Step 2 - Soil & Fill
How to Fill a Raised Garden Bed Cheaply
Most of a deep bed can be filled with material people give away. Only the top foot has to be bought.
Janet H. - the hands-on owner behind Janet Media Group.
Published - last updated
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On a 17-inch bed, roughly two-thirds of the volume is below the root zone and can be filled with material you can get free. That is the whole strategy: buy quality mix only for the top 10 to 12 inches, and fill the rest with what is available locally.
Where free fill comes from
| Material | Where to get it | Use it for | Watch out for |
|---|---|---|---|
| Fallen leaves | Your yard in autumn; neighbors will often give bags away | Middle layers, and leaf mold later | Compacts into a mat -- mix with coarser material |
| Wood chips | Tree surgeons frequently drop loads free | Bottom layer and paths | Keep them out of the top growing layer -- they tie up nitrogen as they break down |
| Logs and prunings | Your own garden, storm debris | Bottom layer on deep beds only | Avoid black walnut, and avoid treated or painted wood |
| Spent potting soil | Last season's containers | Middle layers | Do not reuse soil from diseased plants |
| Cardboard | Any delivery | Ground layer, and between coarse layers | Remove tape and glossy labels |
| Grass clippings | Your own mowing | Middle layers, in thin layers | Thick wet layers go slimy; alternate with browns |
The cheap fill plan
- 1
Cardboard on the ground
Free, smothers the grass, and disappears within a season. Do this even on a bed you are filling entirely with bought mix.
- 2
Logs and branches, 4 to 6 inches
Only on beds deeper than about 15 inches. They rot slowly, hold moisture and displace a serious amount of purchased volume.
- 3
Leaves, clippings and cardboard, 4 to 8 inches
Alternate wet green material with dry brown material so it does not pack into a slimy mat. Tread it down and water it.
- 4
Spent potting soil and any topsoil you have
Bring the level to about 12 inches below the rim. If you need to buy at this stage, buy bulk rather than bags.
- 5
Buy the top 10 to 12 inches
This is the layer that is not worth economizing on. A decent raised bed mix here, over free material below, grows the same crop as a bed filled entirely with bought mix.
What the cheap approach actually costs you
Settling, mainly. A bed built on leaves and branches will drop noticeably more in its first year than one filled with mineral soil, so budget for a top-up in spring. Organic material also ties up some nitrogen while it decomposes, which is why the wood stays well below the root zone.
And time. Collecting bags of leaves and waiting for a wood chip delivery is slower than ordering soil. If the bed has to be planted next weekend, some of this will not be available to you.
The free fill that costs nothing forever
Everything above is a one-off saving. The recurring one is compost: a bed wants an inch or two every spring, and a bin turns waste you already produce into exactly that. Composting for beginners is the place to start, and the hugelkultur method is the fullest version of the woody-base approach.
What to buy
The products that fit the advice above, chosen by the process on our how we choose page. We have not hands-on tested them; specifications are the manufacturers’ own.
Quick picks
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  Top pickEspoma Organic Raised Bed MixPurpose-made raised bed mix, widely stocked | The simple bagged default | 8.7 | Check price on Amazon |
| 2 |  FoxFarm Raised Bed Planting MixHeavier blend formulated for beds, not pots | Bed-scale FoxFarm | 8.6 | Check price on Amazon |
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Scores are our own editorial judgment, formed from published specifications and independent sources. They are not aggregated customer ratings, and they are not the result of hands-on testing, which we do not currently do. See how we choose.
Common questions
What is the cheapest thing to fill a raised bed with?
Material you can get free: fallen leaves, wood chips from a tree surgeon, logs and prunings, spent potting soil and cardboard. Use them for everything below the top 10 to 12 inches, and buy a proper growing mix only for that top layer.
Can I fill a raised bed with leaves?
In the middle layers, yes -- leaves break down into excellent material. Mix them with coarser stuff so they do not compact into a wet mat, and keep them below the root zone. Expect significant settling in the first season as they decompose.
Can I put wood chips in the bottom of a raised bed?
Yes, in the bottom layer where roots will not reach them. Wood chips tie up nitrogen as they break down, which is a problem in the growing layer and harmless several inches below it. Avoid black walnut, which contains juglone and inhibits tomatoes.
Is it bad to fill a raised bed with free material?
Not at all, provided the top 10 to 12 inches is a proper growing mix. The trade-offs are more settling in year one and a wait while you gather materials. Never economize on the growing layer -- that is where the whole crop happens.
Sources
Factual claims on this page are backed by the published sources below, and product specifications are the manufacturers’ own. Where a figure is not published, we say so rather than estimating it.