Materials
Cedar Raised Garden Beds
Cedar is worth it for most gardeners. Its heartwood resists rot without chemicals, so an unsealed cedar bed usually lasts 10 to 15 years or more, at roughly two to three times the lumber cost of untreated pine.
Raised Gardening Beds is owned by the team behind Thrive Garden, which sells some of the products linked on this page.
| Question | Short answer |
|---|---|
| Typical lifespan | About 10–15+ years (heartwood boards) |
| Rot resistance | Good, from natural extractives in the heartwood |
| Lumber for a 4x8 bed, 11 in tall | Six 8-ft 2x6 boards; roughly $150–$350 |
| Needs a finish? | No; optional oil on outer faces only |
| Main weak point | Corners and soil-contact edges, which stay wet |
| Compared with pine | Two to four times the life for two to three times the cost |
Why cedar resists rot
Rot is caused by fungi that feed on wood fibers when the wood stays damp. Cedar heartwood, the darker reddish core of the log, is loaded with natural compounds that fungi and many insects avoid. That is why cedar can sit against moist soil for years without any chemical treatment.
The catch is that only the heartwood has this protection. Sapwood, the pale cream-colored outer band, rots about as fast as pine. When you buy boards, pick ones that are mostly red-brown all the way across the end grain. A streak of pale wood on one edge is fine; a board that is half sapwood is not.
Cedar is also light, stable and easy to cut and screw, so it bows and splits less than many cheaper woods as it goes through wet and dry seasons.
How long a cedar raised bed lasts
Most cedar beds last 10 to 15 years, and well-built ones in dry, well-drained spots can pass 20. Three things shorten that:
- Constant wet soil. Beds in low spots or on heavy clay stay soggy and wear out first.
- Thin boards. A 1-in (actual ¾-in) board fails years before a 2-in (actual 1½-in) board.
- Sapwood. Pale boards may need replacing in five years.
The corners usually go first, because end grain soaks up water like a straw. Setting the bed on a few inches of gravel at the corners, or using a 4x4 cedar post inside each corner, adds years. When a single board fails, you can usually swap just that board and keep the rest.
Western red vs eastern red cedar
These are two different trees, and both work for beds.
Western red cedar is the one most lumberyards stock across the country. It is light, straight-grained, mild in scent and easy to work. Boards come in standard sizes like 2x6, 2x8 and 2x10, smooth or rough-sawn.
Eastern red cedar is actually a juniper that grows across the eastern and central US. Its heartwood is a deeper purple-red, very aromatic and highly rot resistant. It tends to be knotty and comes in narrower or rough-cut boards from small local sawmills, so sizes vary. If a mill near you sells it at a fair price, it makes a sturdy, long-lived bed.
Either way, heartwood content matters more than which species is on the label.
What a cedar bed costs
Prices swing a lot by region and grade, so treat these as rough ranges for lumber only:
- 4x8 bed, 11 in tall (two 2x6 boards high): six 8-ft boards, roughly $150–$350.
- 4x8 bed, 14½ in tall (two 2x8 boards high): roughly $250–$450.
- 4x4 bed, 11 in tall: four 8-ft 2x6 boards cut in half, roughly $100–$230.
Add $15–$30 for exterior screws and corner posts. Knotty or "rustic" grades cost less than clear grades and grow vegetables just as well. Rough-sawn boards are often thicker than planed ones, which helps them last.
For how cedar stacks up against pine, redwood and treated lumber on price per year, see the best wood for raised beds.
Should you seal or line cedar?
You don't have to do either. Cedar was chosen precisely because it does fine bare. Left alone, it weathers to a soft silver-gray in a year or two; that color change is only on the surface.
If you want to keep the warm color or slow surface checking, brush raw linseed oil or a plant-safe exterior oil onto the outside faces and top edges only. Skip stains and sealers that list fungicides or mildewcides, and keep any finish off the inner faces that touch soil.
Lining is optional too. Some gardeners staple heavy plastic sheeting to the inside walls (not the bottom) to keep wet soil off the boards. It can help in very rainy regions, but it can also trap moisture against the wood if water gets behind it, so make sure the top edge is tucked under the soil line and the bottom is left open to drain.
Building vs buying a cedar bed
Building your own is simple: cut the boards to length, screw them to 4x4 corner posts, and set the frame level. Expect a basic 4x8 to take a few hours using only a circular saw and a cordless drill. Our step-by-step build guide walks through it.
Buying a cedar kit saves cutting and usually uses interlocking corners, but many kits use boards thinner than ¾ in, which shortens their life. If you buy, check the actual board thickness and whether the wood is mostly heartwood. Our guide to choosing the best raised garden bed covers what else to compare.
If you'd rather not maintain wood at all, a galvanized metal bed is one option. The full trade-off is laid out in metal vs wood raised beds.
How to choose
Cedar makes sense when
Your goal is a natural-looking bed that needs no treatment and will last a decade or more, and the higher lumber cost fits your budget.
Choose a cheaper wood if
The bed is a trial or you may move in a few years. Untreated pine lasts 3 to 7 years for far less money.
Check the boards
Look at the end grain. Mostly red-brown heartwood and a full 1½-in thickness give the longest life.
Plan the corners
Use 4x4 posts or heavy brackets at the corners, the first place a cedar bed weakens.
Related guides
- Cedar, redwood, pine and treated lumber compared
- Is metal a better choice than cedar?
- Building a wooden bed step by step
- Choosing a raised bed: the full checklist
- Free plans with cut lists
Is cedar safe for growing vegetables?
Yes. Cedar's natural oils stay in the wood and are not considered a concern for vegetables grown in the soil beside it. Just avoid adding chemical stains or sealers to the inside faces of the bed.
Does cedar need to be treated before building a bed?
No. Untreated cedar is the point of using cedar. An optional coat of raw linseed oil on the outer faces keeps the color longer, but it does not change how long the boards resist rot by much.
Why is my cedar bed turning gray?
Sunlight breaks down the surface fibers and the color fades to silver-gray within a year or two. It is cosmetic and doesn't mean the wood is rotting. Rot shows up as soft, crumbly wood you can push a screwdriver into.
Ready to buy a raised bed?
Thrive Garden sells galvanized metal raised beds and fabric beds in several sizes.
Raised Gardening Beds is owned by the team behind Thrive Garden, which sells some of the products linked on this page. Read our disclosure.