetic pesticides, opt for low-impact, narrow-spectrum insecticides that won’t harm bees, beetles, parasitic wasps, spiders, and other predators.

Pesticides are a major cause of insect decline, and this step alone can significantly help reverse the loss of biodiversity in your garden. Contrary to popular belief, herbicides and other synthetic chemicals are also threatening to biodiversity. While they are marketed as weed-killers, herbicides are proven to kill insects directly. For example, glyphosate (RoundUp) disrupts the guts of honey bees and makes it difficult for them to navigate. 

Whenever possible, use organic growing methods for your edibles, lawn, and ornamental beds.

Use Physical Crop Protection

Avoiding pesticides doesn’t mean you have to let infestations run rampant on your favorite plants. Instead, consider Integrated Pest Management (IPM) strategies such as physical pest exclusion. This means using row fabric or insect netting to cover your most valuable or vulnerable plants. 

For example, row cover is great for newly emerging brassica seedlings that are vulnerable to flea beetles. Turnips, radishes, arugula, and kale all appreciate the physical barrier. 

Insect nets are perfect for screened sunrooms, greenhouses, or low tunnels. You can also use shade cloth as insect netting in the Deep South when summer temperatures are very intense.

Kaolin clay and diatomaceous earth are more examples of physical barriers. These powdered natural products microscopically pierce the exoskeletons of pests like cucumber beetles or squash bugs. 

However, you want to use these sparingly, as they can still contribute to insect decline if used in excess. They are not nearly as harmful as pesticides, but you only want to apply physical deterrents on the specific plants at risk. For example, you could sprinkle kaolin clay over your cucumber plants to deter cucumber beetles but avoid spreading it on the soil surface.

Leave Wild Patches

Manicured landscapes are the hallmark of the 21st century. These “monocultures” are a major reason for insect decline, but also a major opportunity for reversing the trend. Monoculture means growing just one or a select few plant species over a large area. 

For example, a big grass lawn or a huge field of corn are considered monocultures. It is OK to maintain some manicured areas, but it also helps to leave wild patches or borders as habitat for beneficial critters.

Thankfully, wild patches do not need to be ugly or unsightly. In fact, wildflower gardens and meadows can be absolutely beautiful if planned correctly. The trends toward prairie gardens, cottage gardens, and pollinator patches are great news for insect populations. 

Turn Off Outdoor Lights

Light pollution is a major driver of insect declines and another easy opportunity to reverse the trend in our landscapes. Outdoor night lights disorient most wildlife by making them think it is daytime all the time. 

Nocturnal moths, fireflies, dung beetles, and caterpillars are the most negatively affected. These animals need darkness and starlight to follow their natural cycles of feeding and reproduction. Simply turning off your outdoor lights can help these critters revitalize their populations.

You don’t have to keep your home in total darkness; a few porch lights are still OK for safety and comfort. Opt for dimmer lights that do not extend far into your garden or yard. Dark places are important for species that need to eat, drink, and migrate under starlight.

As a bonus, this can reduce the amount of bugs that come near your home. Some species are drawn to artificial lights, which can cause them to explore nooks and crannies that may lead indoors. Reducing outdoor lighting at nighttime is a win-win: Humans have fewer bug infestations in their houses, and insects are able to follow their natural rhythms without as much disruption.

Plant Native Species

Many ornamental and edible species that are commonly grown in gardens originate in far-away places. Native plants are the ancient homes of insects that live locally to you. Co-evolution describes the intricate relationships between plants and insects over millions of years. 

Co-Evolution of Insects and Plants

For example, fig trees are exclusively pollinated by fig wasps. The fig flowers emit a unique scent to attract their pollinator pals, and the flower opening is so small that the female wasp loses her wings after entering. This forces her to lay her eggs inside the blossom and lay there to rest. When the baby wasps emerge, they carry the fig’s pollen to the next bloom and proliferate the next generation of fig trees. 

On a broader scale, the mutualistic relationship between bees and flowering plants originated over 110 million years ago. During the age of Dinosaurs, flowerless plants like coniferous trees, ginkgos, and ferns covered most of the Earth. These plants did not need insects to reproduce.

But then, blooming species took over the Earth. Fossil records show that the evolution of flowering plants (angiosperms) is directly correlated with the rise in bees. Flowers have needed bees since the beginning of their existence on our planet.

Growing Regionally-Specific Plants

What does all of this mean in your garden? Well, you can imagine that the native plant species in a given region are closely linked to their insect counterparts. The deserts of the Southwest have far different native species than the East Coast, Midwest, or the Pacific Northwest, which means they also have different bees, butterflies, moths, beetles, and other arthropods.

You can help reverse insect decline by choosing regionally-native plants that attract local arthropods. This list of wildflowers for your ecoregion is an excellent place to start. Remember that, just because a plant is native to the U.S., it doesn’t necessarily mean that it is native to your exact region.

Install a Beetle Bank

A beetle bank isn’t a place for deposits or withdrawals of money. Instead, it is a patch of grasses and untamed areas where beneficial beetles can hide out, nest, and overwinter. These refuges are important for ground-dwelling beetles that are suffering from the threat of extinction.

Lucky for you, beetle banks don’t only help beetles! They can reduce pest pressure in your garden. Many species of ground beetles are predatory, which means they regularly run out to the garden to feast on grubs, maggots, caterpillars, slugs, and ants. Ecological farmers use beetle banks as a form of biological pest control around their fields. You can do the same in your edible or ornamental garden.

Consider a Lawn Alternative

Alternative lawns are all the rage for anyone interested in eco-conservation. Instead of growing boring turfgrass, you could have microclover, creeping thyme, or low-growing wildflowers blanketing your front yard. 

When considering the shift away from turfgrass, be sure to investigate blends of native ground cover species that work in specific locations of your yard. For example, you may plant a combo of clover and dwarf mondo grass in a sunny area. The foliage can provide year-round color and the clover will offer flower resources in the spring and summer. For shady areas, you may opt for mosh or creeping thyme that can add verdant green color where turfgrass traditionally struggles.

Add a Water Feature

Bees, butterflies, beetles, moths, and their relatives require the same basic needs as us: oxygen, food, shelter, and water. While standing water is often associated with mosquitoes, aerated water features attract beneficial insects to permanently reside in your garden. 

A bird bath or shallow water dish is a cheap and easy way to start. For more elaborate water features, consider installing a pond, self-cycling fountain, or a trickling zen oasis. Water movement is the key to avoiding mosquitoes. As long as you replace the water regularly, or use a small aerating pump, you should not have to worry about attracting pesky mosquitoes.

Diversify your Plantings

Biodiversity is the key to resilience in any landscape. Global biodiversity is threatened throughout the plant and animal kingdoms. With diverse plantings, we can locally help reverse the decline of insect biodiversity. Increasing biodiversity also enhances resistance to pests and diseases.

Diversity is simply the measure of different species and varieties of living organisms. Instead of planting one type of tomato or marigold, you can plant several or even dozens of cultivars. Similarly, three types of apples or cherry trees are better than a monoculture orchard of one species. 

Diversifying your garden also means diversifying your diet. You may be surprised by the abundance of lesser-known fruits, vegetables, herbs, and flowers. When shopping for seeds, aim for the greatest blend of colors, textures, flavors, fruits, and flowers. This will offer more places for insects to hide and feast because there is a greater diversity of leaf shapes, foliage densities, plant heights, flowering times, smells, pollen types, and nectar nutrients.

Start a Compost Pile

Composting is a cheap way to improve soil health with on-site resources. Kitchen scraps, fallen leaves, grass clippings, and perennial prunings are easily transformed into a rich amendment. But there is also a lesser known benefit of composting: it helps reverse insect decline!

Many beneficial insects and microorganisms are vital to the decomposition process. For example, dung beetles help biodegrade manure from chickens, ducks, cows, and horses. Without these vital beetles, many pastures and gardens would be covered with poop, flies, and parasites. These glorified poop-decomposers are globally threatened, and maintaining a compost pile could help their revival. 

Even if you don’t add manure to your compost pile, the decomposition process is still enhancing insect diversity. The larvae of beneficial predators often begin in compost piles. As materials decompose, piles also provide a habitat for roaming beetles and bugs.