The Essential Role of Bugs in Your Garden’s Ecosystem
In the 90s, I was not thinking about including plants in clients’ yards that would attract beneficial bugs that aid in garden health. Now, I only consider, recommend, and bring in plants that play an important role in the ecosystem of the garden and beyond. Whether that’s providing nectar and pollen for those who depend on it, hosting plants for young caterpillars to feed on, or growing in a way that provides cover for prey and a place to raise their young. If you’re curious about how to bring more bugs into your garden and just how important their role in your garden is, let’s dig in.
The Role of Bugs in the Ecosystem
When I say “bugs,” I’m referring to a general class of invertebrates – those without backbones – and spiders/arachnids. These invertebrates play a key role in healthy waterways – rivers and streams – as fish and other animals feed on the bugs that live in that ecosystem. You can also thank these invertebrates for a variety of daily comforts like natural fabrics, leather, timber, and hemp.
These bugs assist with growing the cotton and linen (flax) for fabrics for our clothing, towels, and curtains. It’s also the bugs that help grow the grasslands for sheep – so they can grow their fine woolly coats for us to cut and spin – and cows – so their hide can make leather for shoes, bags, and upholstery. Not to mention the other gifts these grazers provide in the form of milk, cheese, and meat for those who indulge.
The same goes for the wooden chairs, tables, or bookcases in our homes, as well as the wood building materials used to build them. Without the important bugs and other microbiology in the soil to maintain soil health, trees wouldn’t flourish, and there would be little timber to produce furniture, paper, or even hemp for cordage, ropes, and clothing. The role of bugs in our lives is quite essential.
Plus, they contribute to a balanced ecosystem in other ways:
Become food for wildlife like birds, lizards, snakes, fish, and skunks
Act as recyclers and decomposers
Help manage pests
Work to maintain soil health
Offer pollinating services
Why Bugs Are Good For Your Garden and Beyond
Bugs play a very important role in your garden’s food web.
Everything is connected. Each column requires food from something in the previous columns.
Food webs describe the transfer of energy between species within an ecosystem. Your garden’s ecosystem is the complex living food web that surrounds you – the beneficial predators, parasitoids, pollinators, birds, bees, and beyond. Without one, the others suffer.
For example, butterflies and moths need nectar and pollen plants to feed on, to refuel, and be the host plants for their young/the larval caterpillar stage. Song birds need to feed their young thousands of caterpillars. Without this vital food source, the birds suffer greatly. Beetles – like the ladybug beetle, soldier beetle, and ground beetle – visit flowers, feeding on pollen and nectar. They also lay eggs on plants and organic matter, while some larvae overwinter in the soil, ground, or leaf litter. The adults and larval form/grubs can be food for other insects, birds, lizards, and skunks.
Many flies are nectar and pollen feeders also. Plus, the larvae and adults can be predators of other insects. Syrphid flies or flower fly larvae feed on aphids and other small garden insects. Parasitoid wasps lay eggs in or on their host. Eggs hatch and the larvae feed on the host. The adults of both need pollen and nectar. They overwinter in hosts, leaf litter, decaying stems, and organic matter. Bees – social and solitary – nest in the ground, in stems, in tunnels, and require pollen and nectar. 70% of native bees are ground-dwellers and the other 30% nest in stems of plants, cavities, or tunnels in wood.
The interconnectedness of these organisms is what you want to nurture. The more you support this system, the healthier your soil, garden, and ecosystem will be. But what happens when you don’t? Insect populations decline.
Causes For Decline
There has been a steep decline in bugs – 41% over the past 10 years and 75% over the past 30 years. The main causes for decline include:
Industrial farming of crops and livestock
Mining
Urban development
Air, soil, and water pollution from synthetic pesticides and fertilizer use
Light and noise pollution
Biological factors like the introduction of diseases or species that can predate/outcompete native varieties
Climate change, changing weather patterns, and early or late blooming of plant species that are out of sync with the pollinator that relies on them
Now that you know the essential role that bugs play in your garden and the ecosystem beyond it, why would you ever consider killing them? You might even want to start gardening for these good bugs. If so, here’s how.
How to Bring Bugs into Your Garden
1. Provide a Compatible Habitat
To attract beneficial insects, bees, butterflies, birds, and beyond, your garden must have the resources they need to feel welcome. This includes food, nesting, shelter, and water.
Flower seeds, petals, fruits, leaves, anthers, stamen, roots, organic matter, decaying matter, pollen, nectar, and stems are all important as well. Just keep in mind that the needs of insects often change throughout their different life stages.
2. Plant More Perennials
Perennial plants are low-maintenance, sustainable, and help support wildlife as well as beneficial insects. They grow deep roots that nourish the soil in your garden, and the flowers that bloom provide pollen and nectar for the bugs to feed on.
3. Favor Native Species
A ratio of 70%-80% native plants is ideal for your garden if you want to bring in the beneficial bugs. Must-have California-native plants include:
California buckwheat - Eriogonum species
Sunflowers - Helianthus species
California lilac - Ceanothus species
Yarrow - Achillea millefolium
Manzanita - Arctostaphylos species
Foothills penstemon - Penstemon heterophyllus
Coat live oak
270 species of butterflies and moths can lay eggs on this plant
Sage - Salvia species
California poppies and phacelia
Easily grown from seeds distributed during the rainy season
4. Include a Wide Diversity of Flowering Plants
In addition to native plants, non-native plants like scabiosa, coreopsis, nepeta, and asters are important to have in your garden. Many of the beneficial predators and parasitoids are tiny – I call them micro-pollinators – so they need tiny flowers to collect pollen and nectar to feed on.
This includes yarrow, ceanothus, California-native buckwheat, parsley, cilantro, and dill, as well as composite flowers like asters, sunflowers, erigeron, and gaillardia. It also includes small tubular flowers like agastache, sages/salvias, phacelia, and basil, in addition to larger tubular flowers like larger salvias, penstemon, and bee balm.
5. Companion Plant and Interplant Food Crops With Flowering Plants
Diverse plant choices are incredibly beneficial to the health of your garden. Some plants provide pollen and nectar while others serve as shelter. This attracts the insects that can keep the pests you don’t want around out of the ecosystem. Plus, more biodiversity supports a healthy garden!
6. Leave the Leaves
If you rake up the leaves from your yard or garden, you reduce the butterfly and moth emergence by 45%, spiders by about 55%, and beetles by about 25%. These are all incredibly beneficial bugs to lose! Plus, why clean up when it’s a good thing to allow your plants to complete their life cycle?
Birds eat seeds and berries, while many tiny pollinators like parasitic wasps prefer the tiny flowers from many of the culinary herbs that go to flower. You’re not a lazy gardener to leave the leaves or let your plants complete their life cycle.
If you must cut your perennials back, leave the stems between 8-20 inches for native bees who create nests in the pithy centers of the stems. If you cut the stems to the ground, then leave the cuttings in bundles. You can also line walkways or garden beds with cut branches or logs from pruned trees. Beetles and native bees will nest in those areas. You might also see fence lizards, salamanders, and garden snakes.
Ways to Grow Together
You may be familiar with the rewilding movement. Well, I’d like to start the rebugging movement! This involves bringing more awareness to the importance of attracting bugs to and supporting life in our gardens. Everything is connected. The small shifts we make in our actions and the changes we make in our gardens have a big impact on the ecosystem and beyond.
Let’s learn to live with nature, to love the bugs, to get curious and excited when we see them in our gardens.