Yes, you can install a mailbox post without concrete. The three no-dig mailbox post options are a screw-in ground anchor such as the Mayne No Dig Ground Anchor, a surface-mount base plate bolted to an existing curb or sidewalk, and a driven post spike. A fourth route, a dug hole backfilled with gravel and tamped soil, skips concrete but not digging.
Each works in the right conditions and fails in the wrong ones. Below we cover how each one installs, which soils and mailboxes they suit, and when you should pour concrete after all. The hardware is in our mailbox post accessories and mailbox post collections.
No-dig mailbox post options compared
| Method | Installs into | Post | Best for | Avoid when |
|---|---|---|---|---|
| Screw-in ground anchor | Soil, twisted in by hand | 4 x 4 wood (and sleeve posts over it) | Standard or clay soil, light to medium boxes | Rocky or very sandy ground |
| Surface-mount base plate | Existing concrete or asphalt | Matching steel post | Curbs, sidewalks, paved road edges | Thin, cracked or crumbling concrete |
| Driven post spike | Soil, hammered in | 4 x 4 wood | Firm, rock-free soil, light boxes | Rocks, buried roots, heavy or locking boxes |
| Gravel and tamped soil | Dug hole, no concrete | Any in-ground post the maker allows | Breakaway-friendly installs, easy future replacement | Loose sand; posts whose maker calls for concrete |
Option 1: Mailbox post anchor (screw-in ground anchor)
A screw-in mailbox post anchor is a steel auger with a square bracket on top. You twist it into the ground, then bolt a 4 x 4 into the bracket. No hole, no mixing, and the post is ready for the mailbox the same day.
The Mayne No Dig Ground Anchor is the one we sell. Verified from the product page:
- Galvanized steel
- Holds a standard 4 x 4 wood post (not included)
- Includes 5 lag bolts and a 20 inch length of rebar that you use as the twisting handle
- Works with any Mayne mail post
- Best suited for standard soil conditions; not recommended for rocky or extremely sandy ground
How to install a mailbox post with a ground anchor
- Call 811 first. An anchor goes into the ground just like a post does, so have buried lines marked a few business days ahead.
- Mark the spot. Measure the 6 to 8 inch setback to where the mailbox door will be, not to the post, and allow for your arm or bracket.
- Start the anchor plumb. Stand it on the mark, slide the rebar through the top and begin turning. Check plumb on two sides with a level every few turns; it is much easier to correct early than once it is deep.
- Drive it to grade. Keep turning until the bracket sits at ground level, or as Mayne's instructions direct. If you hit a rock, back it out and move a few inches rather than forcing it.
- Set the 4 x 4. Cut the post so the mail entry will end up 41 to 45 inches above the road surface, then seat it in the bracket.
- Check height and level, then bolt. Confirm the post is plumb and at the right height before you drive the included lag bolts.
- Add the post and box. Slide on a sleeve post such as the Mayne Liberty, or mount the box to the 4 x 4 directly.
For the height math, see our mailbox post buying guide.
Option 2: Surface mount base plate
If concrete runs right to the road, you do not need soil at all. A surface-mount base plate bolts to the concrete with masonry anchors, and the post bolts to the plate.
The Mail Boss Surface Mount Base Plate is galvanized steel with a powder-coated finish in black, granite, bronze or white. It secures a post to hard surfaces such as concrete or asphalt, is generally paired with the 27 inch surface-mount post, and is compatible with all Mail Boss posts, including the in-ground post.
Mail Boss's base plate instructions:
- Confirm placement and height with your post office or carrier.
- Mark the sidewalk about 17 inches back from the street edge and center the plate on the mark.
- Drill 8 holes through the plate's holes with a masonry bit, or use self-tapping masonry screws.
- Fix the plate with 8 masonry anchors; 1/4 x 3 inch outdoor masonry screws are typical.
- Bolt the post to the plate (the plate ships with 4 mounting bolts), then check plumb and height.
With the 27 inch post, the curb height counts toward your mail height: on a 4 inch curb, a Mail Boss box ends up with its slot about 42 to 44 inches above the road. Our mailbox post buying guide shows the math for taller curbs.
The concrete has to be sound. Anchors in a cracked or crumbling curb will loosen. If there is no slab, a small new pad is an option, though at that point you are pouring concrete anyway.
Option 3: Mailbox post spikes
A post spike is a pointed steel stake with a square socket on top. You hammer it in with a driving tool or a scrap block, then drop the 4 x 4 into the socket and tighten its bolts. Spikes are quick and cheap, but they need firm soil free of rocks and roots, and they are hard to correct if they go in crooked. We treat them as a light-duty option for simple wood posts and small boxes. For a heavier box, a screw-in anchor or concrete holds better.
Option 4: Gravel and tamped soil, no concrete
This is the traditional way to set a wood 4 x 4 without concrete. Dig the hole (USPS says to bury the post no more than 24 inches deep), put about 6 inches of gravel in the bottom, stand the post, then add soil a few inches at a time and tamp each layer hard. It gives way more easily if a car hits it, and the post is easy to pull out later. Whitehall's Balmoral instructions use packed earth by default and treat concrete as optional, noting that some local Post Offices or county road commissions do not allow concrete backfill.
Match the post to the base before you order
Pairing the wrong post with the wrong mount is a mix-up we catch before orders ship. In-ground post orders outnumber surface-mount by about four to one, and some of those buyers later decide to bolt to a slab instead.
- Mail Boss 43" in-ground post: set in concrete about a foot deep, so it does not suit a no-concrete install.
- Mail Boss 37" and 27" posts: bolt to a base plate, sold separately, on a concrete pad or sidewalk.
- A base plate on a 43" post: it fits, but it can leave the box too high for the carrier.
- Sleeve-style posts, such as Whitehall: slide over a wooden 4x4 that you supply. Sleeves are made for a standard 4x4, which measures about 3.5" across, and not a rough true 4x4.
We have stopped orders that paired a 43" in-ground post with a base plate to check with the buyer first. Also plan on separate deliveries: anchors and posts can arrive in a different carton from the mailbox, sometimes on a different day.
When a no-dig mailbox post is a bad idea
- Heavy locking or steel mailboxes. A loaded locking box on a short post puts a lot of leverage on the base. Mail Boss designs its in-ground steel post to be set in concrete, and its surface-mount posts go on a bolted base plate.
- Rocky, very sandy or loose soil. Mayne itself does not recommend its anchor for rocky or extremely sandy conditions. In loose ground, the anchor or spike can tilt over time.
- Snowplow routes and tight corners. A post that takes regular knocks will work an anchor loose. Set it back as far as your postmaster allows.
- Long arms and wide multi-box posts. The further the box sits from the post, the more twisting force on the base. Check the post maker's box weight limit; the Mayne Liberty, for example, is best suited to boxes under 16 lbs.
In those cases, follow the concrete steps in our mailbox installation guide. If the decision is between doing it yourself or hiring it out, our mailbox installation cost guide lays out both.
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Find anchors, caps and cuffs in mailbox post accessories, or browse mailbox posts. Questions about your soil or your mailbox's weight? Contact us.
No-dig mailbox post questions
Do you sell a post extender if the post ends up too low?
We do not. Check the height against the 41 to 45 inch range before concrete sets or an anchor is fully driven, because it is much harder to fix afterward.
Can you install a mailbox post without concrete?
Yes. Use a screw-in ground anchor, a surface-mount base plate on existing concrete, a driven post spike, or a dug hole backfilled with gravel and tamped soil. Pick based on your soil and how heavy the mailbox is.
How does a no-dig mailbox post anchor work?
You twist a galvanized steel auger into the ground until its bracket sits at grade, then bolt a 4 x 4 into the bracket. The Mayne No Dig Ground Anchor uses an included length of rebar as the handle and 5 lag bolts.
Are mailbox post spikes strong enough?
For a light box on a wood post in firm, rock-free soil, usually. For heavy locking mailboxes, loose soil or plow routes, a screw-in anchor, base plate or concrete footing is the safer choice.
Do I still need to call 811 for a no-dig anchor?
Yes. Anchors and spikes go into the ground just like a post does. Contact 811 a few business days before you start so utilities can mark buried lines.
Can a surface mount base plate go on asphalt?
Mail Boss says its base plate secures a post to hard surfaces such as concrete or asphalt. The surface must be sound; anchors in cracked or crumbling pavement will loosen.
******It is always recommended to contact your local postmaster prior to installation. While most of our mailboxes are USPS-approved your local postmaster may have specific preferences in terms of mailbox types and installation location******
