Do Raised Bed Kits Need a Base?

An elevated gardening bed is another way to describe what’s typically known as a raised bed kit and is a way to store plants beyond just regular pots. And so, assuming you’ve created a raised bed kit for yourself, the question may spring into your mind on whether you then need to add a base to it? So, lets help you decide which method is best for your raised beds.

Adding a Base Layer

The raised bed will sit on the soil, so a base will give you a flat solid foundation for that soil. There are a few options for base materials:

Wood

Plywood sheets are simple to fit within the boards. They provide plenty of support and will last several years before needing replacement.

Stone

Limestone or paving slabs give drainage and stop grass and weeds taking over the bed. Thus, you should choose a breathable material like gravel, instead of concrete.

Weed Membrane

Garden weed membrane layers suppress the weeds and insulate the soil. Be sure to overlap and tape sheets for fear of weeds poking through.

Pros

·         Prevents the bed to sink or becoming distorted over time

·         Prevents leaching of soil from washing away or out

·         Can insulate soil and suppress weeds

Cons

·         Adds cost for materials and labour to install the base.

·         Harder to access soil for amendments without dismantling the bed.

No Base

It's also fine to simply place your raised bed directly on grass or soil. The trick is to make sure the ground below is levelled and properly compacted first.

Pros

·         Less materials and expense without a base.

·         Worms and beneficial organisms can still access soil from below.

·         Easy access to amend and turn soil by removing boards.

Cons

·         You gain potential for the boards to twist or the beds to sink unevenly over time.

·         Drainage holes may be invaded by grasses and weeds.

·         Lose some height from removing topsoil to level the ground.

Do You Need a Base?

For more smaller beds using going base free may well be adequate providing the ground is prepared properly. Beds on paving or patios also don't require an additional base.

For larger beds planted with heavier crops like tomatoes, or in very wet or uneven terrain, adding a base help maintain stability and drainage; whilst also protecting the roots of the plants.

If you want a bit of a middle ground option, you may go for gravel or weed membrane as a simple base layer to suppress weeds while still allowing worm access from below.

In the end, the decision you make will involve considering factors like soil quality, climate, bed size and planned crops. These should be your guiding light to the decision you inevitably make. Prefer accessibility or don’t want to spend on materials? Go base-free. Concerned about drainage or weeds? Add a base layer. Both approaches can work well; so, go with what best suits your garden's needs. And if you're looking for raised bed kits for your garden, be sure to check out our range.