Kitchen Science #5: Garden Science, 3 Brilliant Experiments to Explore Ecology in Your Own Back Garden

 

Kitchen Science #5:

Garden Science, 3 Brilliant Experiments to Explore Ecology in Your Own Back Garden

May is arguably Britain's finest month in the garden. Everything is growing at full throttle—leaves fully unfurled, insects humming, birds nesting, soil teeming with life. If January offered us the crystalline perfection of frozen water and April gave us the drama of weather systems, May delivers something richer and more complex: ecology in action. Every square metre of your garden harbours interactions of breathtaking intricacy—plants competing and cooperating, insects pollinating and predating, soil organisms recycling and transforming, all woven into a web of relationships that has taken millions of years to develop.

This month's experiments take you deep into that web. You'll investigate how plants compete for resources, discover the extraordinary biodiversity hiding in your soil, and learn to observe pollination with new eyes. None of these experiments require specialist equipment—your garden itself is the laboratory, and curiosity is the only tool you truly need. These are experiments best done with other people nearby: share what you find with whoever's curious enough to look. You might be surprised how much wonder is hiding in plain sight.

Experiment 1: The Great Soil Safari

What You'll Learn

Discover the astonishing biodiversity in a single spade-full of your garden soil, learning how soil food webs work and why healthy soil is the foundation of all land-based ecosystems. This experiment reveals a hidden world more biologically diverse than any rainforest canopy.

Equipment Needed

• A garden spade or trowel
• A large white sheet, plastic sheet, or several sheets of white paper
• A magnifying glass (10x magnification ideal)
• Tweezers or two small sticks for moving specimens
• A notebook and pen for recording
• Several clean, clear glass jars with lids (for temporary observation)
• A ruler
• A camera or phone for photographs
• Optional: A jeweller's loupe or hand microscope for closer examination

Estimated cost: £0-5 (if you need to purchase a magnifying glass)

Where to source: Magnifying glasses are available in pound shops, garden centres, or online. Hand microscopes cost £8-15 online and open up an extraordinary world of observation.

Safety note: Wash hands thoroughly after handling soil. Wear gardening gloves if preferred. Be cautious returning all creatures to their habitat after observation.

Method

1. Choose your site (5 minutes) Select several different soil sites to compare: a well-established garden bed, a lawn area, a recently disturbed or bare patch, and if possible, a spot under leaf litter or compost. Different habitats within your garden will yield very different communities, and comparing them reveals how ecology responds to conditions.

Mark your sites so you can return to the same spot. Make notes about each site: Is it sunny or shaded? Wet or dry? Recently dug or undisturbed? What plants are growing nearby?

2. Extract your samples (10 minutes) From each site, carefully remove a block of soil about 20cm × 20cm × 20cm—approximately one spade depth. Place it gently on your white sheet or paper. White background makes it far easier to spot creatures, especially small ones.

Work through the soil block slowly, breaking it apart by hand (or with sticks) into smaller sections. Move carefully and avoid crushing.

3. Survey and record (30-60 minutes, take your time) Begin counting and identifying everything you find. Record in your notebook:

• Every earthworm (count carefully—they may surprise you)
• Every insect larva (note colour, size, number of legs)
• Every beetle or beetle larva
• Centipedes and millipedes (count their legs to tell them apart—centipedes have one pair per body segment, millipedes have two)
• Spiders and mites
• Snails and slugs
• Any plant roots and their condition
• Anything you can't identify (photograph it for later research)

Use tweezers or sticks to gently move creatures for closer examination. Place anything interesting temporarily in a clear glass jar for magnified observation, then return it to the soil.

4. Examine microscopically (15 minutes) If you have a hand microscope, place a small pinch of soil on a white surface and examine it. You should see:

• Tiny white or pale mites (often abundant)
• Springtails (minute insects that jump when disturbed)
• Fungal threads (white strands connecting soil particles)
• Nematodes (thread-like worms) if you're very lucky

5. Compare your sites (ongoing) Repeat the survey at your different sites and compare numbers and diversity. A healthy established garden bed should dramatically outperform recently disturbed soil, illustrating how ecological communities take time to develop.

Return all organisms to their original holes. Backfill the soil.

Expected Results

Most gardeners are genuinely astonished by what they find. A single 20cm cube of healthy garden soil can contain:

• 100-500 earthworms per square metre (so 25-125 in your sample)
• Dozens of beetle larvae and adult beetles
• Centipedes and millipedes in abundance
• Multiple spider species
• Thousands of mites (visible under magnification)
• Tens of thousands of springtails (visible under magnification)
• Hundreds of millions of bacteria (invisible without microscopy)
• Kilometres of fungal threads

You'll likely find that your well-established garden bed vastly outperforms recently dug or disturbed areas. This illustrates ecological succession—communities rebuild complexity after disturbance, but this takes time. Soil compaction, chemical treatments, and repeated disturbance all reduce biodiversity.

Troubleshooting: If you find almost nothing, your soil may be very acidic, waterlogged, recently treated with pesticides, or heavily compacted. Very sandy soils hold fewer organisms than clay or loam. Try a different area. If you find earthworms only near the surface, the deeper soil may be too dry—earthworms retreat deep in dry conditions.

The Science Explained

Soil isn't just dirt—it's Earth's most biodiverse habitat and the foundation of virtually all terrestrial life. A single teaspoon of healthy garden soil contains more microorganisms than there are humans on Earth.

The soil food web is structured in trophic levels. At the base, producers (plant roots and algae) provide energy through photosynthesis. Primary consumers eat these producers—nematodes graze on bacteria and fungi, earthworms ingest organic matter, springtails eat fungal hyphae. Secondary consumers eat the primary consumers—predatory mites eat nematodes and springtails, centipedes eat various invertebrates. Tertiary consumers sit at the top—predatory beetles and ground beetles eat invertebrates.

Earthworms are ecosystem engineers. They ingest soil, extract nutrients, and excrete worm castings that are dramatically richer in plant-available nutrients than the surrounding soil. They create channels that improve drainage and aeration. Charles Darwin's last major scientific work was a detailed study of earthworm ecology; he calculated that British earthworms turn over the entire top layer of soil every few decades. Every plant growing in your garden depends on this service.

Fungi are perhaps the most important but least visible component. Fungal threads (hyphae) extend throughout healthy soil, breaking down organic matter, transporting nutrients, and connecting plant roots in the mycorrhizal network—the "wood wide web" through which plants share nutrients and even communicate. Most garden plants form these fungal partnerships; disrupting soil destroys these networks, which is one reason repeatedly dug soil loses productivity.

Decomposers—bacteria, fungi, and many invertebrates—are the recycling system underpinning everything. They break down dead organic matter, releasing nutrients that plants can absorb. Without decomposers, nutrients would be locked in dead material indefinitely, and plant growth would cease.

The diversity you find in your soil directly correlates with your garden's health. More species means more ecological functions, more resilience, and better support for the plants above ground.

Real-World Applications

Soil ecology underpins global food security. Agricultural soils worldwide are being degraded through intensive cultivation, chemical use, and monoculture, reducing the biological communities that maintain fertility. Regenerative agriculture—farming practices that rebuild soil communities—is increasingly recognised as essential for sustainable food production.

Soil organisms are bioprospecting targets for medicine. Streptomycin, one of the first antibiotics effective against tuberculosis, was discovered in soil bacteria. Soil fungi produce numerous compounds with medical potential. The next antibiotic breakthrough might be hiding in your garden bed.

Climate science increasingly recognises soil as a crucial carbon store. Healthy soils contain enormous quantities of carbon locked in organic matter and organisms. Degraded soils release this carbon as CO₂. Rebuilding soil health could sequester significant amounts of atmospheric carbon.

Taking It Further

Variation 1: Set up a simple experiment comparing soil from organic, mulched beds versus regularly dug, chemically fertilised beds. Count organism numbers and diversity in each. The difference can be dramatic.

Variation 2: Create a pitfall trap—bury a jar flush with the soil surface, baited with a small piece of fruit. Leave for 24-48 hours and see what crawls in. This samples surface-dwelling organisms different from your spade survey.

Variation 3: Try the Berlese funnel technique. Fill a funnel with soil, place a light bulb above it, and put a jar beneath. Organisms flee the heat and light downward, dropping into the jar. This is how professional ecologists collect soil invertebrates.

Related Questions to Explore:

• How do earthworms breathe through their skin, and what does this mean for their sensitivity to chemicals?
• What's the difference between centipedes (carnivores) and millipedes (detritivores)?
• Why does disturbing soil reduce its carbon content?

Experiment 2: Build an Insect Hotel and Count Your Guests

What You'll Learn

Create habitat for solitary bees and other beneficial insects, then observe and record who moves in—discovering the relationship between habitat, species diversity, and ecological services like pollination. This experiment transforms garden observation into active ecology.

Equipment Needed

For the insect hotel:

• A wooden crate, box, or large plastic bottle (for the frame)
• Bamboo canes, cut into 15cm lengths
• Hollow plant stems (elder, buddleia, or similar)
• A bundle of thin sticks and twigs
• Pinecones
• Dry leaves
• Cardboard rolled into tubes
• Optional: A drill and wooden blocks to create drilled holes (5-10mm diameter)
• Waterproof backing material (a piece of slate, tile, or sealed plywood)

For observation:

• A notebook and pen
• A magnifying glass
• A camera or phone

Estimated cost: £0-10 (most materials from garden waste)

Where to source: Bamboo canes from garden centres or cut from your garden. Hardware stores sell drill bits for wooden blocks.

Safety note: When cutting bamboo, ensure cuts are clean and smooth to avoid sharp edges that could injure insects. Adult supervision for drilling.

Best time to deploy: Early May gives solitary bees time to find and use the hotel throughout the season.

Method

1. Build your hotel (30-45 minutes) Fill your container with a variety of materials, each providing different cavity sizes for different insect species:

• Large tubes (8-10mm diameter): For larger solitary bees like leaf-cutter bees and mason bees. Use bamboo, rolled cardboard, or drilled wooden blocks.
• Medium tubes (5-7mm diameter): For smaller solitary bees and some wasps. Hollow plant stems work well.
• Small tubes (3-5mm diameter): For small mason bees and solitary wasps.
• Gaps and crevices: Fill sections with bundles of thin twigs, rolled dry leaves, pinecones, and bark—housing lacewings, ladybirds, earwigs, and beetles.

Pack materials tightly enough that they don't fall out but not so tightly that insects can't enter. The tubes should be smooth inside—rough tubes discourage use.

Ensure your hotel has a waterproof back and overhang to keep nesting materials dry. Moisture will rot materials and kill eggs and larvae.

2. Position your hotel (10 minutes) Placement is crucial. Solitary bees are sun-seekers—position your hotel facing southeast to south, with the tubes roughly horizontal, at a height of 1-1.5 metres. Keep it still once positioned; moving an active hotel destroys nests.

Ensure the hotel is near bee-friendly flowers. Solitary bees don't travel far from nesting sites—they need food sources within a few hundred metres.

3. Begin monitoring (5-10 minutes daily) Start a systematic monitoring log from day one:

• Date and time of observation
• Temperature and weather conditions
• Which tubes/sections are showing activity
• Behaviour observed (bees entering carrying pollen, exiting, hovering to orientate)
• Evidence of use (tubes sealed with mud, leaves, plant material)

Tube sealing indicates successful nesting. Different species seal tubes differently:

• Red mason bees seal with mud
• Leaf-cutter bees seal with cut leaf pieces
• Other bees may use plant material, resin, or other materials

4. Continue observation throughout the season (Weekly until autumn) Mark sealed tubes with small sticky dots so you don't confuse them with unsealed ones. Count sealed tubes weekly. By late summer, you should have a clear picture of usage.

Don't open sealed tubes—they contain developing larvae that will emerge the following spring.

Expected Results

Within 1-4 weeks of installation in a well-positioned hotel, you should see insects investigating tubes. Red mason bees (a common early-season species) are often the first to move in, followed by leaf-cutter bees in June and July.

A well-positioned hotel in a bee-friendly garden might see 50-100% of suitable tubes occupied by season's end. You may observe:

• Bees hovering in figure-of-eight patterns near the hotel, learning its location
• Bees carrying pollen balls into tubes (provisioning the nest with food for larvae)
• Bees sealing completed cells with mud or leaves
• Parasitic wasps attempting to lay eggs in occupied tubes

The diversity of tenants reflects your garden's ecology. Multiple bee species indicate diverse flower resources. Parasitoid wasps indicate healthy population densities of their hosts. Lacewings and earwigs in the crevice sections provide natural pest control.

The Science Explained

Most people think of bees as social insects living in hives—but of the roughly 270 British bee species, fewer than 30 are social. The rest are solitary bees: each female mates, finds a nesting site, provisions individual cells with pollen and nectar, lays eggs, and seals the cells without any colony support. She typically dies before her offspring emerge.

Solitary bees are vital pollinators—in many cases more efficient than honeybees because they're not collecting pollen to feed a large colony but simply enough for their own offspring. Red mason bees, for instance, are 120 times more efficient at apple pollination than honeybees, because they're messier—they don't compact pollen tightly but carry it loosely, dropping more on flowers.

Your insect hotel demonstrates resource limitation—a fundamental ecological concept. Solitary bee populations are often limited by nesting site availability rather than food. Building a hotel directly increases carrying capacity (the maximum population an environment can support), potentially boosting local pollinator populations.

The niche concept is visible in tube diameter preferences. Each bee species is specialised for particular tube diameters—too small and they can't enter, too large and they can't create a snug cell. By providing multiple diameter options, you create multiple niches, supporting multiple species.

Ecological services from your hotel residents are real and significant. Solitary bees pollinating your garden and neighbouring gardens directly increase fruit and seed set. Lacewings eat aphids—one lacewing larva can consume 200 aphids before pupating. Earwigs, despite their fierce reputation, eat aphid eggs and other pests.

Real-World Applications

Global pollinator decline is a genuine crisis. Honeybee populations are falling due to habitat loss, pesticide use, and the Varroa mite. Wild bee populations have declined by up to 30% in some regions. This threatens food security—roughly one-third of human food depends on animal pollination.

Insect hotel programmes in cities, farms, and gardens worldwide are part of the response. Urban ecology research shows that diverse urban habitats can support surprisingly robust pollinator populations. Cities with extensive insect hotel programmes report increased fruit set in urban orchards and allotments.

Agricultural research is using insect hotel designs to boost farm pollinator populations, potentially reducing reliance on costly, managed honeybee colonies. The ecological principle—habitat determines population—drives these practical applications.

Taking It Further

Variation 1: Build two identical hotels, position one in full sun and one in partial shade, and compare occupancy rates. This demonstrates how temperature preferences shape habitat selection.

Variation 2: Create a "before and after" measure by tracking flowers in your garden before installing the hotel and measuring fruit/seed set. Compare to a section of garden without nearby hotels to see pollination effects.

Variation 3: Photograph your hotel residents and use identification guides (or the iRecord or iNaturalist apps) to identify species. Britain has a remarkable diversity of solitary bee species, each with distinct habits.

Related Questions to Explore:

• How do leaf-cutter bees cut such perfect circles from leaves?
• Why do mason bees use mud rather than other materials?
• What is the relationship between bee tongue length and flower shape?

Experiment 3: Observe a Pollination Network

What You'll Learn

Map the connections between insect visitors and flowers in your garden, discovering how pollination networks are structured, what determines which insects visit which flowers, and why diverse gardens support more robust ecological communities.

Equipment Needed

• A notebook dedicated to this experiment
• Pen or pencil
• A watch or timer
• Identification guides for bees, hoverflies, and common garden flowers (or the iRecord/iNaturalist apps on your phone)
• A magnifying glass
• Optional: A camera for documentation

Estimated cost: £0 (plus app downloads if using identification apps—both free)

Where to source: iNaturalist and iRecord are free apps with identification help from both AI and community members.

Best time: May-August, warm sunny days between 10am-4pm when insect activity peaks.

Method

1. Select your observation patch (5 minutes) Choose an area of your garden with several different flowering plants. The ideal observation patch is small enough to watch all at once but diverse enough to include 4-6 different flower species. A typical mixed border, a patch of wildflowers, or a kitchen garden works perfectly.

2. Create your observation record format (5 minutes) Rule columns in your notebook with the headings:

• Time
• Flower species visited
• Insect species/type (bee, bumblebee species, hoverfly, butterfly, moth, etc.)
• Behaviour (collecting pollen, drinking nectar, or both)
• Duration on flower (seconds)

If you can't identify insects precisely, use broad categories: "large bumblebee," "small dark bee," "striped hoverfly," etc. Even broad categories reveal patterns.

3. Conduct timed observation sessions (20-30 minutes per session) Sit quietly (insects acclimate to human presence quickly) and record every insect visitor to every flower in your patch during the observation period. Note all details in your observation format.

Conduct at least 3-4 sessions on different days and at different times within the recommended window. Different species are active at different times; some flowers receive peak visits in the morning, others in the afternoon.

4. Build your network map (10-15 minutes per session) After each session, create a visual network map:

• List flowers along one edge of a page
• List insect types along the other edge
• Draw lines connecting each insect to each flower it visited
• Make lines thicker for more frequent interactions

After several sessions, you'll have a visual representation of your garden's pollination network.

5. Analyse your network (15 minutes) Look for patterns:

• Which flower receives the most diverse insect visitors?
• Which insect visits the most flower species?
• Are there specialist relationships (one insect only visiting one flower type)?
• How does activity change with time of day and temperature?

Expected Results

You'll likely discover that your garden's pollination network has a characteristic structure. A few highly connected "hub" species—both flowers that attract many insect types and insects that visit many flower types—link together with many more specialised interactions.

Common patterns include:

• Bumblebees visiting a wide range of flowers but preferring tubular shapes
• Short-tongued bees restricted to open, accessible flowers
• Hoverflies preferring flat, open flowers (umbellifers, daisies)
• Butterflies favouring nectar-rich flat or tube flowers in purple/pink/yellow colours
• Specialist bees (like hairy-footed flower bees) visiting only specific flower genera

You should also observe temporal partitioning—different species visiting the same flower at different times of day, reducing competition. Early morning might bring bumblebees; midday, hoverflies; late afternoon, mining bees.

The Science Explained

Pollination networks reveal fundamental ecological principles about coevolution—how plants and their pollinators have shaped each other's evolution over millions of years.

Flower shapes, colours, and scents are adaptations for attracting specific pollinators. The fit between flower and pollinator is often exquisitely precise: Foxgloves have tubular flowers with patterns on their interior lips that guide bumblebees (which are long-tongued and robust enough to enter) to pollen and nectar. Flat umbellifer flowers (like fennel and cow parsley) are easily accessible to short-tongued insects like hoverflies and small bees. Night-scented flowers like evening primrose attract moths.

Tongue length is particularly important. Long-tongued bees like garden bumblebees can access deep flowers that short-tongued species cannot. This creates functional ecological niches—different bee species can access different floral resources, reducing direct competition.

Your network map illustrates keystone species—organisms whose removal would significantly disrupt the network. If one insect species visits many flowers, its decline would affect many plant species' reproduction. If one flower attracts many insects, its removal reduces resources for the entire community.

Pollination syndrome—the set of floral traits associated with particular pollinator groups—explains many observations you'll make. Yellow and white flowers are often visited by bees and butterflies; red flowers are less visible to bees (which can't see red well) but attractive to butterflies. Strongly scented flowers with hidden nectar often attract moths and some specialist bees. Understanding these syndromes lets you predict which insects you'll find before you begin observing.

Real-World Applications

Pollination network research informs conservation and agriculture. Ecologists studying real-world networks have found that biodiversity increases network robustness—diverse communities with many species and interactions are more resilient to the loss of individual species than simple communities with few connections.

This has practical implications for farming. Monoculture landscapes with few plant species support simplified, fragile pollination networks. Diversified farming landscapes with hedgerows, wildflower margins, and varied crops support complex, robust networks with better pollination services.

Garden design informed by pollination network research—providing diverse flower species with staggered blooming times, including specialist plants for specialist insects, avoiding pesticides that harm pollinators—can create gardens that function as genuine ecological habitats rather than merely decorative spaces.

Citizen science projects like the UK Pollinator Monitoring Scheme ask exactly what you're doing in this experiment: systematic observation of insect-flower interactions. Your observations, if submitted to such schemes, contribute to national-scale understanding of pollinator diversity and activity.

Taking It Further

Variation 1: Compare observation sessions in warm versus cool weather. Insect activity dramatically reduces below about 12°C. Plot your visit rates against temperature to see the relationship.

Variation 2: Add a new flowering plant species chosen for its specialist visitors (try viper's bugloss for solitary bees, or fennel for hoverflies) and monitor whether new insect species appear in your garden.

Variation 3: Survey during different months to see how the network changes seasonally. Spring networks are typically dominated by early bumblebees; summer networks expand to include dozens of solitary bee species; autumn networks shift to flowers like ivy and Michaelmas daisy.

Related Questions to Explore:

• How do bees communicate the location and quality of flower patches to nest mates?
• Why do flowers produce nectar "guides"—patterns visible in ultraviolet light that bees can see but humans cannot?
• How might changes in flowering plant communities affect the diversity of specialist bee species?

Connecting May's Ecology Experiments

These three experiments explore ecology at different scales—from the microscopic world beneath your feet to the intimate interactions between insect and flower. Yet they're deeply connected.

The soil food web (Experiment 1) supports plant health through nutrient cycling and root partnerships, which determines what plants can thrive in your garden. Healthy, thriving plants produce more abundant flowers, which support the pollination network (Experiment 3). Abundant flowers near suitable nesting habitat attract solitary bees (Experiment 2), whose nesting success depends partly on provisioning enough pollen—which depends on a rich pollination network. And when those solitary bees die, their bodies return to the soil food web, completing the cycle.

This interconnection is ecology's central insight: living systems aren't collections of independent organisms but webs of relationships, where each connection depends on and maintains others. Your garden isn't a collection of plants and animals but an ecosystem—a functional community where species interact in ways that collectively maintain conditions for all.

Understanding this web changes how you think about garden management. Every decision—what to plant, when to dig, whether to use chemicals, how to manage pests—affects multiple nodes in the network. The gardener who understands ecology makes different choices than one who sees the garden as a collection of individual plants to be managed separately.

May is the perfect month to begin developing that ecological perspective. The whole system is fully active, visible, and accessible. Pull on your gloves, sit quietly in the sunshine, and let your garden show you what it knows.

Ecology is the science of relationships—how organisms interact with each other and with their environment. Your garden in May is a masterclass in this science, a spontaneous university offering lectures in competition, mutualism, parasitism, predation, and decomposition simultaneously. No textbook can compete with the real thing. The earthworm in your hand, the bee hovering at your lavender, the invisible fungal threads binding your soil together—these are ecology made tangible, science you can touch. And the more carefully you observe, the more clearly you'll see that your small patch of Britain is not separate from nature but entirely part of it, governed by the same ecological laws that govern forests and oceans, just playing out at garden scale.