Large Bulb Auger (4” x 28”)

4 Inch Auger Bit for Large Bulbs, Bedding Plants and Post Holes

Effortlessly plant large bulbs and bedding plants with our high-performance 4-inch auger bit. This professional-grade, heavy-duty bulb planter is designed for efficiency, featuring double 10-gauge flighting that enhances digging power. Whether you're a professional landscaper or a weekend gardener covering extensive ground, this auger simplifies your work. Simply attach the 4-inch bulb auger to your drill, and you're ready to dig! Opt for the Heavy Duty version for tackling densely compacted soil or rocky terrain. Compatible with ½-inch drills.

Need a narrower or wider hole? Browse all bulb augers, or step up to the Quart Pot Landscaping Auger (5" x 28").

The Ultimate Bulb Planting Tool

Powerful and efficient, our Large Bulb Auger is the ideal tool for planting bulbs and digging post holes with ease. Measuring 4 inches in diameter and 28 inches in length, it features a durable 1-inch shaft made of 100% steel. Choose between a Light-Medium Duty auger for home gardening or a Heavy Duty auger for professional landscaping.

For optimal performance, we recommend using this 4-inch auger with a 1/2-inch, 18V cordless drill with a larger battery (higher Ah). This auger is designed to fit ½-inch drills, and our cordless electric drill bundle provides the necessary power along with a bonus battery and storage box—available exclusively from Power Planter! If using the heavy-duty variant with a Stihl BT45 Powerhead, be sure to purchase the threaded adapter for compatibility. Never use an impact driver with an auger. See which drill fits this auger.

Light-Medium or Heavy Duty: Which 4" Auger Do I Need?

Our Heavy Duty auger is the toughest and most versatile option available. Use the dropdown menu above to select the “Heavy Duty – Clay, Rocky, or Professional Use” option. This version includes a rugged hex adapter with a replaceable auger tip, allowing you to tackle the most demanding digging jobs without compromising the main auger. Additionally, the replaceable auger blades at the leading edge ensure easy maintenance and long-lasting performance.

For added flexibility, this auger bit is compatible with any drill (including Stihl BT45) featuring a threaded end when used with a separately sold threaded adapter. Our heavy-duty augers include two mounting holes with pins for secure attachment and are designed to fit auger powerheads with a 3/4-inch shaft—perfect for professional landscapers who need to switch between drills and powerheads throughout the day.

Specifications

FAQs

What drill do I need for a 4 inch auger bit?

A 1/2" 18V cordless drill with a larger battery (higher Ah). We recommend cordless drills only, and never an impact driver.

Do I need an adapter?

No. The Large Bulb Auger ships with a 1/2" hex adapter installed, so it goes straight into your drill. For a Stihl BT45 or another powerhead, see our auger adapters.

Light-Medium or Heavy Duty?

Choose Light-Medium Duty for home use in loose garden soil. Choose Heavy Duty for clay, rocky soil or professional use; its tip and cutting blades are replaceable.

What can I plant with a 4" auger?

Large bulbs, bedding plants, 3-inch potted plants, bare root trees and shrubs. It also bores under a sidewalk for a gutter extension and clears clogged PVC drain pipes. See the auger size guide to compare sizes.