Rot or Not? — The Buried Rubbish Dig

The child buries a few everyday items in soil, predicts which ones nature will “eat”, and digs them up weeks later to find out — a first lesson in materials, decay, and why litter matters.

  1. Gather 5–6 small items made of different materials — for example an apple core or banana peel, a lettuce leaf, a piece of paper or cardboard, a plastic bottle cap or wrapper, a scrap of foil, and a small stone.
  2. Lay them out and ask about each one, “Where did this come from — a plant, or a factory?” Then, “If we bury it, do you think it will still be there in a month?” Draw each item and mark the child’s prediction with a tick or cross.
  3. Bury the items a hand’s depth down in a garden bed or a large pot of ordinary soil, each next to a labeled lolly stick so you can find it again. Water lightly.
  4. Keep the soil slightly damp. Mark the calendar for a “dig day” three to four weeks later.
  5. On dig day, the child excavates each item with a spoon, wearing gloves. Compare what you find with the drawings — “What happened to the apple? What about the plastic?”
  6. Talk about what it means: things that came from plants and animals rot away and turn back into soil; plastic, metal, and glass do not, so they must go in the bin or be recycled, never left on the ground.

Variation: on a walk, play “Would it rot?” with things you spot — a fallen leaf, a drinks can, a twig, a crisp packet — and pick up one piece of litter (with a bag over the hand) to bin on the way home.

Requirements

  • Space: A corner of a garden bed, or a large plant pot or bucket of soil on a balcony
  • Surface: Outdoor soil; newspaper under the pot on dig day
  • Materials: 5–6 small items of different materials, soil, lolly sticks or twigs as markers, an old spoon, gloves, paper and crayon
  • Participants: 1 adult + 1 child
  • Supervision: Moderate on burying and dig days; a minute now and then to water in between

Rationale & Objective

Caring for the natural world starts with understanding what happens to the things we throw away. Hirsch’s kindergarten science includes taking care of the earth (conservation, recycling, litter), and NGSS K-ESS3-3 asks children to communicate ways of reducing human impact on land, water, air, and living things. Research on children’s ideas about the cycling of matter (Leach, Driver, Scott & Wood-Robinson, 1996) found that the youngest children could rarely explain decay — many expected a fallen apple to stay much as it was, and only a few thought it would rot away or turn into soil. This slow experiment gives a direct, memorable observation to build on: natural materials change and vanish into the soil, while manufactured ones stay exactly as they were. It also introduces sorting materials by origin and property (EYFS; GOLD Objective 26) and gives a concrete reason for the binning and recycling habits children are asked to follow. Waiting several weeks for a result is itself good practice in patience and in keeping a prediction in mind.

Progress Indicators

  • Early: predicts by size or by liking (“the stone is too hard”, “I like apples so it stays”); is surprised that anything changed; says the apple “went away”
  • Developing: predicts correctly for the most obvious items (food versus stone); describes what was found (“mushy”, “all gone”, “same”); names what some items are made of
  • Proficient: sorts items into “rots” and “doesn’t rot” and explains that things from plants go back into the soil; says why plastic should not be dropped outdoors
  • Advanced: predicts for new items by thinking about material (“a wooden stick will rot, but slowly”); connects the dig to compost and recycling at home; wonders what does the rotting (worms, tiny living things)

Safety Notes

  • Wear gloves for the dig and wash hands thoroughly afterward; cover any cuts on hands before handling soil
  • Do not bury meat, fish, dairy, or cooked food — they smell and attract rats and other pests
  • Decaying food may be mouldy; look without sniffing closely, and let an adult handle the dig if the child has asthma or a mould allergy
  • Use only blunt, safe items — no glass, tins with sharp edges, or batteries
  • Remove and correctly bin all the non-rotting items at the end, and pick up litter outdoors only with a bag or gloves, never sharp or dirty objects

Hints

  • Playfulness: bury the items like pirate treasure and draw a map with an X for each one. On dig day the child is an archaeologist with a spoon and a paintbrush
  • Sustain interest: a month is a long wait, so draw a countdown on the calendar and do one sneak-peek at the halfway point on a single item. Re-bury the leftovers and check again a month later
  • Common mistake: letting the soil dry out or burying things too deep and cold, so nothing happens. Damp soil in a warm season gives the clearest result; in winter, expect it to take twice as long
  • Limited space: use two clear jars of damp soil on a shady windowsill ledge outdoors — a lettuce leaf in one, a plastic scrap in the other, pressed against the glass so changes can be seen without digging
  • Cross-domain: predicting and checking (scientific thinking); sorting by material (classification); counting down days on a calendar (time concepts); taking a real job in the family’s recycling routine (responsibility)
  • Progression: food versus stone → add paper, plastic, and metal → predict before burying → explain the result in terms of materials → sort the household recycling → start a small compost pot for fruit and vegetable scraps

Sources

  • Leach, J., Driver, R., Scott, P. & Wood-Robinson, C. (1996), “Children’s ideas about ecology 2: ideas found in children aged 5–16 about the cycling of matter,” International Journal of Science Education
  • E.D. Hirsch — What Your Kindergartner Needs to Know (Science — taking care of the earth)
  • NGSS K-ESS3-3 — communicate solutions that will reduce the impact of humans on the land, water, air, and other living things
  • UK EYFS — Understanding the World, The Natural World ELG (important processes and changes in the natural world)
  • Teaching Strategies GOLD Objective 26 (physical properties of objects and materials) and Objective 27 (Earth’s environment)
  • US EPA — Composting at Home guidance (what to compost and what to leave out)