DIY Raised Garden Beds

A simple way to get started growing a garden is in a raised bed and it is not very hard to create that bed all yourself. Follow these easy step-by step instructions, or skip to the bottom for a video of the process and FAQs.

(If you aren’t sure if raised bed gardening is for you read my article about how to choose between in-ground or raised bed gardening.)

Steps to Create a Raised Garden Bed

• Construct the garden box
• Lay down grass or weed suppressor
• Add soil
• Add amendments
• Plant bed
• Surround with mulch if desired

How to Construct Easy Garden Boxes

I usually build my boxes 4 feet by 8 feet. The supplies needed to construct one box are:

• 3– 2x10x8 untreated boards
• 8– 3 inch deck screws
• Power drill/driver

Cut one of the 8 foot boards in half to make two 4 foot boards. All of the big box home improvement stores (Lowes, Home Depot, Menards) will cut a board for free that you are buying from them.

Dry fit the boards together with two long boards making the sides and short boards on the ends.

To avoid splitting the wood you can pre-drill screw holes with a drill bit that is narrower than the deck screws.

Secure the boards at a 90 degree angle at each corner with two screws.

Setting Up a New Raised Bed Garden Area

You can set up a raised garden bed on any surface that provides drainage–including a grass lawn. Just lay a weed barrier where you want to set up the garden bed to prevent grass and weeds from growing up through the bed. I like to use cardboard, but you can also purchase specialty barrier cloth.

Remove all tape and staples from boxes, and only use matte, not glossy coated boxes. And only use blank boxes, or those with a minimal amount of black, not colored, printing.

Overlap the edges to prevent weeds from coming through.

Fill the bed with raised bed mix. You do not need to use a liner in raised beds, though using a liner can extend the life of wooden beds.

Home improvement stores will sell bags of raised bed mix. Or a local landscaping company or nursery may sell and even deliver bulk mix.

To figure out how much soil you need–can you remember geometry from high school? This is where it comes in handy:

A 4×8 bed is 32 square feet. And the sides are 10 inches high, but you don’t want the soil all the way to the top or it will get washed out by rain and watering. So just fill it 9 inches high which is .75 of a foot. So .75 feet times 32 feet squared is 24 feet cubed.

You will need 24 cubic feet of soil to fill one 4×8 bed 9 inches deep.

A cubic yard is 27 cubic feet. If you are able to buy in bulk you could potentially save money by purchasing one cubic yard of soil to fill a 4x8x10 bed. You would just have a little bit extra you could just smooth out on the top, or fill in around your landscaping.

Homemade Raised Bed Mix

You can also make your own raised bed mixes. I have used both these mixes in the past.

DIY Topsoil Raised Bed Mix: use 1/3 each

• topsoil
• peat moss
• sand

DIY Soil-less Raised Bed Mix: use 1/3 each

• compost
• peat moss
• pearlite or vermiculite

I always add soil amendments when starting a new garden bed. I use both Bone Meal and Blood Meal according to the package instructions.

Each year you will need to add amendments, including compost, to your raised beds for good fertility.

The peat moss, sand, vermiculite and pearlite do not get “used up” and will not need to be replenished each year.

The fun part is planting your bed! The soil should be nice and loose which will make planting very easy. After getting rained on and watered a few times the soil will compact more.

A really nice way to finish out raised beds is to surround them with a pathway border of mulch or gravel over weed barrier.

This will help prevent weeds from getting into your beds by growing up under the edges from the outside. It is necessary in areas with crabgrass because of their aggressive runners. In areas without such troublesome weeds, leaving grass between the beds is an attractive option.

Watch the whole process of setting up two new garden beds in the video below.

FAQs

Should I use raised beds or garden in the ground?

Visit this post I wrote about how to decide between gardening in beds or in the ground.

Do garden beds have to be 4×8?

Garden beds do not have to be 4×8, it is simply a common size.

Most of my beds are 4×8, but I have a few 3×8 beds as well

What is the best size garden beds?

Garden beds should be no larger than 3-4 feet wide and 6-8 feet long. This is so that they are narrow enough that you can comfortably reach to the center without stepping on and compacting the soil in the bed. And this ensures they are not so long that you are tempted to cross the middle of the bed by stepping on and compressing the soil rather than walking around to get to the other side.

Do I have to pre-drill the wood?

Pre-drilling wood is not necessary, but makes it less likely that the wood will split when screwing together.

Can I put dirt in my raised garden beds or pots?

Plain “dirt” from you yard is generally not suitable for raised garden beds. Dirt in many parts of the country has too much clay and will be heavy and not allow water in the beds to drain well. Topsoil is mixed with peat moss and some sort of grit such as sand, pearlite or vermiculite to improve friability and drainage to be made suitable for raised beds.

Will animals get in my raised beds?

If you have groundhogs or moles you can staple a layer of hardware cloth inside the bottom of the bed before adding soil, this will prevent burrowing animals from coming up under your bed and eating your crops.

If you have rabbits you will probably need to make your raised beds taller to keep them out. You can stack two bed boxes on top of each other and secure with a 2×4 inside the corners.

Is using peat moss in the garden sustainable?

Though peat moss is only a slowly renewing resource many people choose to use it in gardening as part of a sustainable lifestyle. Peat moss is only required at the set-up of a garden and never needs to be “replenished” like you do with a yearly addition of compost or fertilizer. Home gardening and home composting for gardens have so many positive benefits for the planet that the one-time modest amount needed justifies its use.

(ie getting food from your backyard instead of letting it travel to you from a continent away, turning food waste back into useable fuel for garden growth rather than putting it in a plastic bag to pile up in a landfill, and others.)