Bury a cache by digging a hole just wider than a sealed rigid container, setting the top of the container at least 45 cm below the surface, backfilling in tamped layers, replacing the sod, and carrying away all the soil the container displaced, because freshly turned earth is the clue a searcher finds first. Store only dry staples in it, since a sealed, buried, cool container is the condition in which botulinum toxin forms in moist or low-acid food.
Part of Hidden Food Caches
A buried cache is a sealed container of dry food or supplies placed in a hole and covered so that the ground above it looks undisturbed.
Burial Hides Food From Eyes, Not From Water, Rodents Or Frost
The parent article calls burial the most secure concealment method: a properly buried cache is virtually undetectable without metal detectors or excavation. It gives a minimum depth of 45 cm, with 60-90 cm ideal, saving the top 10 cm of turf as an intact piece, piling soil on a tarp, backfilling in layers tamped every 10 cm, and removing the excess soil at least 100 m away.
The other article on the subject, Emergency Caches, gives larger depths: 300-600 mm for temperate short-term, 600-900 mm for 2-10 years, and below the frost line (typically 1.2-1.8 m) in cold climates, with a gravel drainage layer under the container. The two do not agree on depth, and the difference is climate and purpose: deeper protects against frost movement and casual digging but costs much more digging and makes retrieval slower. Dry sealed food is not harmed by freezing; the frost problem is that heaving soil can shift or crack the container and leave a visible hump or hollow at the surface. Observe how deep frost penetrates where you live before you choose.
What You Need
- A sealed rigid container and liner — see Container Selection
- Dry staples only — see Waterproofing and Preservation
- A spade and a trowel, a tarp, two or more sacks for spoil
- Coarse gravel, if the soil is clay or the ground is wet
- Knowledge of the site — drainage, frost depth, roots, previous use of the land
Method: Size The Hole, Dig Clean, Backfill In Layers
Step 1: Size the hole to the container. A 5-gallon bucket is about 29 cm across and 36 cm tall, figures I am recalling and which you should measure on your own bucket. Allow a hole 45 cm across, leaving about 8 cm of space around the bucket for tamped backfill. For 45 cm of cover over the lid the hole is 36 + 45 = 81 cm deep.
Step 2: Cut and set aside the sod. Cut the top 10 cm of turf in one piece and lay it on a plastic sheet in the shade so it does not dry out. Put the rest of the soil on a tarp.
Step 3: Dig straight down. A narrow hole disturbs less surface. In wet or clay soil put 10 cm of coarse gravel in the bottom so water drains away from the container; the water-table and drainage guidance in the Emergency Caches article applies.
Step 4: Place and backfill. Set the container level. Backfill in layers about 10 cm thick, tamping each; loose fill settles and leaves a depression.
Step 5: Replace the sod and dress the surface. Match the leaf litter, grass height and moisture of the ground around it. See Natural Camouflage.
Step 6: Remove the spoil. Carry it off in sacks and scatter it thinly well away from the site, as the parent article instructs.
Step 7: Do not mark the site. No stakes, cairns or paint. Record the location in the way described in Location Selection.
Worked Example: How Much Soil Is Left Over?
Take the numbers from Step 1: hole 45 cm across and 81 cm deep, container 29 cm across and 36 cm tall.
- Hole volume: π × (0.225 m)² × 0.81 m = 3.1416 × 0.0506 × 0.81 = 0.129 m³ = 129 L.
- Container volume (outside): π × (0.145 m)² × 0.36 m = 3.1416 × 0.0210 × 0.36 = 0.0238 m³ = 24 L.
- Soil that cannot go back: roughly the container’s own volume, 24 L, plus a little more for any gravel layer.
So about 24 L of soil, close to a full bucket, has to be carried away from every hole, and loose soil takes more room than packed soil, so expect more. Piles left near the cache are what the parent article means by obvious freshly turned earth.
Common Mistakes
- Measuring depth to the bottom, not the lid. The parent article’s 45 cm minimum is below the surface; this article measures it to the top of the container.
- A hole in a wet spot. A sealed container sitting in water fails at the seal first.
- Leaving a mound. If the soil will not all go back, take the extra away.
- Digging where the ground has a history. Do not dig on dumps, old fuel sites, graveyards or where anything unknown was buried.
- Putting moist or home-canned food in the bucket. See the danger note below.
Safety
Botulism, collapsing holes and what you might hit
A sealed, buried, cool container is the exact condition in which Clostridium botulinum produces toxin in moist or low-acid food that was not heat-processed. Bury dry staples only. Treat any bulging, hissing or foul-smelling container found later as lethal, not spoiled; do not taste, open it indoors or feed it to animals; see Food Safety. Do not dig a deep hole alone in loose or wet soil, since the sides can collapse, and keep out of old foundations, cellars and buried services. Digging in heat is hard work: drink and rest to avoid heat illness.
What’s Next
- Learn next: Location Selection — where to dig
- Combine with: Retrieval Under Pressure — getting it back out when it matters