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Auger drill for planting bulbs

Updated: 22 October 2026

A trowel is slow once you have a bag of tulips and an 18 V drill in the shed, and an auger drill for planting bulbs only helps if the hole matches the bulb. The shaft length is not the planting depth. A 150 mm fence-post machine is the wrong width for a crocus. This page stays with bulbs, plugs and small plants in soil you can work. Joists and specified fence posts stay on the main [auger drill comparison](/hub/drilling-and-accessories/auger-drill). Listings were checked on 19 October 2026, with the RHS guide to planting bulbs. We did not plant a trial border. A qualifying purchase can earn a commission at no extra cost to you.

A trowel is slow once you have a bag of tulips and an 18 V drill in the shed, and an auger drill for planting bulbs only helps if the hole matches the bulb. The shaft length is not the planting depth.

Our top picks

WORKPRO WORKPRO green set, 4 x 22 cm and 8 x 30 cm

Best overall

WORKPRO WORKPRO green set, 4 x 22 cm and 8 x 30 cm
9.0/10about £13.99
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WORKPRO WORKPRO green set, 4 x 42 cm and 9 x 40 cm

Alternative

WORKPRO WORKPRO green set, 4 x 42 cm and 9 x 40 cm
9.0/10about £16.99
View offer
Thrink Thrink 30 mm x 60 cm planting auger

Alternative

Thrink Thrink 30 mm x 60 cm planting auger
9.0/10about £7.99
View offer
On this page
  1. 1.Depth comes from the bulb, not the shaft
  2. 2.About 3 cm, about 4–8 cm, and when 10 cm is already wide
  3. 3.Damp soil, dry clay and stones
  4. 4.After the hole

Depth comes from the bulb, not the shaft

The RHS says most bulbs are planted at about two to three times the height of the bulb, measured to the shoulder. A tulip that is 5 cm tall wants something like 10–15 cm of soil over it, not the 60 cm printed on a Thrink title and not the 80 cm printed on a long LYFETC title. You use the shaft only so the flight can reach that depth and still come back out with the spoil. Stopping at 12 cm on a 42 cm bit is correct. Kickback, clutch and the two-hand grip are on how to use an auger drill bit, so this page does not repeat the whole sequence.

About 3 cm, about 4–8 cm, and when 10 cm is already wide

A 30 mm bit is the narrow end of this set. Thrink’s listing is titled about 3 cm by 60 cm at about £7.99, with 4.4 from 75 reviews. Buyers mention bulbs, soil under dead hedging, and holes for metal arches. That diameter is enough for many bulbs if the shank stays in the chuck. The title says 3/8 inch, the spec says straight, and a review says the end slips. A bit that spins in the chuck does not plant anything. The WORKPRO green set at about £13.99 adds a 4 cm bit for a single bulb and an 8 cm bit for a plug, not a crocus. A 10 cm flight is already wide, and one buyer stopped near 6 inches. The 150 mm Einhell is the wrong hole for a border. Shank and voltage checks are in the buying guide.
WORKPRO WORKPRO green set, 4 x 22 cm and 8 x 30 cm

Testsieger

WORKPRO WORKPRO green set, 4 x 22 cm and 8 x 30 cm
9.0/10about £13.99
View offer

Damp soil, dry clay and stones

Workable soil is the condition hiding inside every cheerful review. Buyers of the long LYFETC 50 mm bit, titled 5 by 80 cm at about £23.99, talk about potatoes and beans in light soil, and about aeration holes in waterlogged clay that they backfilled with sand and gravel. One review limits the bit to damp soil. That is a review, not a moisture percentage, so this page will not invent one. If the clay is dry and cracked, water the line and wait, or accept that the flight will polish a dent and stall. A 4 cm bit does not become a cultivator because you hold the trigger longer.

After the hole

The hole is only finished when the bulb is the right way up and the soil is back around it. Point the nose up, set the shoulder at the depth you planned, and firm the soil so the bulb does not sit in an air pocket under a loose spiral of earth. An auger leaves a round wall. In heavy clay that wall can be smeared smooth, so scratch the sides with a trowel before you backfill, or water will sit in the hole. The RHS planting page is about depth, spacing and the nose. The auger does not replace that. It only removes the soil faster when the ground cooperates.

Common questions

How deep should a tulip go if the auger is 60 cm long?
Follow the bulb, not the shaft. The RHS guide is about two to three times the bulb’s height to the shoulder, so a tulip often wants roughly 10–15 cm of cover, not 60 cm. The Thrink title length of about 60 cm only means the flight can reach a normal bulb depth and still be pulled out.
Is 3 cm wide enough for daffodils?
Often yes, for the bulb itself. A 30 mm Thrink or a 4 cm WORKPRO bit is in the range for daffodils and tulips if you can get the bulb in without snapping the tunic, and if the soil falls back around it.
Will a drill auger work in heavy clay?
Sometimes, and only when the clay is damp enough for the flight to cut. A review of the long LYFETC bit treats damp soil as the workable case, and Einhell buyers describe hedging in heavy clay with the 150 mm machine. Dry, compacted clay stalls a chuck bit, which is also what WORKPRO’s own limit on hard ground is pointing at.
What happens if the flight hits a stone?
The bit stops, and the drill can twist. That is the complaint on the 10 cm LYFETC bit, and it is why WORKPRO says not to use the set on rocks. A small stone at the side of a bulb hole can be pulsed at low speed, which is the suggestion on that 10 cm listing.
Do you need the 150 mm Einhell for a border?
No. The included auger is 150 mm, the tool is about £148.45 without a battery, and a border of bulbs does not want a fence-post hole at each plant. Buyers use it for hedging and for fence posts in clay, which is a different afternoon.
Should the bulb go in nose up after the hole is drilled?
Yes. Set the nose up and the shoulder at about two to three times the bulb’s height, then firm the soil so there is no air gap under the bulb. An auger does not orient the bulb for you. In clay, roughen a smeared hole before you backfill, or water can pool at the bottom.

Related pages

Wood or earth auger

Auger drill

Best auger drill bit for joists, bulbs or fence posts

Auger drill bit buying guide for soil, timber, posts

How to use an auger drill bit without a jammed wrist

Sources

Public UK sources from the research digest, last checked on 19 October 2026. Shelf prices and star lines are the amazon.co.uk figures in the display file.

  1. HSE: PUWER overview (retrieved 19 October 2026)
  2. HSE: hand-arm vibration in tree work (retrieved 19 October 2026)
  3. HSE INDG480: hand-arm vibration (retrieved 19 October 2026)
  4. Control of Vibration at Work Regulations 2005 (retrieved 19 October 2026)
  5. Consumer Rights Act 2015 (retrieved 19 October 2026)
  6. Electrical Safety First: drills (retrieved 19 October 2026)
  7. RHS: planting bulbs (retrieved 19 October 2026)
  8. Einhell UK: GP-EA 18/150 Li BL Solo (retrieved 19 October 2026)