Making Raised Beds on an Allotment

Raised beds are one of the best upgrades you can make on an allotment. They improve drainage, warm up faster in spring, reduce soil compaction, and make crop rotation and maintenance far easier. Whether you build with timber, reclaimed pallets, or pallet collars, a well-made raised bed can last for years and dramatically improve yields.

This guide explains how to plan and build raised beds, compares construction options (including pallets and pallet collars)

🌱 Why Use Raised Beds?

Raised beds help you:

• improve drainage on heavy or compacted soil

• warm soil earlier in spring

• reduce weeds and soil compaction

• control soil quality and fertility

• garden more comfortably (less bending)

They’re especially useful on new or poor-quality plots.

📐 1. Planning Your Raised Bed (Do This First)

Ideal Dimensions

• Width: 90–120cm (reachable from both sides)

• Length: 2–3m (manageable and flexible)

• Height: 20–30cm (standard), 40–60cm (deep-rooted crops or access)

Avoid making beds too wide — access matters more than size.

Positioning Tips

• Align beds north–south where possible

• Leave paths 45–60cm wide

• Consider water access and wheelbarrow space

🪵 2. Traditional Timber Raised Beds

Materials

• Untreated hardwood (oak, larch) – longest lasting

• Treated softwood – cheaper, shorter lifespan

• Exterior screws (galvanised)

⚠️ Avoid old railway sleepers treated with creosote.

How to Build (Step-by-Step)

1. Cut boards to size

2. Screw boards into a rectangular frame

3. Peg or stake corners for stability

4. Place on level ground

5. Fill in layers (see filling section below)

Pros

• Durable

• Custom sizes

• Neat appearance

Cons

• Higher cost

• More tools needed

♻️ 3. Pallet Raised Beds (DIY & Low Cost)

Pallet beds use dismantled pallets to build a timber frame.

Best Pallets to Use

• Heat-treated pallets marked HT

• Avoid chemically treated pallets

How to Build

1. Dismantle pallets carefully

2. Use planks to build a rectangular frame

3. Reinforce corners and edges

4. Line interior with membrane (optional)

Pros

• Cheap or free

• Recycled materials

• Customisable

Cons

• Time-consuming

• Variable timber quality

• Shorter lifespan

👉 Best for temporary or starter beds.

📦 4. Pallet Collars (Fastest & Easiest Option)

Pallet collars are foldable wooden frames that sit on pallets.

Why They’re Popular

• No tools required

• Stackable for height

• Easy to move or remove

How to Use

1. Place collar directly on soil

2. Stack 1–3 collars for depth

3. Line with cardboard if needed

4. Fill and plant

Pros

• Very quick setup

• Modular

• Ideal for beginners

Cons

• Fixed size

• Timber quality varies

🧱 5. Preparing the Ground Under Raised Beds

Don’t skip this step.

Best Practice

• Remove perennial weeds

• Lay cardboard (weed suppression)

• Place bed frame on top

Avoid plastic underneath — it traps water and roots.

🌿 6. Filling Raised Beds (Layering Method)

Base Layer (Optional)

• Cardboard or newspaper

• Logs or woody material (for deep beds)

Middle Layer

• Garden waste

• Leaves or compostable material

Top Layer (Most Important)

• Good quality topsoil

• Compost or well-rotted manure

Aim for 60–70% soil, 30–40% organic matter.

💧 7. Watering & Maintenance

Raised beds:

• Drain faster

• Warm faster

• Dry out faster

Tips

• Mulch heavily

• Water deeply

• Install drip irrigation if possible

Top up compost annually as beds settle.

🌾 8. What Grows Best in Raised Beds?

Excellent for:

• salads

• carrots and beetroot

• onions and garlic

• strawberries

• herbs

Deep beds suit:

• potatoes

• parsnips

• squash

⚡ Quick Raised Bed Tips

• Build once, build strong

• Keep beds narrow for access

• Mulch every season

• Top up soil yearly

• Avoid treated or unknown timber

🧠 Key Raised Bed Principles

• Access matters more than size

• Soil quality beats depth alone

• Raised beds need more watering

• Replenish organic matter yearly

Photo by Duc Van on Unsplash