Quick verdict
A pair of 18 inch spiral-slotted tubes, 2 inches across, buried beside a tree or shrub with a 1 gallon per hour emitter in the top, so drip water and liquid feed go straight to the root zone instead of the surface, where the maker says up to 40 percent is lost to evaporation and runoff. Unlike a probe you push in and pull out, these stay in the ground and connect to a drip line, which makes deep watering automatic. Two tubes serve one tree or two shrubs.
Strengths
- Delivers drip water and feed 18 inches down at the roots
- Stays in the ground and connects to a drip line
- Spiral slots release water along the tube length
- Reduces surface evaporation and runoff
- Feed poured in the top reaches roots directly
Weaknesses
- Two tubes is one tree; an orchard needs many
- Must be installed at planting or by augering beside an established tree
- Slots can silt in fine soil over years
The overall YardToolLab Score is out of 100. Section scores are out of 10.
Drip Water That Goes Down, Not Across
A drip emitter on the surface beside a tree wets a saucer of soil that the sun dries by afternoon. A tube that carries the drip 18 inches down puts the same gallon where the roots are. VermisTerra’s HydroSpiral tubes are 2 inch spiral-slotted tubes with a 1 gallon per hour emitter in the top, buried in pairs beside a tree or shrub and connected to the drip line, so deep watering happens every time the timer runs.
This review is based on the maker’s specifications and on how buried deep root irrigation tubes perform generally. We have not used these tubes ourselves.
Installation
At planting, stand two tubes at the edge of the root ball on opposite sides, tops at the surface, and backfill. For an established tree, auger two holes at the drip line, drop the tubes in and firm soil around them. Connect each emitter to the quarter-inch drip line. The job is ten minutes per tree and the tubes stay for the life of the planting.
What It Changes
Water releases along the spiral slots through the root zone and none sits on the surface to evaporate or run off; the maker puts the saving at up to 40 percent. Roots grow toward the water, which is deep, so the tree develops a deep system that rides out drought and anchors it in wind. Liquid feed poured in the top reaches roots without feeding the weeds.
Scale
Two tubes is one tree or two shrubs. A hedge or an orchard wants a pair per plant, which adds up; for a few specimen trees and the roses it is a modest investment that lasts.
Maintenance
Mulch over the openings so leaves do not fill the tubes. Rinse each tube with a hose once a season to clear any silt from the slots. Check the emitters when the drip system is flushed in spring.
Who Should Buy It
- Anyone planting trees on a drip system.
- Owners of established trees in drought regions.
- Rose and shrub growers who feed through the roots.
Common Owner Complaints
The cost of many pairs and augering beside old trees. Prioritise specimen trees; rent an auger.
Technique Tips
Set the tube tops level with the mulch surface so they are not tripped on and the emitter is reachable. Run the quarter-inch line to the emitter under the mulch and stake it. For a tree on a slope, put the tubes on the uphill side where water would otherwise run past. Note the tube positions on the garden plan; years later a spade will find them.
Alternatives to Consider
The enomol stainless deep root probe for occasional manual deep watering. Tree watering bags for new trees without drip. A ring of dripline at the drip line for mature trees.
Verdict
For trees and shrubs on a drip system, buried root tubes turn every cycle into a deep watering and train roots down where they belong. Install at planting, mulch the tops and the trees will show it in dry summers.
Full specifications
VermisTerra HydroSpiral 18 Inch Deep Root Irrigation Tubes, Pair, 2 Inch Diameter with 1 GPH Emitter FAQs
At planting, set two tubes vertically at the edge of the root ball on opposite sides. For an existing tree, auger two holes at the drip line, drop the tubes in and backfill. Connect the emitter to the drip line.
Roots follow water. Surface watering keeps roots shallow and the tree thirsty; water at 18 inches trains roots deep, which makes the tree drought tolerant and stable.
Pour diluted liquid fertiliser or compost tea into the top and it goes straight to the root zone with no waste on the surface.
Fine silt can enter the slots over years. A rinse from a hose down the tube clears it. Mulch over the top opening keeps debris out.
