Passive Earth · Tree Guardian — back to home

How it works

A drop-in establishment kit that installs in minutes

The tree bag + drop-in irrigation system provides continuous moisture for 7–10 days per fill and improves soil biology with inoculated biochar and mycorrhizal fungi. Crews plant exactly as they do now: the kit drops into the pit at planting, alongside standard practice.

Four steps at planting

Crew digging the tree pit
1 · Dig at planting
Placing the hydration pillow in the pit
2 · Place the pillow
Connecting the surface bag to the buried pillow
3 · Connect the bag
Watering the root ball mid-install
4 · Fill and walk away

Watch the full install on video — two minutes, shot at the municipal pilot: open on YouTube →

What's in the kit

Tree bag + drop-in irrigation

Meters water into the root ball by wicking, steadily across a 7–10 day window, so the full fill reaches the tree.

Inoculated biochar

Improves water retention and soil structure in the root zone.

Mycorrhizal fungi (AGTIV REACH)

Establishes the below-ground biology that helps roots reach water and nutrients.

Patent pending — full technical details available to qualified partners under NDA. Gravity-fed and nature-based.

Tree Guardian installed on a newly planted oak
Tree Guardian on a newly planted oak at the pilot site.

Against the status quo

Current SystemTree Guardian (Projected)
30% die in first 5 years (Hilbert et al. 2019)20% projected mortality — 10-point improvement
Biweekly crew visits (Park Board operational reality)50% fewer crew visits required
Surface bag drains in 5–9 hrsConsistent moisture across the drying window

Best practice for newly transplanted trees: water daily for the first two weeks, then every 2–3 days through week 12 (University of Minnesota Extension; adopted as policy by Saint Paul Parks) — a schedule no city crew can keep across thousands of trees. The same UMN guidance notes a standard surface bag empties its 14–15 gallons (about 55–68 litres) in 5–9 hours.

Less water, going further. Every litre is hauled to the site by a crew truck. Tree Guardian meters its fill into the root ball across 7–10 days, so the water cities pay to deliver goes into the tree. Water the tree, not the pavement.

See it working in the field, or run the numbers.

Field results The pilot →