Raised Beds & Planters
Raised beds that outlast the garden they're in
Timber rots, metal rusts, and both need replacing. PolyBrick® planters push together in minutes from 100% recycled plastic, and are still doing the job in twenty years.
Why PolyBrick works here
A raised bed lives in the worst possible conditions for a building material: permanently damp on one side, exposed to weather on the other, and in contact with soil that is actively decomposing things.
Timber loses that fight. Even treated, it goes from the inside face where you cannot see it, and the first sign is usually a wall bowing outwards under the weight of wet soil. Corten and galvanised steel look sharp but rust at the base, get very hot in summer, and cost considerably more. Concrete blocks work but need mortar and a bricklayer for anything other than a straight run.
PolyBrick is unaffected by any of it. It does not rot, rust, splinter, shrink or warp, the material is inert and will not leach into growing soil, and it is UV stabilised so it does not go brittle or bleach in the sun.
It also assembles in minutes. Blocks push-fit together, so a bed goes up without tools, mortar or any construction skill: if you can stack blocks, you can build it.
Where this works well
- Vegetable and salad beds
- Ornamental borders and planters
- Herb beds and kitchen gardens
- Allotment plots
- Accessible and waist-height beds
- School and community gardens
- Patio and courtyard planters
- Tree pits and shrub surrounds
At a glance
| Assembly | Push-fit interlock. No tools, no mortar, no fixings |
| Shape | Modular, so beds can be any length, L-shaped, stepped or terraced |
| Base | Firm and level. Open to the ground beneath, or on an existing hard surface |
| Soil contact | Inert. Will not leach into growing soil |
| Material | 100% recycled polypropylene, UV stabilised, made in the UK |
| Compression | Tested to 150 tonnes/m² under fixed static load |
| Service life | 25 years under warranty |
| Maintenance | None. No treating, staining, lining or replacing |
Getting the height right
Bed height is the decision that determines how much you enjoy using it, and it is worth thinking about before you order rather than after.
Low, one or two courses, suits ornamental planting, salad crops and anywhere you mainly want definition and a bit of soil depth.
Mid height is the practical vegetable bed: enough root depth for most crops, deep enough to warm early in spring, and a comfortable height to sit on the edge while you work.
Waist height changes who can garden. No kneeling, no bending, and reachable from a wheelchair or a stool. If anyone using the garden has limited mobility, this is transformative, and it is the single most common thing people wish they had done. Keep the width narrower so the middle is still reachable from one side.
Remember that soil is heavy and a deep bed holds a great deal of it. For anything unusually tall, tell us the dimensions and we will advise rather than guess.
How it goes together
- Choose the position: most vegetables want sun, and a bed against a fence is only reachable from one side, so allow for that in the width.
- Clear and level the ground where the bed will sit. It does not need to be a construction-grade base, but it does need to be flat and firm, because the first course sets everything above it.
- Lay the first course and check it with a spirit level in both directions. On a slight slope, dig into the high side rather than packing up the low side.
- Build up in courses, pushing blocks together and staggering the joints between courses. A tap with a rubber mallet seats them fully.
- Cap the top course for a clean finish and a comfortable edge to sit on.
- Fill: coarse material at the base if the bed is deep, then a good topsoil and compost mix. Fill in stages and let it settle rather than filling to the brim in one go.
Filling a deep bed economically
Buying enough topsoil to fill a tall bed to the top is expensive and unnecessary, because most crops never root that deep.
Fill the bottom third with coarse woody material, turf turned upside down, or clean rubble if drainage is the priority. It breaks down slowly, feeds the bed from below, and saves a great deal of bought soil. Then good topsoil and compost above it, which is the layer the plants actually use.
Expect the level to drop over the first year as the base settles and organic matter breaks down. Top up in the second spring rather than overfilling at the start.
Drainage and the ground beneath
Where the bed sits on soil, leave it open to the ground. Roots can go deeper than the bed itself, worms move in and out, and water drains away naturally. Loosen the soil at the base before you fill.
Where the bed sits on a patio, a path or another hard surface, it needs somewhere for water to go, or the bottom of the soil stays saturated and roots drown. A layer of coarse material at the base helps, and raising the bed very slightly on the hard surface lets water escape at the bottom rather than sitting in it.
Shapes, runs and adding on later
Because the system is modular, the bed does not have to be a rectangle. Turn corners, step it down a slope, run an L along two boundaries, or build a series of narrow beds with paths between them.
It also means you are not committing to a final layout on day one. Beds can be extended, shortened or reconfigured later, and blocks from a bed you no longer want go into the next project rather than into a skip. That is a genuine advantage over anything built with mortar or screws.
Get it right first time
The one thing worth knowing: make the paths between beds wider than you think.
Everyone maximises growing space and regrets it. A path that is comfortable when the beds are empty is impassable in July, when everything is leaning over the edges and you are trying to get a wheelbarrow between them.
Allow enough width for a barrow with room either side, and more where you will kneel to work. Growing space you cannot reach is not growing space, and it is far easier to plan generously now than to move an established bed later.
Ask our engineer
Questions about bed heights, filling, or planning a layout? Ask below, or get in touch directly.
Common Questions
Is recycled plastic safe for growing vegetables?
Yes. The material is inert recycled polypropylene and will not leach into growing soil. Unlike some treated timbers there is nothing applied to the surface that can move into the bed, and unlike metal there is nothing to corrode.
It locks the waste plastic up rather than releasing it.
How long will a PolyBrick raised bed last?
25 years under warranty. There is nothing to rot, rust, splinter, shrink or warp, and the material is UV stabilised so it does not go brittle or bleach in sunlight.
It needs no treating, staining or lining at any point.
Do I need tools to build a raised bed?
No. Blocks push-fit together, and a tap with a rubber mallet seats them fully. There is no mortar, no screws and no cutting, so a bed goes up in minutes rather than days and needs no construction skill.
What base does a raised bed need?
Flat and firm ground. It does not need a construction-grade base, but the first course sets everything above it, so level it properly and check with a spirit level in both directions.
On a slight slope, dig into the high side rather than packing up the low side.
How deep should a raised bed be?
Low beds suit ornamental planting and salad crops. Mid height is the practical vegetable bed: enough root depth for most crops, warms early in spring, and comfortable to sit on the edge while working.
Waist height removes kneeling and bending entirely and can be worked from a wheelchair, which is the single most common thing people wish they had done.
What is the cheapest way to fill a deep bed?
Fill the bottom third with coarse woody material, upturned turf, or clean rubble where drainage matters. It breaks down slowly, feeds the bed from below and saves a great deal of bought soil.
Good topsoil and compost go above it, which is the layer plants actually use. Expect the level to drop in the first year and top up the following spring.
Can I build a raised bed on a patio?
Yes, but the water needs somewhere to go, or the bottom of the soil stays saturated and roots drown. A layer of coarse material at the base helps, and raising the bed very slightly on the hard surface lets water escape rather than sitting in it.
Where the bed sits on soil instead, leave it open to the ground.
Can I extend or move a bed later?
Yes. Because the system is modular and there is no mortar or fixings, beds can be extended, shortened or reconfigured, and blocks from a bed you no longer want go into the next project rather than into a skip.
You are not committing to a final layout on day one.
Do the beds need lining?
No. There is nothing to protect: the material does not rot or corrode and does not need separating from wet soil, which is why timber beds are often lined.
Leave the base open to the ground where you can, so roots can go deeper and worms can move in and out.
