Garden Advice

How to Build a Raised Bed for Your Garden

Fantastic Team
Published: Jul 17/2020
Last update: Jul 17/2024
6min read
Views: 295

If you’re a gardening enthusiast looking for a great way to spruce up your garden and add variety to it, look no further than raised beds! Not only are they easy to maintain, but they can bring a fun look and great structure to your green space. As well as being a great addition to any horticulturists’ garden, they make it easier for gardeners with mobility issues to indulge in their hobby without much effort.

But how do you build a raised garden bed? What do you need and how should you prepare? Worry not! The experts at Fantastic Services are here to give you all the answers!

Table of Contents:

Why build a raised bed?
What plants are best for raised garden beds?
Before you start
Choosing the wood
Preparation
Building
Filling
Building a raised bed on a hard surface
What to keep in mind

So, if you:

Are a novice gardener;
Are a horticulturist suffering from decreased mobility;
Want to know how to make a raised bed garden,

Then read on, because this post is just for you!

Why build a raised garden bed?

There are many reasons why you’d want to incorporate raised beds into your garden design. They are convenient, easy to manage and look great. Not to mention they have a vast array of other good qualities, such as:

Improved drainage.
You can easily control how well the soil drains and how much water it retains when working with raised garden beds.
Control over the soil type.
You can match the soil to the plants you’ll be growing, make your own potting mix, and grow plants that won’t usually thrive in your garden due to the underlying soil. Raised beds give you full control over what you can grow.
Increased soil temperature.
Due to the excellent drainage, the soil warms up quicker in spring.
Improved ease of access.
Taller planter boxes make it easier for horticulturists with mobility issues to manage their garden, as they take away the need for crouching and bending down.
Improved plant productivity.
As a result of better drainage, soil control and deeper rooting, plants can grow healthier and much more productively in raised beds.

What plants are best for raised garden beds?

When you have raised beds, you can have a lot of different plants and it will be easy to maintain them. However, don’t overdo it, as all plants require nutrients, water and sunlight. If the competition is too great between them, no plant will reach its full potential. With that said, some of the plants which will thrive in a raised bed are:

Vegetables – Potatoes, for example, need a loamy soil which drains well while tomatoes thrive in nutrient-dense soil. Onions love quick-draining soil which should also be rich in nutrients. Basically, you can grow just about any vegetable in a raised bed.
Fruits – Most small fruits aren’t too picky about soil and weather conditions, so they will grow easily. Watermelons, honeydew and cantaloupe are larger and need room to grow. They also need frequent watering, so unless your beds are very large, maybe stick to smaller fruit such as strawberries, raspberries or currants.
Perennials – The only real concert you have with perennials is to provide them with some additional winter protection. Soils can get very cold in an elevated garden during the winter.

Before you start

There are a couple of things you need to consider before making your raised planter box. So, let’s go over what you need to do to prepare and build a raised bed.

Choose the area.
Make sure the spot you select for your planter box gets plenty of sunlight a day. Six to eight hours is ideal. Also, ensure that you’ll have enough space to walk around the raised bed and, if needed, fit a wheelbarrow on the path, too.
Choose the bed size.
Keep in mind that you’ll need to be able to reach all areas of the raised bed comfortably without having to walk on it. This will help you avoid compacting the soil. Of course, you won’t have these worries so much if you go for a waist-high planter box. Pay attention to the depth of your raised bed, as well. The minimum is 20cm. However, many plants will thrive in around 40-60cm, with most root vegetables needing at least 60cm to root successfully. The width and length of your raised garden bed can be whatever suits your needs best, just make sure to keep it narrow enough so you can reach the middle from the outside.
Choose your materials.
You’ll need to decide what your raised bed is going to be made of. Timber is by far the cheapest option, but it won’t last as long as other types. Timber frames are simple to build and don’t require any special skills. Railway sleepers are long-lasting, but very difficult to work with, and not to mention expensive. Masonry beds (made of bricks, stone or paving slabs) can be quite costly, but they have the advantage of being permanent. You’ll need some experience to work with them, though.

How to make a raised bed out of timber

In this guide, we’ll show you how to build a raised bed using timber – a simple and effective solution. Are you ready? Slip-on a pair of gloves to protect your hands and let’s get to it!

Choosing the wood

First and foremost, you’ll need to select the wood you’ll be working with. Will you go for treated or untreated wood? Treated lumber will last longer, but there are chemicals involved in the process. Regular pressure-treated wood is considered safe, but some gardeners have reservations and prefer other eco-friendly options.

Cedar and oak planks will last longer, even if they are untreated, due to the natural oils they release that prevent them from rotting. However, they are on the more expensive side.

Thicker boards will last a lot longer than a thin plank. Five-centimetre planks can last up to 10 years, even untreated!

So, take the time to decide on the best option for you and your garden.

Preparing the site

Before you start to build a raised bed, you’ll need to prepare the area where you will place it. You’ll want to create the planter box directly on the spot, as it can get heavy when it’s done. So, here is how to prepare the site for the raised garden planter.

Clear the area.
Clear all existing vegetation and debris from the spot.
Level the ground.
Make sure the ground is nice and level before you start building. You can check that with a spirit level.
Break up the soil.
Using a garden fork, break up the top layer of soil, getting it light and fluffy. This will help prevent compaction. Once you dig up the ground, remove any leftover roots you find.
Spread cardboard (optional).
If you like, you can spread cardboard over the growing area to prevent grass and weeds from growing through. Cardboard will rot into the soil over time. Before you place it down, remove any tape and staples. Make sure the pieces overlap by at least 15cm to stop the weeds from making their way through.

Building the raised bed

Now it’s time for the fun part – getting to build a raised bed! Let’s start with:

What you need

Four 5x5cm timber stakes
Four wooden planks, cut to the desired size
Galvanised screws
Wooden or rubber mallet
Drill
Screwdriver (regular or electric)
Spirit level

Now that you’ve gathered all your tools and materials, it’s time to start building.

Time needed: 2 hours.

Lay the planks down.
Lay your wooden planks flat down on the ground in the desired formation with their corners touching.
Add support posts.
Add the retaining stakes to each corner, hammering them at least 30cm deep into the ground. The part that remains above the surface should be as tall as your wooden boards.
Secure the planks to the posts.
Pre-drill in the desired spots to avoid splitting the wood. Use galvanised screws to prevent rusting.
Check that everything is level.
Using a spirit level, check that everything is nice, even and level.

Filling the frame with soil

Now that the frame is ready, you’ll need to fill it up with soil. First, select the right type of mix for the flowers, fruits or vegetables you’ll be planting. Use a mixture of good quality topsoil and organic material, such as compost and well-rotted manure. Firm down each layer as you go. When you’re done, allow the soil to settle for two weeks before planting.

Can I build a raised bed over a hard surface?

Yes, you can! Just make sure the soil is at least 60cm deep to allow for proper rooting. The no-dig method is particularly useful here and promotes strong soil structure as well!

To ensure good drainage, add a layer of coarse gravel, hardcore or stones underneath the soil. Cover them with a geotextile membrane to prevent clogging before adding the soil. However, if you’ll be planting deep-rooted plants, such as conifers or shrubs, skip adding the membrane.

What you should keep in mind

Due to the increased drainage, you may need to water your garden box plants more often. Keep an eye on their watering needs.
Nowadays, treated wood is considered safe as it doesn’t contain toxic chemicals or heavy metals. However, if you’re unsure, just line the inside of the frame with polythene.
Railway sleepers can contain creosote, which is dangerous when there is skin contact. To be on the safe side, avoid using them or make sure they haven’t been treated with creosote.
If you decide to build your raised bed on top of a hard surface, you need to keep into consideration the depth. Make the bed anywhere from 5 to 60 cm deep, so your plants can root deeply. This will be better for their health, if they are of the deep rooting species, and will reduce watering needs.

Don’t want to build a raised bed by yourself?

Do you lack time to build your own garden planter? Do you need help measuring, cutting and putting together the frame? Or maybe you just don’t feel like dealing with this by yourself. Don’t worry! Fantastic Services is here to help!

Our expert planting service includes building raised beds and planting your desired flowers or edible plant varieties. Take advantage of the great qualities and uses of raised beds with no effort at all! So, what are you waiting for? Book your expert gardener now using our simple online form!

Need a gardener?

Find a professional to help build your raised bed.

Takeaways

Raised beds are a great way to grow your veggies, berries or pretty perennials and provide easy access to gardeners with decreased mobility.
You can make raised beds from a wide range of materials.
Timber is the cheapest option, but is the least long-lasting.
You can fill the frame with whatever type of soil you need for the plants you’ll be planting.
Keep in mind that you may need to water more often due to the improved soil drainage.

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Did you find this article helpful? Did you manage to build a raised garden bed? Let us know in the comments!

Image source: Polly Ivanova Illustration